Transcranial Doppler Ultrasound Results Research Articles

Successful Implementation Trial to Improve Stroke Risk (TCD) Screening in Children with Sickle Cell Anemia: A Roadmap to Care Enhancement

Stroke remains a devastating complication of sickle cell anemia (SCA). The STOP (Stroke Prevention Trial in Sickle Cell Anemia) protocol adopted in 2014 by the National Heart Lung and Blood Institute (NHLBI) guidelines includes stroke-risk screening using transcranial Doppler ultrasound (TCD) and prevention with chronic red cell transfusion therapy (CRCT). Theserecommendations were reinforced by the American Society of Hematology guidelines.However, despite the evidence supporting TCD screening in stroke prevention, the DISPLACE study (Dissemination and Implementation of Stroke Prevention Looking at the Care Environment) showed that real-world implementation was insufficient. To evaluate and improve sickle stroke screening, we conducted the NHLBI-funded multi-center DISPLACE study to identify barriers to TCD implementation and test novel methods for improving outcomes. DISPLACE is a 4-part study: 1) Retrospective calculation of TCD screening rates; 2) Assessment of barriers and facilitators; 3) Implementation trial to improve TCD screening and 4) Comparison of implementation sites to controls. Importantly, DISPLACE is the largest prospective study of children with SCA. This study employed a multi-level, multi-faceted cluster-randomized study of interventions to improve implementation rates of TCD. Methods: DISPLACE is a 28-center US consortium representing a range of: regions (urban vs rural), size (patient number), and institution type (academic vs community). In Part 1, sites performed a rigorous retrospective review of TCD screening from 2012-2016 to collect baseline rates. Part 2 included a barriers and facilitators assessment to TCD screening to inform the trial interventions: 1) Re-branding TCD as Sickle Stroke Screen, a meaningful name for SCD stakeholders; 2) Using a Single Coordinator (SC) for each site's TCD scheduling, and follow-up; 3) A custom designed provider-focused application, ProviderMinder TM (PM) created to remind providers to track TCD appointments and follow-up on results. When a TCD was due, PM alerted the provider to enter scan results or reason(s) missed. Once the TCD results (normal/conditional/abnormal) were entered in PM, providers were prompted to enter the next TCD date and/or intervention plan (if not normal). If a result was not entered, PM alerted the provider q3 days until the TCD was recorded as completed or rescheduled. The implementation trial (parts 3 and 4 of DISPLACE) included 16 sites that had the lowest TCD rates in part 1. The implementation trial included children with SCA aged 2-7 years (the group at highest risk for an abnormal TCD). Cluster randomization was used to allocate sites to PM alone (8 sites) or PM + SC (8 sites). The primary outcome was comparison of TCD rates between PM and PM+SC sites. Secondary outcomes included comparisons between 1) Part 3 sites' TCD rates and Part 1 baseline rates 2) Part 3 sites and control sites (to assess the impact of the educational rebranding of TCD). Results: Part 1 included 28 centers with 5246 children with SCA. Of the 16 intervention sites, 3 sites could not implement the interventions due to administrative issues but remained in the study and were re-designated as “control sites” and a 4th control site was added (they were not informed prospectively to avoid bias). Thus, there were 13 evaluable sites for the primary endpoint including 776 patients; 484 in sites using PM and 292 in sites using PM+SC. Control sites included 185 patients. The trial demonstrated superiority of the PM arm compared to the PM + SC arm (P<.0001 year 1 and p=0.002 year 2) in both years of implementation and in comparison, to the control sites (P<.0001 year 1, p=.009 year 2) with an overall improvement in mean TCD screening from part 1 by 25% (table 1). Conclusions: This was a highly successful implementation study in SCA. This study emphasizes the importance of performing barrier and facilitator assessments when introducing new guideline-recommended screenings into clinical practice. These findings also highlight the importance of ongoing quality assurance in SCA to ensure prevention practices are maintained. Despite the benefit of TCD (sickle stroke screening) in children with SCA, implementation was poor prior to these interventions. Results from this study will guide ongoing optimization of TCD screening and demonstrate the importance of adopting these interventions in the real world.

Dissemination and Implementation Looking at the Care Environment (DISPLACE) Study Evaluates Novel Interventions to Improve TCD (Sickle Stroke Screening) Implementation

Background: Stroke is a devastating complication of sickle cell anemia (SCA). The STOP (Stroke Prevention Trial in Sickle Cell Anemia) protocol was adopted in 2014 by the National Heart Lung and Blood Institute (NHLBI) guidelines for stroke-risk screening using transcranial Doppler ultrasound (TCD) and prevention with chronic red cell transfusion therapy (CRCT). These guidelines were upheld in the recent American Society of Hematology guidelines. Despite strong evidence supporting TCD screening (and CRCT initiation) in stroke prevention, wide scale implementation has not been achieved 4. DISPLACE (Dissemination and Implementation Looking at the Care Environment) is a multicenter, NHLBI-funded study conducted to identify barriers to TCD implementation and test novel methods for improving outcomes. DISPLACE is a 3-part study: 1) Retrospective assessment of current practice; 2) Assessment of barriers and facilitators; and 3) Implementation trial to improve TCD screening. This report focuses on Part 3. Methods: DISPLACE is a 28-center consortium across the US representing a range of: region (urban vs rural), size, and institution type (academic vs community). During Part 1, sites performed a rigorous retrospective chart review of children with SCA aged 2-16 years from 2012-2016 to collect baseline TCD rates. Part 2 included a rigorous mixed methods of the barriers and facilitators assessment to TCD screening was performed that resulted in 3 main interventions: 1.Re-branding TCD as Sickle Stroke Screen, a meaningful name selected by patients/families with SCD; 2. A Single Coordinator (SC) for each site's TCD screening, scheduling, and follow-up; 3. A newly designed application, Provider Minder (trademarked; PM). PMwas created to remind providers of patient appointments (versus reminders only sent to patients/families). Data entry in PM included birth date (to calculate age), city/state of residence, distance from SCD clinic and insurance. Date of last TCD was recorded to calculate date of next screen. When the TCD was due, the system alerted the provider to enter appointment completion or reason(s) why it was missed. TCD results were entered for PM to prompt for the next TCD date in a 10-14 month window (normal screens), 2-6 weeks (conditional screens), and intervention plan (abnormal screens): repeat scan in <2 weeks or other. If the provider failed to enter a patient's result, PM alerted the provider q3 days until the TCD was recorded as completed/rescheduled. Part 3 included 16 sites who successfully completed data entry in Part 1 and had the lowest TCD implementation rates. Part 3 inclusion criteria were the same as Part 1 except to specifically select children with SCA now aged 2-7 (the highest risk group to have an abnormal TCD in Part 1). All 28 sites received re-branding educational material (also disseminated to non-study sites). Cluster randomization was used to allocate sites to PM (8 sites) or PM + SC (8 sites). The primary outcome is which intervention results in the best TCD rates. Secondary outcomes include Part 3 sites’ improvement in TCD rates (compared to historical rates) and impact of the educational/rebranding of TCD to "Sickle Stroke Screen” in sites (4) that did not participate in Part 3. Stroke status, presence of CRCT after an abnormal TCD, missed TCD appointments, and medical decisions following TCD were also recorded. Results: Part 1 included 28 centers with 5223 individuals with SCA in the database. Of the 16 Part 3 sites, three could not implement the interventions due to a simultaneous change in hospital administration and site PI (1), inability to use PM due to institutional firewall (1) and inability to implement due to site specific issues (1). These 3 sites remained in the study as "control sites” and a fourth control site was added. Thus, 13 sites implemented the interventions with 877 patients; 520 were in sites using PM and 357 were in sites using PM+SC. Demographic data for the 877 children with SCA are in Table 1. The study ended on May 31, 2022. Calculations of TCD rates at all sites are in process and will be presented. Conclusions: Despite the benefit of TCD screening in children with SCA, guideline-based implementation remains poor. The range of barriers to screening has been previously reported by the DISPLACE study team and were used to design the study interventions. Results from this study will guide optimization of the intervention protocol proven to enhance TCD implementation. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

The Role of Hemoglobin and Hemolysis on Transcranial Doppler Velocities in Children with Sickle Cell Disease: Data from a Natural History Cohort

Background: Children with sickle cell disease (SCD) are at increased risk of cerebrovascular events that can impact neurocognitive development and quality of life (Colombatti 2016). Transcranial Doppler ultrasound (TCD) is a validated screening tool to identify pediatric SCD patients with the highest risk of stroke to start on a preventive chronic blood transfusion regimen (Estcourt 2020; Inusa 2019). High TCD velocities are an indication to start disease-modifying treatments or consider disease-curative options in children with SCD (Khemani 2019). However, real-world pediatric data on the correlation between hematological variables and TCD results are scarce (Salama 2020). We aimed to evaluate the distribution of TCD velocities in a pediatric natural history cohort and investigate their correlation with hematological variables and treatments.Methods: We performed a retrospective analysis on data from a prospective pediatric cohort followed from January 1,2009, to December 31, 2020 (censoring date). Standard care includes annual TCD from 2 years of age. We used transcranial Doppler imaging (TCDi) and classified results according to STOP criteria, considering terminal internal carotid artery (TICA) and middle cerebral artery (MCA) time-averaged maximum mean velocities (TAMMVs). Only complete exams with right and left measures available for both vessels were included. Hematological, clinical, and treatment variables were available from the natural history cohort database. Patients were divided according to genotype: HbSS/HbSβ 0 or HbSC/HbSβ +.Two-sample and Welch t-tests for unequal variances were used to compare mean hemoglobin (Hb) values and hemolysis markers in patients with and without abnormal/conditional TCDi results. Fisher and chi-square tests were used to compare categorical variables. Linear regression models were used to assess the effects of MCA and TICA TAMMVs as continuous variables on Hb. Odds ratios (ORs) for neurological events at different Hb levels were estimated using generalized estimated equations (GEE) with a binomial distribution, logistic function, and exchangeable correlation structure, allowing for correlation among repeated observations for the same patient. Multivariable GEE including characteristics and treatment variables were used to evaluate the association between neurological events and Hb.Results: Of the 182 SCD patients in the cohort, 169 had assessments of cerebral vasculopathy, and 155 had evaluable TCDi (583 exams). The median follow-up of the entire cohort was 79.8 months (range: 2.1-298.6 months) (interquartile range [IQR]: 36.9-126.3 months). The median age at the censoring date was 13.4 years (IQR: 9.1-17.5 years); 130 were HbSS/HbSβ 0, and 25 were HbSC/HbSβ +. Basic demographic characteristics of the cohort are in Table 1. The distribution of TCDi results was significantly different between genotypes (P<0.0001): in the HbSC/HbSβ + group (70 exams), 14 were normal (20.0%), and 56 were low (80.0%); in the HbSS/HbSβ 0 group (513 exams), 8 were abnormal (1.6%), 56 were conditional (10.9%), 311 were normal (60.6%), and 138 were low (26.9%). Only 37/138 (26.8%) low TCDi results were confirmed as stenosis at the nearest MRA. Patients with abnormal/conditional TCDi results had lower Hb (8.4 vs 8.9 g/dL, P≤0.0001) and higher reticulocyte counts (317,766 vs 262,750/mm 3, P≤0.0001), lactate dehydrogenase (843 vs 690 U/L, P=0.0012), and aspartate aminotransferase (61 vs 54 U/L, P=0.0007) compared with patients with normal/low results.We detected a linear correlation between TICA/MCA TAMMVs and Hb (Figure 1A and 1B). Univariate analysis showed significant inverse correlation between abnormal/conditional TCDi results and Hb considered as a continuous variable (OR: 0.484, P<0.001). In the multivariate analysis, the correlation between TCDi results and Hb remained significant; moreover, the risk of presenting abnormal/conditional TCDi results decreased with age (OR: 0.833, P<0.0064).Conclusions: This analysis from our natural history cohort shows a significant inverse correlation between Hb and MCA and TICA velocities, supporting the beneficial effect of higher Hb levels in reducing TAMMV. Disease-modifying therapies increasing Hb and reducing hemolysis could be helpful in reducing TAMMV in children with SCD.Funding: This study was supported by Global Blood Therapeutics. [Display omitted] DisclosuresAgodoa: Global Blood Therapeutics: Current Employment, Current equity holder in publicly-traded company. Beaubrun: Global Blood Therapeutics: Current Employment, Current equity holder in publicly-traded company. Biffi: BlueBirdBio: Consultancy, Other: Advisory Board. Colombatti: Global Blood Therapeutics: Research Funding; Addmedica: Consultancy; Forma Therapeutics: Consultancy; Novartis: Consultancy; NovoNordisk: Consultancy; BlueBirdBio: Consultancy; Global Blood Therapeutics: Consultancy; BlueBirdBio: Research Funding.

Evaluation of STOP Protocol Implementation for Abnormal TCD in Children with Sickle Cell Anemia at Risk for Stroke: Displace Consortium

Introduction: Without intervention, children with sickle cell anemia (SCA) have an 11% chance of overt ischemic stroke. The Stroke Prevention Trial in Sickle Cell Anemia (STOP) proved that children with SCA at increased risk of stroke can be identified using transcranial Doppler ultrasound (TCD) and, for those at risk, chronic red cell transfusion (CRCT) therapy is effective at preventing stroke. The 2014 National Heart, Lung, and Blood Institute (NHLBI) guidelines include annual TCD screening for children with SCA ages 2 - 16, and CRCT for primary and secondary ischemic stroke prevention. The NHLBI-funded Dissemination and Implementation of Stroke Prevention Looking at the Care Environment (DISPLACE) project was designed to 1.) evaluate current stroke screening and prevention practices in a 28-site consortium through intensive medical record review and an electronic data capture system, 2.) determine barriers and facilitators to stroke prevention practices through qualitative methods, and 3.) design and deliver interventions to increase rates of 'sickle stroke screening' using implementation strategies. The purpose of this abstract is to describe initial (pre-study) consortium actions following abnormal TCD results including whether all children had a repeat TCD within the next 4 weeks, whether they initiated CRCT, characteristics of which children received CRCT, and what alternate treatments were used. Methods: DISPLACE data collection years were 2012 - 2016. 5247 children with SCA who met criteria for annual TCD screening were entered into the electronic data capture system with clinical and demographic information. 163 children with abnormal TCD results were identified from the cohort database. Additional data were collected and subsequently adjudicated including timing of follow-up testing (repeat TCD or MRI) after abnormal TCD, implementation of CRCT following abnormal TCD, alternate treatment following abnormal TCD, and whether the STOP protocol was implemented. Data were analyzed using descriptive statistics. Results: In response to abnormal TCD, 75% of children had a repeat TCD ordered (Table 1). Of these, most repeat TCDs were completed within 3 months, with &amp;lt;10% delayed (longer than 12 weeks). CRCT was initiated in 69% of children with abnormal TCD (Table 2); of these, 17% had delayed initiation of CRCT. After abnormal TCD, 10% of families declined CRCT though suggested by providers. When some of these children later suffered an ischemic stroke, (20%) started CRCT at that time. The TWiTCH protocol (CRCT transitioning to HU in children without severe vasculopathy) was followed in about 1/4 of children on CRCT. Additional treatments following abnormal TCD included initiation of HU (64%) and bone marrow transplant (4%) (Table 3). Characteristics of children on CRCT are described in Table 4. Notably, of the 19 children whose CRCT was delayed, 15 (79%) had a stroke. There were 48 instances in which the STOP protocol was not implemented following abnormal TCD. Half of these were the result of decisions at the parent level (e.g., the parent refused CRCT, parent requested HU instead of CRCT). Five were provider decisions (e.g., provider suggested HU), and 15 were systems-level issues (e.g., repeat TCD was delayed). One was a combination of parent decision and system-level issue, and in 4 cases, the reason was unknown. Conclusions: In this nationally representative sample of children with SCA at risk for stroke, nearly ¾ of children had a repeat TCDs, suggesting confirmation of abnormal results was common prior to beginning CRCT. Notably, there were a large number of ischemic strokes in children when CRCT was delayed futher confirming the utility of the screening and stroke prevention protocol. An additional key concern identified in this study were the barriers to STOP protocol implementation. Common reasons for lack of implementation included the parent's decision for HU instead of CRCT, delays in CRCT initiation, and delays in obtaining repeat TCDs. Difficulties implementing the STOP protocol suggest the need for interventions for more rapid initiation of CRCT and stroke prevention. Disclosures Kanter: AGIOS: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy; Sanofi: Consultancy; bluebird bio, inc: Consultancy, Honoraria; Medscape: Honoraria; Guidepoint Global: Honoraria; GLG: Honoraria; Jeffries: Honoraria; Cowen: Honoraria; Wells Fargo: Honoraria; NHLBI Sickle Cell Advisory Board: Membership on an entity's Board of Directors or advisory committees; SCDAA Medical and Research Advisory Board: Membership on an entity's Board of Directors or advisory committees; BEAM: Membership on an entity's Board of Directors or advisory committees.

Characteristics of Children with Abnormal TCD in the Modern Era: Results from the Displace Consortium

Background: Stroke is one of the most devastating complications of sickle cell anemia (SCA). In 1998, the Stroke Prevention Trial in Sickle Cell Anemia (STOP), demonstrated that a high-risk group of children with SCA could be identified using Transcranial Doppler ultrasound(TCD) and that chronic red cell transfusion therapy (CRCT) could reduce the risk of first ischemic stroke in this group by over 90% (Adams, et al NEJM 1998).At STOP studyenrollment, 9.7% of children with SCA were identified as having an abnormal TCD. Baby HUG, (NCT00006400), an NHLBI supported phase III trial showed that severe anemia in SCA was associated with elevated white blood cell (WBC) and higher TCD velocities (Lebensburger, et al Blood 2010 ). It is unclear if lower hemoglobin (Hb) and/or higher WBC are causative of elevated TCD velocities or correlative biomarkers. As new disease therapies become available, it is important to know the current rate of abnormal TCD and characteristics of those patients. The DISPLACE (Dissemination and Implementation Looking at the Care Environment) project is a multicenter, NHLBI-funded study whose primary purpose is to identify barriers to implementation of stroke screening in SCA and test novel methods for improving outcomes. DISPLACE is a 3-part study: retrospective assessment of current practice, qualitative review of barriers and facilitators to screening and a cluster-randomized intervention implementation project to improve stroke screening. Part 1 of the study showedthat TCD screening rates varied widely among institutions ranging from 30-75.2% (mean 48.4%, median 47%). We are now reporting on the rate of abnormal TCD and the characteristics and outcomes of patients with abnormal TCD. Methods: DISPLACE is a consortium of 28 US centers. Each site performed a rigorous retrospective chart review of children with SCA aged 2-16 years from 2012-2016. To be eligible for inclusion, children must have been seen at their institution at least 2x during the study period and have confirmation of SCA. A custom electronic data capture (EDC) system facilitated entry of de-identified data including demographics, TCD and MRI results, medications, transfusions, and laboratory values. For children with SCA who had TCD or central nervous system imaging prior to 2012, these results were also entered into the EDC. TCD results were recorded in the EDC as normal, conditional or abnormal based on their institutional interpretation. Labs and vitals were entered for each patient in closest proximity to each TCD. Confirmation and adjudication of each abnormal TCD and associated outcomes were performed. Stroke status was also recorded as well as presence or absence of CRCT. Results: In total, 5247 children with SCA are included in the database of whom 5225 should have received a TCD. Of this cohort, 4210 children (80.6%) had at least one TCD recorded in the database. Within this group, 207 (4.9%) of children had an abnormal TCD and 816 (19.4%) had a conditional TCD. For those children who underwent TCD during the study (2012-2016) period, there were 105 (2.9%) abnormal TCD and 501 (13.6%) conditional TCD (Table 1). The mean age of children at the time of abnormal TCD was 6.6 years (range 2-16 yr). The majority of children were &lt;10 yr at first abnormal TCD. Over 30% of patients with an abnormal TCD were identified as receiving hydroxyurea.The mean Hb associated with an abnormal TCD was 7.8 +/- 1.1g/dl (range 5.7-10.6) and the mean WBC was 13 x109/L+/- 3.6 (range 3.9-23.4) (Table 2). Of the 105 patients with abn TCD during the study period, 18% had a stroke. Of the total 5247 patients in the database, 3093 (59%) had been prescribed hydroxyurea (HU) and 999 (19%) were prescribed CRCT. CRCT was prescribed most often for abnormal TCD (37%) or secondary stroke prevention (31%). Discussion: DISPLACE is the largest contemporary cohort of children with SCA. The incidence of abnormal TCD in the DISPLACE cohort is significantly lower than at randomization in the STOP study. The number of children receiving CRCT is higher than expected which may partly account for the decrease in frequency of abnormal TCD. Many patients with abnormal TCD were receiving HU when their TCD was abnormal and were started on CRCT. Additionally, while the outcomes of children with conditional TCD are still being evaluated, many of those children reverted to normal TCD without intervention. These data may also help us redefine the use and interventions needed for abnormal TCD. Disclosures Kanter: NHLBI: Membership on an entity's Board of Directors or advisory committees; bluebird bio, Inc.: Consultancy; SCDAA: Membership on an entity's Board of Directors or advisory committees; Guidepoint Global: Consultancy; GLG: Consultancy; Sangamo: Consultancy, Honoraria; Modus: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Imara: Consultancy; Cowen: Consultancy; Jeffries: Consultancy; Medscape: Honoraria; Rockpointe: Honoraria; Peerview: Honoraria. Adams:GBT: Consultancy, Other: consultancy to companies GBT and Blueburd Bio; Bluebird: Consultancy.

Ischemic stroke in children and young adults with sickle cell disease in the post-STOP era.

The Stroke Prevention Trial in Sickle Cell Anemia (STOP) and Optimizing Primary Stroke Prevention in Sickle Cell Anemia (STOP 2) trials established routine transcranial Doppler ultrasound (TCD) screening, with indefinite chronic red cell transfusions (CRCT) for children with abnormal TCD as standard of care. Implementation failures and limitations to the STOP protocol may contribute to continued ischemic stroke occurrence. In the "Post-STOP" study, we sought to assess the impact of the STOP protocol on the incidence of ischemic stroke in a multicenter cohort of former STOP and/or STOP 2 trial participants. A central team abstracted data for 2851 (74%) of the 3835 children who took part in STOP and/or STOP 2. Data included TCD and neuroimaging results, treatment, laboratory data, and detailed clinical information pertaining to the stroke. Two stroke neurologists independently confirmed each stroke using pre-specified imaging and clinical criteria and came to consensus. Among the 2808 patients who were stroke-free at the start of Post-STOP with available follow-up, the incidence of first ischemic stroke was 0.24 per 100 patient-years (95% CI, 0.18, 0.31), with a mean (SD) duration of follow-up of 9.1 (3.4) [median 10.3, range (0-15.4)] years. Most (63%) strokes occurred in patients in whom the STOP protocol had not been properly implemented, either failure to screen appropriately with TCD (38%) or failure to transfuse adequately patients with abnormal TCD (25%). This study shows that substantial opportunities for ischemic stroke prevention remain by more complete implementation of the STOP Protocol.

S856 ALTERATION OF IRON HOMEOSTASIS IN A MOUSE MODEL OF LIVER-STAGE PLASMODIUM INFECTION

Background: Stroke is one of the most devastating complications of sickle cell anemia (SCA). The STOP (Stroke Prevention Trial in Sickle Cell Anemia) protocol was adopted in 2014 by the National Heart Lung and Blood Institute (NHLBI) guidelines for stroke-risk screening using transcranial Doppler ultrasound (TCD) and prevention with chronic red cell transfusion therapy (CRCT) 1. Despite high-level evidence supporting the use of TCD screening (and CRCT initiation) in stroke prevention2,3, wide scale implementation has not been achieved 4. Aims: The DISPLACE (Dissemination and Implementation Looking at the Care Environment) project is a multicenter, NHLBI-funded study whose primary aim is to identify barriers to implementation of the STOP protocol and test novel methods for improving outcomes. DISPLACE is a 3-part study: retrospective assessment of current practice, qualitative review of barriers and facilitators to screening and a cluster-randomized intervention project using implementation science to improve TCD screening and CRCT implementation. We are reporting on part 1 of this project evaluating implementation rates of TCD screening and TCD outcomes (abnormal and conditional) in a large contemporary cohort. Methods: DISPLACE is a large multi-site study consortium of 28 centers across the United States representing a range of characteristics: region (urban vs rural), size, and institution type (academic vs community). Each site performed a rigorous retrospective chart review of children with SCA aged 2–16 years from 2012–2016. To be eligible for inclusion, children had to have been seen at their institution at least 2x/calendar year (for 1 year) and have confirmation of SCA. A custom electronic data capture (EDC) system facilitated entry of de-identified data including demographics, TCD and MRI results, medications, transfusions, and laboratory values. The primary study outcome is to assess implementation of TCD screening (per center). TCD screening rates were calculated per center (TCD/child/year/center). TCD results were recorded in the EDC as normal, conditional or abnormal. Stroke status was also recorded as well as presence or absence of CRCT. Data included missed TCD appointments and medical decisions based on TCD results. Results: The study included 28 centers. In total, 5223 individuals with SCA (50.2% male, 93.7% HbSS) are included in the database (5187 of those eligible in the study period). This is the largest cohort of children with SCA ever studied. TCD screening rates varied widely among institutions ranging from 30–75.2% (mean 48.4%, median 47%). Of the total in the database, 3718 patients had a TCD during the study period (71.7%). Of those patients who had a TCD, 138 (3.7%) had an ABNORMAL TCD per STOP guidelines which is notably lower than the STOP study with a rate of abnormal TCD of 9.7% at study entry. Characteristics of patients with abnormal TCD (vs. those without) are forthcoming. Summary/Conclusion: Despite the benefit of TCD screening in children with SCA, guideline-based implementation remains poor. The range of barriers to screening will help investigators optimize the intervention protocol to enhance TCD implementation. Notably, there are fewer children with abnormal screening rates in the modern era which may represent partial penetration of the STOP Protocol from prior screening and/or effect of disease-modifying therapy. Data analysis is in process to further qualify these findings.

S855 TCD IMPLEMENTATION RATES AND RESULTS IN THE MODERN ERA OF SICKLE CELL ANEMIA: RESULTS FROM THE DISPLACE STUDY

Background:Stroke is one of the most devastating complications of sickle cell anemia (SCA). The STOP (Stroke Prevention Trial in Sickle Cell Anemia) protocol was adopted in 2014 by the National Heart Lung and Blood Institute (NHLBI) guidelines for stroke‐risk screening using transcranial Doppler ultrasound (TCD) and prevention with chronic red cell transfusion therapy (CRCT) 1. Despite high‐level evidence supporting the use of TCD screening (and CRCT initiation) in stroke prevention2,3, wide scale implementation has not been achieved 4.Aims:The DISPLACE (Dissemination and Implementation Looking at the Care Environment) project is a multicenter, NHLBI‐funded study whose primary aim is to identify barriers to implementation of the STOP protocol and test novel methods for improving outcomes. DISPLACE is a 3‐part study: retrospective assessment of current practice, qualitative review of barriers and facilitators to screening and a cluster‐randomized intervention project using implementation science to improve TCD screening and CRCT implementation. We are reporting on part 1 of this project evaluating implementation rates of TCD screening and TCD outcomes (abnormal and conditional) in a large contemporary cohort.Methods:DISPLACE is a large multi‐site study consortium of 28 centers across the United States representing a range of characteristics: region (urban vs rural), size, and institution type (academic vs community). Each site performed a rigorous retrospective chart review of children with SCA aged 2–16 years from 2012–2016. To be eligible for inclusion, children had to have been seen at their institution at least 2x/calendar year (for 1 year) and have confirmation of SCA. A custom electronic data capture (EDC) system facilitated entry of de‐identified data including demographics, TCD and MRI results, medications, transfusions, and laboratory values. The primary study outcome is to assess implementation of TCD screening (per center). TCD screening rates were calculated per center (TCD/child/year/center). TCD results were recorded in the EDC as normal, conditional or abnormal. Stroke status was also recorded as well as presence or absence of CRCT. Data included missed TCD appointments and medical decisions based on TCD results.Results:The study included 28 centers. In total, 5223 individuals with SCA (50.2% male, 93.7% HbSS) are included in the database (5187 of those eligible in the study period). This is the largest cohort of children with SCA ever studied. TCD screening rates varied widely among institutions ranging from 30–75.2% (mean 48.4%, median 47%). Of the total in the database, 3718 patients had a TCD during the study period (71.7%). Of those patients who had a TCD, 138 (3.7%) had an ABNORMAL TCD per STOP guidelines which is notably lower than the STOP study with a rate of abnormal TCD of 9.7% at study entry. Characteristics of patients with abnormal TCD (vs. those without) are forthcoming.Summary/Conclusion:Despite the benefit of TCD screening in children with SCA, guideline‐based implementation remains poor. The range of barriers to screening will help investigators optimize the intervention protocol to enhance TCD implementation. Notably, there are fewer children with abnormal screening rates in the modern era which may represent partial penetration of the STOP Protocol from prior screening and/or effect of disease‐modifying therapy. Data analysis is in process to further qualify these findings.

Results from the Displace Consortium: Practice Patterns on the Use of Transcranial Doppler Screening for Risk of Stroke in Children with Sickle Cell Anemia

Abstract Introduction: Stroke is one of the most devastating complications of sickle cell anemia (SCA). The STOP (Stroke Prevention Trial in Sickle Cell Anemia) protocol has been adopted by National Heart Lung and Blood Institute (NHLBI) as the guideline for stroke screening using transcranial Doppler ultrasound (TCD) and prevention with chronic red cell transfusion therapy (CRCT). Evidence from the STOP I/II studies indicates the protocol is highly effective, yet wide scale implementation has not been achieved. The DISPLACE (Dissemination and Implementation Looking at the Care Environment) project is a multicenter, NHLBI funded consortium of 28 sites across the United States whose purpose is to identify barriers to the implementation of the STOP protocol and test novel methods for overcoming barriers. The purpose of this study was to use data on practice patterns to evaluate current measurement and practice standards at DISPLACE consortia sites. This abstract presents reported TCD screening and CRCT practices. Methods: A practice patterns survey was sent to the principal investigator (PI) for each DISPLACE site via RedCap ©. PIs were hematology/oncology specialty care providers for children with SCA. Sites represent urban and rural regions, large and small academic institutions, and community-based institutions. The survey was developed by the study investigators; questions were predominantly in a multiple-choice format. Items pertaining to TCD screening included: screening technique (including type of TCD); screening frequency; follow-up for abnormal, conditional, and inadequate results; standard value ranges. Results: All 28 PIs completed the survey. About half of the respondents were female (53.5%). Most identified as White (77.8%), followed by Asian (11.1%) and Black or African American (7.4%). Two identified as Hispanic or Latino (7.4%). Slightly more sites reported using standard TCD (57.1%) versus imaging TCD (TCDi) (42.9%). To calculate the time-averaged mean of the maximum (TAMM) velocities and characterize TCD results, nearly all sites use the middle cerebral artery (96.4%); a majority also use the anterior cerebral artery and/or the terminal internal cerebral artery or distal internal cerebral artery (71.4%). Fewer sites use the posterior cerebral artery (35.7%) or the basilar artery (14.3%). In 7.1% of sites, the radiologist determines which vessels to use during the exam. TCD screening is ordered for children with SCA annually in 92.9% of sites and every 6 months in 7.1% of sites. When TCD screening indicates abnormal TAMM velocities, 85.7% of sites initiate CRCT, 7.1% initiate hydroxyurea (HU) therapy, and 3.6% initiate both HU and CRCT. For additional evaluation, an MRI/MRA is obtained at 64.3% of sites. For high conditional results, the most common action is to initiate HU (67.9%). Other responses include obtaining an MRI/MRA (46.4%) and/or repeating the TCD in 2-4 weeks (25.0%), 6-8 weeks (35.7%), or 12-16 weeks (7.1%). Results deemed inadequate led to repeating the TCD in 2-12 weeks (57.1%) or in one year (3.6%), obtaining an MRI/MRA (57.1%), beginning HU therapy (7.1%), or no repeat TCD or change in management (3.6%). Actions for low conditional results include repeating the TCD (71.4%), obtaining an MRI/MRA (32.3%), and/or initiating HU therapy (57.1%). Surprisingly, sites use different TAMM ranges to characterize the normal/abnormal findings (Table 1). Conclusions: Nearly all DISPLACE sites order TCD screening annually, as recommended in the guidelines, with some ordering screening more frequently. A few sites did not report initiation of CRCT per STOP protocol for abnormal TCD results; however, over half of the sites reported following up with an MRI/MRA, which may suggest evaluating for vasculopathy prior to CRCT. Some sites reported beginning HU therapy for abnormal results; this may reflect consideration of patients for whom CRCT is not possible, but data were not collected for confirmation. Interestingly, results suggest a reliance on MRI/MRA since sites commonly reported ordering neuroradiology studies for abnormal, conditional, and inadequate TCD results. This may suggest an unclear pathway for children with borderline TCD results, and an area for future study. While reported value ranges closely approximated those in the STOP protocol, results indicate sites conducting screening with TCDi may use more conservative values than the validated protocol. Disclosures Phillips: NHLBI: Research Funding. Mueller:NHLBI: Research Funding. Schlenz:NHLBI: Research Funding. Melvin:NHLBI: Research Funding. Adams:NHLBI: Research Funding. Kanter:AstraZeneca: Membership on an entity's Board of Directors or advisory committees; bluebird bio: Membership on an entity's Board of Directors or advisory committees, Research Funding; Global Blood Therapeutics: Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Sancilio: Research Funding; NHLBI: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Research Funding; Apopharma: Research Funding; ASH: Membership on an entity's Board of Directors or advisory committees.

Ultrasound for the evaluation of stenosis after flow diversion

Background and purposeFlow diversion is a relatively new strategy used to treat complex cerebral aneurysms. The optimal method for radiographic follow-up of patients treated with flow diverters has not been...

Ischemic Stroke in Children and Young Adults with Sickle Cell Disease (SCD) in the Post-STOP Era

Background: The Stroke Prevention Trial in Sickle Cell Anemia (STOP) and Optimizing Primary Stroke Prevention in Sickle Cell Anemia (STOP 2) established routine transcranial Doppler ultrasound (TCD) screening with indefinite chronic red cell transfusions (CRCT) for children with abnormal TCD as standard of care. To identify children at high-risk of stroke, annual TCD screening is recommended from ages 2 to 16 years, with more frequent monitoring if the result is not normal. A reduction in stroke incidence in children with SCD has been reported in several clinical series and analyses utilizing large hospital databases when comparing rates before and after the publication of the STOP study in 1998. We sought to determine the rate of first ischemic stroke in a multicenter cohort of children who had previously participated in the STOP and/or STOP 2 trials and to determine whether these strokes were screening or treatment failures.Subjects and Methods: Between 1995 and 2005, STOP and STOP 2 (STOP/2) were conducted at 26 sites in the US and Canada. These studies included 3,835 children, ages 2 to 16 y with SCD type SS or S-beta-0-thalassemia. Participation in STOP/2 ranged from a single screening TCD to randomization. STOP 2 also had an observational arm for children on CRCT for abnormal TCD whose TCD had not reverted to normal. The Post-STOP study was designed to follow-up the outcomes of children who participated in one or both trials. 19 of the 26 original study sites participated in Post-STOP, contributing a total of 3,539 (92%) of the STOP/2 subjects. After exit from STOP/2, these children received TCD screening and treatment according to local practices. Data abstractors visited each clinical site and obtained retrospective data from STOP/2 study exit to 2012-2014 (depending on site) including follow-up TCD and brain imaging results, clinical information, and laboratory results. Two vascular neurologists, blinded to STOP/2 status and prior TCD and neuroimaging results, reviewed source records to confirm all ischemic strokes, defined as a symptomatic cerebral infarction; discordant opinions were resolved through discussion. For the first Post-STOP ischemic stroke, prior TCD result and treatment history subsequently were analyzed.Results: Of the 3,539 subjects, follow-up data were available for 2,850 (81%). Twelve children who had a stroke during STOP or STOP2 were excluded from these analyses resulting in data on 2,838 subjects. The mean age at the start of Post-STOP was 10.5 y and mean duration of follow-up after exiting STOP/2 was 9.1 y. A total of 69 first ischemic strokes occurred in the Post-STOP observation period (incidence 0.27 per 100 pt years). The mean age at time of stroke was 14.4±6.2 (median 13.8, range 3.5-28.9) y. Twenty-five of the 69 patients (36%) had documented abnormal TCD (STOP/2 or Post-STOP) prior to the stroke; 15 (60%) were receiving CRCT and 9 (36%) were not (treatment data not available for 1 subject). Among the 44 subjects without documented abnormal TCD, 29 (66%) had not had TCD re-screen in the Post-STOP period prior to the event; 7 of these 29 (24%) were 16 y or older at the start of Post-STOP, which is beyond the recommended screening age. Four of the 44 (9%) patients had inadequate TCD in Post-STOP (1 to 10.7 y prior to event). Six (14%) had normal TCD more than a year before the event (1.2 - 4 y); all but one of these children were younger than 16 y at the time of that TCD. Only 5 (11%) had a documented normal TCD less than 1 year prior to the event.Conclusions: In the Post-STOP era, the rate of first ischemic stroke was substantially lower than that reported in the Cooperative Study of Sickle Cell Disease, prior to implementation of TCD screening. Many (39%) of the Post-STOP ischemic strokes were associated with a failure to re-screen according to current guidelines, while only 11% occurred in children who had had recent low-risk TCD. Among those known to be at high risk prior to stroke, treatment refusal or inadequate treatment may have contributed. While TCD screening and treatment are effective at reducing ischemic stroke in clinical practice, significant gaps in screening and treatment, even at sites experienced in the STOP protocol, remain to be addressed. Closing these gaps should provide yet further reduction of ischemic stroke in SCD. DisclosuresNo relevant conflicts of interest to declare.

Impact of TCD Screening Protocol on the Incidence of Hemorrhagic Stroke in Children and Young Adults with Sickle Cell Disease

Background: Primary hemorrhagic stroke is a rare complication of sickle cell disease (SCD) that usually occurs in adults. The Stroke Prevention Trial in Sickle Cell Anemia (STOP) and Optimizing Primary Stroke Prevention in Sickle Cell Anemia (STOP 2) established routine transcranial Doppler ultrasound (TCD) screening with indefinite chronic red cell transfusions (CRCT) for patients with abnormal TCD as standard of care. Despite a notable improvement in the incidence of infarctive stroke in children with SCD after the introduction of TCD screening protocols, it is unclear how this protocol will affect the rate of hemorrhagic stroke. Presumably, early TCD screening and subsequent initiation of CRCT in high risk patients will prevent the progression of cerebral vasculopathy, which should decrease the risk of hemorrhagic stroke; however this has not been proven. Using the large multicenter cohort of children who participated in STOP and/or STOP 2 trials, we sought to assess whether the rate of hemorrhagic stroke was impacted by the use of TCD screening and/or CRCT.Subjects and Methods: Between 1995 and 2005, STOP and STOP 2 (STOP/2) were conducted at 26 sites in the US and Canada. These studies included 3835 children, ages 2 to 16 y with SCD type SS or S-beta-0-thalassemia. Participation in STOP/2 required at least a single screening TCD for randomization. Patients on STOP 2 also had an observational arm for children started on CRCT who had an abnormal TCD. The Post-STOP study was designed to follow-up the outcomes of children who participated in one or both of trials. For all participants the date of their last encounter in STOP/2 was defined as the start of their Post-STOP period. 19 of the 26 original study sites participated in Post-STOP, contributing a total of 3539 (92%) of the STOP/2 subjects. After exit from STOP/2, these children received TCD screening and treatment according to local practices. Data abstractors visited each clinical site and obtained retrospective data from STOP/2 study exit to 2012-2014 including follow-up TCD and brain imaging results, clinical information, and laboratory results. Two separate neurologists, blinded to STOP/2 status and prior TCD and neuroimaging results adjudicated all suspected strokes.Results: Follow-up data were available for 2850 of the 3539 subjects (81%). Twelve children who had a stroke during the STOP study period were further excluded from this analysis resulting 2838 subjects. The mean age at the start of Post-STOP was 10.5 years and mean duration of follow-up after exiting STOP/2 until time of last medical encounter was 9.1 years. A total of 31 patients had a primary hemorrhagic stroke during the Post-STOP observation period (incidence 0.12 per 100 pt years). The mean age at time of stroke was 16.2+5.6 (median 15.3 range (4.8-30.2) years of age. Of those 31 patients, only 52% had a TCD during Post-STOP prior to the event. Seven of those children who underwent screening had documentation of an abnormal TCD prior to the event (5 during STOP era and/or 3 Post-STOP). However, only 1/7 patients (14%) were documented on CRCT at the time of the stroke (4 patients were receiving HU and 2 patients had unknown treatment).Discussion: Although less common than infarctive stroke, patients with SCD are at increased risk for hemorrhagic stroke. There is an increased risk of mortality for patients who suffer from hemorrhagic stroke (up to 26% in some reports in the 2 weeks after the event). It is unclear if TCD screening and subsequent initiation of CRCT will impact the rate of hemorrhagic stroke in the long term. In our results, a similar incidence of primary hemorrhagic stroke was noted although the patients were overall younger than previously reported (16.5+/- 5.5 years versus 20-29 years in Cooperative Study of Sickle Cell Disease). Many patients who had a hemorrhagic stroke (48%) had not undergone TCD screening during the Post-Stop period. Additionally, although a safe stopping point for CRCT has not been established in patients who have had an abnormal TCD, only 1 patient was documented on CRCT at the time of the event (14%). Thus, it is unclear at this time whether TCD screening and subsequent, lifelong continuation of CRCT could have prevented these other events. Clearly, these results demonstrate that improved implementation of STOP protocol is needed as well as further evaluation of the impact of this protocol on the incidence of hemorrhagic stroke. DisclosuresNo relevant conflicts of interest to declare.

Transcranial Doppler Ultrasound (TCD) Outcomes for Children with Prior Normal TCD: Post-STOP Study Results

Background: The Stroke Prevention Trial in Sickle Cell Anemia (STOP) and Optimizing Primary Stroke Prevention in Sickle Cell Anemia (STOP 2) study established routine transcranial Doppler ultrasound (TCD) screening with indefinite transfusions for children with abnormal TCD as standard of care. Children with normal TCD studies have the lowest risk of stroke of ~0.5-1% per year (y). Annual TCD screening is usually recommended for these children to detect possible subsequent conversion to high risk. We sought to determine the frequency of TCD screening utilized in “real world” clinical practice and the TCD outcomes for children with prior normal TCD.Subjects and Methods: During STOP and STOP2 (STOP/2), 3,837 children, ages 2 to 16 y with sickle cell disease type SS or S-Beta-0-thalassemia underwent screening TCD. The Post-STOP study was designed to follow-up the outcomes of children who were screened for or participated in one or both of these randomized trials. 19 of the 26 original study sites participated in Post-STOP, contributing a total of 3,541 (92%) of the STOP/2 subjects. After exit from STOP/2, these children received TCD screening and treatment according to local practices. Data abstractors visited each clinical site and obtained retrospective data from STOP/2 study exit to 2012-2014 (depending on site) on follow-up TCD results and clinical information using standard data collection forms. The rates of TCD re-screening and the proportion of children who converted to abnormal TCD were calculated. Factors associated with conversion to abnormal TCD were assessed.Results: Of the 3,541 subjects, follow-up data were available for 2,838 (80%). The mean age at the last TCD study obtained in STOP/2 was 9.5 y and the mean age at last follow-up in Post-STOP was 19.6 y. The mean duration of follow-up after exiting STOP/2 was 9.2 y. Subjects were classified by their worst TCD in STOP/2: the TCD was normal in 1,814 (64%), conditional in 479 (17%), abnormal in 357 (13%) and inadequate 188 (7%). Among the 1,814 children with only normal studies in STOP/2, follow-up TCD screening was obtained in the Post-STOP era on 842 (46%) at a median rate of 0.28 TCD studies/y (range, 0.05-3.04/y). Among these children, 26 (3.1%) developed an abnormal TCD at a median of 11.5 y (2.2-18.2 y) from the last STOP/2 study, while 77.5% still had normal TCD at a median of 10.7 y (0.7-18.3 y) from last STOP/2 study. The worst follow-up TCD classification for this group with prior normal TCD was conditional in 9.7% and inadequate in 9.6%. Among those that converted from prior normal to abnormal TCD, 12 had an interval conditional study (at median 2.8 y, 0.98-9.2 y) while 14 children converted from normal to abnormal at a median of 4.2 y (1.4-12.7 y) without documented interval conditional study. Children who developed abnormal TCD were younger at STOP/2 study exit (4.9 vs. 7.8 y, p<0.001) and had higher TCD velocity at their last STOP/2 TCD study (154 vs. 136 cm/s, p<0.001) than children whose TCD remained normal. There was no significant difference between the time interval from the last STOP/2 TCD and the first Post-STOP TCD in these 2 groups.Conclusions: In clinical practice, follow-up TCD for children with prior normal TCD was performed less frequently than the generally recommended annual basis. Among children re-screened, the risk of conversion to abnormal TCD was relatively low, but re-screening with TCD identified a subset of at-risk children who could benefit from transfusions to prevent a potentially devastating outcome. Predictors of conversion to abnormal TCD included younger age and prior TCD velocity in the high normal range. DisclosuresAdams:Novartis: Consultancy.

The Use Of Transcranial Doppler Ultrasonography In Adult Patients With Sickle Cell Disease: A Retrospective Analysis

Background Unlike in children, Transcranial Doppler Ultrasound (TCD) can not currently be used to predict stroke risk in adults with Sickle Cell Disease, and this is confounded by an age related decline in TCD and lack of an established normal TCD velocity range for adults. In addition abnormalities in the extracranial circulation have been associated with increased incidence of stroke in children with SCD, but this has not been shown in adults. Aims To retrospectively review TCD and carotid duplex ultrasound results from adults with SCD and to correlate with neurological outcome. Methods TCD and carotid duplex data were collected from 112 patients from January 2003 to December 2012 and analysed retrospectively. Imaging and non-imaging TCD and carotid duplex were performed as a routine out-patient investigation as part of an annual review in the comprehensive adult sickle cell clinic in our unit. STOP velocity criteria were used for stroke risk stratification. Carotid disease was defined as non-significant (&lt;50%), moderate stenosis (50-69%) and severe disease (≥70%). Results The mean age of patients was 35.4 (range 17-79) years; 65% were female and 78% had HbSS. There were 5 patient exclusions based on the TCD findings; two were non-diagnostic and three had abnormal scans as part of childhood screening. The remaining 107 patients were divided into two groups; Group I patients had a normal neurological examination (n = 95) and Group II had an abnormal neurological examination with a clinical diagnosis of stroke that preceded TCD/carotid duplex examination (n = 12). In Group I there were 4 abnormal TCD scans according to STOP criteria; two showed significant asymmetry (&gt;25%) and two showed abnormally low velocities (&lt;50cm/s), one of whom subsequently developed a silent stroke. Although the remaining 91 patients had normal TCD findings; a limited TCD examination was noted in 6 patients and asymmetrical velocities that fell below the 25% threshold were observed in 7 patients, one of whom subsequently developed a symptomatic lacunar infarct. A further eight patients showed extracranial (ICA) disease and one of these also had evidence of a silent stroke on MRI. In Group II, 5 patients showed abnormal TCD findings; four had low velocities (&lt;50cm/sec) and one had low velocities and significant asymmetry. Six patients had severe extracranial ICA stenosis or occlusion on carotid duplex. There was a significant increase in the incidence of abnormal TCD (C2=19.4, p&lt;0.001) and duplex findings (C2=16.2, p&lt;0.001) in patients in Group II compared to Group I. Conclusions Routine screening of adults with SCD using TCD did not show any asymptomatic patients with elevated TCD flow-velocities (&gt;170cm/s), confirming previous studies. However, other abnormal ultrasound findings were observed including; abnormally low or asymmetric TCD velocities and extracranial ICA disease. These abnormalities were associated with stroke in three cases; TCD asymmetry preceded a lacunar infarct by five years, abnormally low velocities preceded a silent infarct by two years and severe extracranial ICA stenosis was associated with a silent infarct. There was a significantly increased incidence of abnormal ultrasound findings in patients who had neurological symptoms (91.6% versus 12.6%). Further investigation of the incidence and implications of abnormal TCD and extracranial carotid duplex findings in adults with sickle cell disease is required. Longitudinal follow-up of patients with low or asymmetric velocities and ICA disease will clarify if these abnormalities are associated with increased neurological morbidity; if so, intervention may be justified. The traditional STOP criteria of raised TCD velocities are inadequate in the adult sickle population, new velocity criteria are required to stratify the risk of stroke in this population. Disclosures: Howard: Sangart: Membership on an entity’s Board of Directors or advisory committees.

Abstract WP410: Comparison of Transcranial Doppler Ultrasound with Intracardiac Echocardiography in the Detection of Cardiac Right-to-Left shunt in Children and Young Adults

Background and Objectives: Right to left shunts (RLS) found with patent foramen ovale are implicated in the pathophysiology of cryptogenic stroke, migraine headaches as well as decompression illness. Our dysautonomia clinic has described a syndrome of neurocardiogenic syncope, stroke, migraine headaches and positive tilt table testing associated with atrial septal defects (ASD). All patients underwent transcranial Doppler ultrasound (TCD) and intracardiac echocardiogram (ICE) testing. Methods: We performed a restrospective analysis of a prospectively obtained registry of patients that underwent shunt testing ± endovascular ASD closure. All patients had previously undergone a transthoracic echocardiogram bubble study (TTE) to confirm a RLS. Patients underwent general anesthesia and bilateral TCD monitoring of the middle cerebral artery. Valsalva was produced by the anesthesiologist (40mm Hg). Simultaneous assessment of RLS was performed using ICE and TCD monitoring after injection of agitated saline into the femoral vein sheath. If negative, a direct right atrial injection was performed. The size of ASD was measured by ICE independent of TCD results. Results: Between 9/2010 and 7/2012, 112 patients underwent testing. Patient characteristics are displayed in the table. RLS was found in 82.1, 81.1, and 71.4% by TTE, ICE and TCD, respectively. After peripheral injection (n=85), when compared to ICE, TCD had a sensitivity, specificity, PPV, NPV and accuracy of 96, 100, 100, 64 and 95%, respectively. Combined peripheral and intracardiac injections (N=112) when compared to ICE, TCD had a sensitivity, specificity, PPV, NPV and accuracy of 89, 100, 100, 66 and 90%, respectively. Conclusion: Transcranial Doppler ultrasound detection of right to left shunts remains a highly accurate, non-invasive tool. If closure of cardiac shunts is proven to prevent stroke, migraines or treat neurocardiogenic syncope, TCD might be considered the preferred screening method.

The identification of right-to-left shunts using contrast transcranial Doppler ultrasound: performance and interpretation modalities, and absence of a significant side difference of cardiac micro-emboli

Cardiac and extracardiac right-to-left shunts can be identified by transesophageal echocardiography (TEE) as well as by transcranial Doppler ultrasound (TCD) using contrast agents that do not pass the lungs. Currently, the appropriate performance of a Valsalva manoeuvre (VM) to provoke the shunt, the use of different contrast agents and the classification of the TCD results are still under debate. In this study, we looked also at possible side effects of provoked cardiac micro-emboli in the left and right hemisphere. Seventy-one patients were investigated by both TEE and bilateral TCD of the middle cerebral arteries. The following protocol was applied in a randomized way: (1) Echovist®-300 without VM; (2) Echovist®-300, VM for 5 seconds starting 5 seconds after the beginning of contrast injection; (3) repetitive short VMs in between 2 and 13 seconds after the beginning of Echovist®-300 injection; and (4) repetitive short VMs in between 2 and 13 seconds after the beginning of agitated saline injection. Only if one of the tests (2-4) was negative, this particular negative test was repeated. Use of Echovist®-300, but not of saline yielded 100% sensitivity in the detection of TEE-proven shunts. The repetitive VM was slightly superior to the conventional VM. Introduction of a threshold of two or even three microbubbles produced less falsely positive TCD results in comparison to the TEE. There was no difference in microbubbles. TCD using Echovist®-300 is a sensitive method to identify TEE-proven cardiac right-to-left shunts. Repetitive VM is an alternative to conventional VM.

The clinical utility of transcranial Doppler ultrasound in suspected vertebrobasilar ischemia.

The impact of transcranial Doppler ultrasound (TCD) on the management of 107 consecutively referred patients with suspected vertebrobasilar ischemia was studied. Physicians who referred patients for TCD of the posterior circulation were interviewed before and after being given the results of the TCD examination. Management plans devised prior to knowledge of the TCD results were compared to those devised after TCD results were given. Management changed in 42% of the patients after TCD results were given, and there was a 58% reduction in the use of angiography (p = 0.04) and a 128% increase in the use of aspirin (p = 0.005). Changes in the use of anticoagulants and other diagnostic or therapeutic approaches were not significant. TCD appears to have a significant impact on the management of patients with suspected vertebrobasilar ischemia.

A randomized trial of nicardipine in subarachnoid hemorrhage: angiographic and transcranial Doppler ultrasound results

Calcium antagonist drugs were proposed for use in patients with recent aneurysmal subarachnoid hemorrhage (SAH) because of their ability to block the effects of a wide variety of vasoconstrictor substances on cerebral arteries in vitro. It was suggested that these agents might, therefore, be useful in ameliorating cerebral vasospasm and its ischemic consequences which frequently complicate SAH. This hypothesis was tested in an arm of a randomized double-blind placebo-controlled trial of high-dose intravenous nicardipine in patients with recently ruptured aneurysms. Participating investigators were required to send selected copies of all admission and follow-up angiograms obtained between Days 7 and 11 following hemorrhage (the peak period of risk for vasospasm) to the Central Registry of the Cooperative Aneurysm Study for blinded interpretation and review for the presence and severity of angiographic vasospasm. In centers with transcranial Doppler ultrasound (TCD) capabilities, middle cerebral artery (MCA) mean flow velocities were measured and recorded. Angiograms obtained between Days 7 and 11 were available for 103 (23%) of 449 patients receiving nicardipine and 121 (26%) of 457 receiving placebo. There was a balance of prognostic factors for vasospasm between the groups. Fifty-one percent of placebo-treated patients had moderate or severe vasospasm on "Day 7-11 angiograms" compared to 33% of nicardipine-treated patients. This difference is statistically significant (p < 0.01). Sixty-seven (49%) of 137 placebo-treated patients examined with TCD between Days 7 and 11 had mean MCA flow velocities exceeding 120 cm/sec compared to 26 (23%) of 112 nicardipine-treated patients (significant difference, p < 0.001). These data suggest that high-dose intravenous nicardipine reduces the incidence and severity of delayed cerebral arterial narrowing in patients following aneurysmal SAH.