TIA Patients Research Articles

PP22 Alternative care pathways for patients with low risk tia attended by emergency ambulance: a national survey

BackgroundPatients presenting to emergency ambulance services with TIA are usually conveyed to the nearest Emergency Department (ED) with subsequent referral to specialist assessment at a TIA clinic within one week...

P5198The occurrence of stroke and TIA in patients with peripheral artery disease and the effect of ticagrelor versus clopidogrel in EUCLID

P5198The occurrence of stroke and TIA in patients with peripheral artery disease and the effect of ticagrelor versus clopidogrel in EUCLID

42 How hard do we look for atrial fibrillation?

Brief introductionIdentifying atrial fibrillation (AF) after ischaemic stroke changes the recommendation from antiplatelets to anticoagulation. Currently, there is no clear consensus on the duration of rhythm monitoring post stroke. EMBRACE...

Transient Ischaemic Attack 999 Emergency Referral (TIER): a cluster randomised feasibility trial facilitated by data linkage

ABSTRACT
 Background Studies demonstrate TIA patients are at risk of further TIAs, stroke and death. TIA incidence is unknown, however estimated at 35 per 100,000 people annually in the UK, costing approximately £7 billion. Many TIA patients call 999, are assessed, stabilised and conveyed to Emergency Department (ED). Rapid assessment of TIA severity and risk and intervention is emerging as the new standard for TIA care leading to alternative pathways with direct referral to specialist services. However, uncertainties exist over this new model of care.
 We will develop and assess feasibility of paramedic assessment and referral of low-risk TIA patients directly to TIA clinic for early review, thus providing timely specialist review without: adverse consequences; inconvenience of ED attendance; unnecessary cost to the NHS.
 MethodsThis feasibility trial is designed to test the methods of a pragmatic cluster randomised trial, utilising data linkage for capturing outcome data, but with a qualitative component. To develop the treatment protocol, training and referral processes, working with clinicians/stakeholders, we will conduct:
 
 survey across UK ambulance services to find referral pathways for low-risk TIA patients
 systematic review of TIA prehospital care
 paramedic focus groups pre-implementation
 
 Then:
 
 randomise paramedics (intervention/control)
 recruit patients
 interview patients, key clinicians and service managers
 collect routine data via data linkage using the SAIL databank
 hold paramedic focus groups post-implementation
 
 We will:
 
 measure uptake and compliance with treatment protocols
 validate TIA assessment tool
 analyse qualitative data
 pilot recruitment processes
 test data collection methods
 estimate key outcomes effect size to inform full trial sample size calculation
 
 ResultsWill inform full trial development using criteria: intervention acceptability to practitioners and patients; trial design feasibility; outcome data completeness.
 Conclusions
 
 If indicated, full trial conducted
 If not, but positive results - advise intervention development for immediate implementation
 If not, but negative results – advise delivery of intervention should cease.

Cerebral blood flow and auto-regulation in acute TIA patients from a general hospital in Qatar (P4.253)

Cerebral blood flow and auto-regulation in acute TIA patients from a general hospital in Qatar (P4.253)

Clinical outcomes and a high prevalence of abnormalities on comprehensive arterial and venous thrombophilia screening in TIA or ischaemic stroke patients with a patent foramen ovale, an inter­atrial septal aneurysm or both

IntroductionData are limited on the optimal management of cryptogenic TIA/stroke patients with a patent foramen ovale (PFO)±inter-atrial septal aneurysm (IASA), especially with an inherited thrombophilia. MethodsProspectively-collected data on TIA/ischaemic stroke patients with PFO, IASA or both who received ‘goal-directed secondary-prevention medical treatment’ were analysed. All patients had trans-oesophageal echocardiography, anti-nuclear, anti-cardiolipin, anti-beta 2 glycoprotein I antibodies, rheumatoid factor, lupus anticoagulant, protein C&S, anti-thrombin, factor VIII activity, activated protein C resistance, Factor V Leiden, prothrombin gene and MTHFR-c.677C>T mutation screening. ENA and homocysteine were assessed in the latter study period. ResultsEighty-three patients were recruited. Mean follow-up: 48.1months. Forty-seven patients (56.6%) had an isolated PFO, 32 (38.6%) a PFO and an IASA, and 4 (4.8%) an IASA alone. Eighteen (21.7%) had ≥1 abnormality on thrombophilia screening. The most important abnormalities which lead to treatment changes in 11 patients (13.3%) were primary anti-phospholipid syndrome (N=3; 3.6%), protein S deficiency (N=2; 2.4%) hyper-homocysteinaemia (N=6/72 screened, 8.3%). Four patients (4.8%) opted for PFO closure: two with protein S deficiency, and two with no identified thrombophilia. Seven (8.4%) had recurrent TIA/ischaemic stroke during follow-up (overall annualised incidence: 2.1%), of whom five had a PFO alone and two a PFO and IASA. DiscussionComprehensive arterial and venous thrombophilia screening is warranted in TIA/ischaemic stroke patients with a PFO±IASA, is conclusively abnormal in over a fifth, and informed important decision-making regarding individualised therapy in 13.3% of patients. The incidence of recurrent vascular events in this population is low on optimal, personalised secondary-prevention treatment, even with an underlying thrombophilia.

Characterization of blood flow through intrapulmonary arteriovenous anastomoses and patent foramen ovale at rest and during exercise in stroke and transient ischemic attack patients.

We determined whether stroke and/or TIA subjects have exercise-induced blood flow through intrapulmonary arteriovenous anastomoses (QIPAVA ) and/or patent foramen ovale (QPFO ) and a genetic predisposition for ischemic stroke. Twenty-eight stroke and/or TIA subjects (33-63years old) underwent transthoracic saline contrast echocardiography concomitant with transcranial Doppler to detect QIPAVA and QPFO at rest and during supine exercise with and without breathing 100% O2 . We also examined genetic polymorphisms in FV Leiden (G1691A; rs6025), factor II (FII) prothrombin (G20210A; rs1799963), methylene tetrahydfropholate reductase (C677T, rs1801133), and plasminogen-activator inhibitor-1 (PAI-1) (4G/5G; rs1799889) and angiotensin-converting enzyme (ACE; I/D, rs4646994) in 24/28 subjects. No subject without PFO had QIPAVA at rest (n=17), but 12/17 did with exercise. All PFO subjects had QPFO at rest (n=11) and 7/11 had either QIPAVA or QPFO with exercise. Breathing 100% O2 during exercise reduced or eliminated left heart contrast in all subjects. Gene analyses revealed that 15/24 patients were either heterozygous or homozygous for methylenetetrahydrofolate reductase gene polymorphism; 4G/4G and 4G/5G genotypes of plasminogen-activator inhibitor-1 were present in 7/24 and 13/24 patients, respectively; polymorphisms of ACE D/D genotype were present in 6/24 and I/D in 14/24 patients. Having both I/D and 4G/4G genotypes was more prevalent in PFO+ subjects (P=.03), and there was a trend (P=.06) for PFO- subjects to have a greater D/D genotype prevalence. Novel genetic predispositions reported here in PFO subjects should be investigated further in larger stroke and/or TIA patient datasets.

Stroke unit care in germany: the german stroke registers study group (ADSR)

BackgroundFactors influencing access to stroke unit (SU) care and data on quality of SU care in Germany are scarce. We investigated characteristics of patients directly admitted to a SU as well as patient-related and structural factors influencing adherence to predefined indicators of quality of acute stroke care across hospitals providing SU care.MethodsData were derived from the German Stroke Registers Study Group (ADSR), a voluntary network of 9 regional registers for monitoring quality of acute stroke care in Germany. Multivariable logistic regression analyses were performed to investigate characteristics influencing direct admission to SU. Generalized Linear Mixed Models (GLMM) were used to estimate the influence of structural hospital characteristics (percentage of patients admitted to SU, year of SU-certification, and number of stroke and TIA patients treated per year) on adherence to predefined quality indicators.ResultsIn 2012 180,887 patients were treated in 255 hospitals providing certified SU care participating within the ADSR were included in the analysis; of those 82.4% were directly admitted to a SU. Ischemic stroke patients without disturbances of consciousness (p < .0001), an interval onset to admission time ≤3 h (p < .0001), and weekend admission (p < .0001) were more likely to be directly admitted to a SU. A higher proportion of quality indicators within predefined target ranges were achieved in hospitals with a higher proportion of SU admission (p = 0.0002). Quality of stroke care could be maintained even if certification was several years ago.ConclusionsDifferences in demographical and clinical characteristics regarding the probability of SU admission were observed. The influence of structural characteristics on adherence to evidence-based quality indicators was low.

Anticoagulant Therapy In Ischemic Stroke Or TIA

Stroke is the leading cause of disability and the third leading cause of death . Anticoagulants have been used to treat patients with acute ischemic stroke for many years. Despite their widespread use, the usefulness of emergency anticoagulation is a subject of debate. Disagreements exist about the best agent to administer, the route of administration, the use of a bolus dose to start treatment, the level of anticoagulation required, and the duration of treatment. There are 2 types of anticoagulants: Parenteral and oral. Heparin is an anticoagulant that used parenteral. Oral anticoagulants are including Warfarin and new anticoagulants such as Dabigatrn,Rivaroxaban ,Apixaban and other newer drugs.In patients with noncardioembolic ischemic stroke or TIA antiplatelet agents are treatment of choice and preferred to anticoagulants.In cardioembolic ischemic stroke or TIA with high risk of reembolization anticoagulants are considered as preferred treatment. Warfarin, apixaban10mg/d ,Rivaroxaban20mg/d, and dabigatran 150 mg/d are all indicated for the prevention of recurrent stroke in patients with nonvalvular AF, whether paroxysmal or permanent.Also anticoagulant therapy is recommended for ischemic stroke or TIA patients in the setting of acute MI, atrial or ventricular thrombosis or dilated and restricted cardiomyopathy. Some valvular heart diseases are other indication for anticoagulant therapy in ischemic stroke or TIA patients.Ischemic Stroke or TIA in patients with Cerebral vein thrombosis and known hypercoagulable state specially anti phospholipid antibody syndrome are other indications for anticoagulant treatment.

Abstract TP414: Are Periodic Limb Movements and Obstructive Sleep Apnea Associated with Atrial Fibrillation or Resistant Hypertension in Stroke and TIA Patients?

Introduction: Periodic limb movements (PLMs) and obstructive sleep apnea (OSA) have been associated with an increased risk of cardiovascular disease. There are limited data on the frequency of PLMs and OSA among a diverse cohort of stroke patients and their association with resistant hypertension and atrial fibrillation (AF). Hypothesis: Stroke and TIA patients with PLMs or moderate-severe OSA are more likely to have resistant hypertension and AF than patients without these findings on diagnostic polysomnography (PSG). Methods: Consecutive stroke and TIA patients referred by a vascular neurologist for PSG from October 1, 2012 to September 30, 2015 were included in this analysis. Baseline clinical characteristics and PSG results were collected retrospectively. The frequency of PLMs (mild ≥5/hour, severe ≥15/hour), arousals due to PLMs (≥5/hour), and moderate-severe OSA (Apnea-Hypopnea Index≥15) was evaluated by PSG to determine their association with AF and resistant hypertension, defined as patients whose blood pressure was not at goal with 3 antihypertensive agents of different classes or controlled with 4 or more medications. Results: Of 103 patients (mean age 60±15 years, 50% female, 61% non-white, 76% ischemic stroke, 23% resistant hypertension) who underwent PSG (median time from cerebrovascular event to PSG 5 months), 48% had mild PLMs, 28% had severe PLMs, 14% had frequent PLM arousals and 22% had moderate-severe OSA. In multivariable analyses, non-white race was associated with lower likelihood of mild (OR 0.32, 95% CI 0.13 to 0.80) and severe PLMs (OR 0.29, 95% 0.10 to 0.79) and female sex was associated with lower likelihood of frequent PLM arousals (OR 0.38, 95% CI 0.14 to 1.00). Factors associated with moderate-severe OSA included older age (OR 1.06, 95% CI 1.016 to 1.106) and the presence of AF (OR 4.26, 95% CI 1.17 to 15.44). There was no significant association between PLMs, PLM arousals or moderate-severe OSA with resistant hypertension. Conclusions: A significant number of stroke and TIA patients have PLMs and moderate-severe OSA. Stroke and TIA patients with AF are more likely to have moderate-severe OSA and should be referred for PSG. The presence of resistant hypertension was not associated with PLMs or moderate-severe OSA in our study.

Abstract WP280: Barriers to the Early Management of Patients With Transient Ischemic Attack in Low and Middle Income Countries

Background: Although much progress has been made in the acute ischemic stroke care in low- and middle-income countries (LMIC), there is a paucity of specific data on the early management of TIA patients. Patients with TIA present a substantial risk of stroke during the first few hours of symptom onset, when secondary prevention therapies should be urgently initiated. Therefore, hospital admission may offer some advantages for early management. Our aim was to evaluate the benefit of hospital admission of TIA patients in a LMIC. Methods: All TIA patients who arrived at our emergency room (ER) between March 2015 to March 2016 were admitted to the hospital. All patients were submitted to the following diagnostic protocol: brain imaging, intra and extracranial vascular imaging, echocardiography (TT and or TEE) and ECG. Baseline, imaging characteristics and early outcome were analyzed. Results: Among 845 consecutive stroke patients evaluated at our ER, 12.8% were diagnosed as TIA. Although vascular risk factors and presentation with weakness or speech disturbances were frequent findings among our TIA patients, only 1 in 5 patients (17.4%) required specific treatment (anticoagulation or carotid revascularization). In addition, half of our patients were classified as cryptogenic TIA. The average length of stay was 7.03 and there were no in-hospital stroke or death. We did not detect significant differences in demographics, risk factors and imaging features between patients that received standard vs. specific treatment. Conclusions: Many TIA patients with mild symptoms may not have reached our ER and among those who were evaluated some may not have required hospital admission. Clustering of risk factors among TIA patients may not be a variable helpful to identify high-risk patients in LMIC. A 24/7 emergency TIA clinic may be an option to improve urgent treatment and reduce acute care cost.

Abstract 1: Dual Antiplatelet Therapy is More Effective for Multiple Acute Infarcts: Subgroup Analysis of Chance

Background and Purpose: TIAregistry.org project showed that TIA and minor stroke patients with multiple acute infarctions (MAIs), which represent mechanisms of embolism, are at higher risk of recurrent stroke as compared to those with none or single acute infarction (SAI). We hypothesis that patient with MAIs may be more susceptible to dual antiplatelet therapy. Methods: We compared clopidogrel plus aspirin with aspirin alone with regard to their effectiveness and safety for prevention of stroke recurrence among non-cardiac TIA and minor ischemic stroke patients with different infarction patterns (no acute infarction, SAI, or MAIs) in the imaging subgroup from the Clopidogrel in High-Risk Patients with Acute Non-disabling Cerebrovascular Events (CHANCE) trial. The efficacy and safety outcome were stroke recurrence and moderate-to-severe bleeding event at 90 days respectively. Results: Overall, 1089 patients at 45 centers in CHANCE trial were included. The rate of recurrent stroke was 14.2%, 8.7%, and 2.0% in patients with MAIs, SAI and no infarction respectively at 90 days. Increased risk of stroke recurrence was observed in patients with MAIs (HR, 5.9; 95% CI, 2.3-15.2) and SAI (HR, 4.1; 95% CI, 1.6-10.7) (Figure A) as compared to those without infarction. The dual antiplatelet treatment was superior to aspirin alone for reducing the risk of recurrent stroke in patients with MAIs (HR 0.48; 95% CI, 0.25- 0.92; P = 0.03) but not in patients with SAI and without acute infarction with P=0.046 for interaction (Figure B-D). The effect of treatment assignment on bleeding did not vary among groups with different infarction patterns ( P &gt;0.05 for all). Conclusions: Patients with MAIs had the highest risk for stroke recurrence among patients with different infarction patterns. Patients with MAIs may benefit the most clinically from dual antiplatelet therapy and dual antiplatelet therapy does not increase the risk of hemorrhage among any groups.

Abstract TMP103: A Culturally-tailored, Skills-based Intervention to Reduce Vascular Risk in a Multi-ethnic Group of Mild/Moderate Stroke Survivors: An Interim Analysis from the DESERVE Trial

Introduction: Secondary stroke prevention strategies have proven suboptimal in underserved communities and minority populations. Methods: The Discharge Educational Strategies for Reduction of Vascular Events (DESERVE) trial tested the efficacy of an innovative skills-based intervention focused on risk perception, medication adherence, and patient-physician communication (vs. usual care enhanced with educational material [EUC]) on blood pressure (BP) reduction among mild/moderate stroke (NIH Stroke Scale ≤ 15) or TIA patients at 1 year post discharge. Study participants were stratified by interview language (English/Spanish) and randomized to intervention or EUC. BP reduction was the difference between systolic BP at baseline and 1-year post-discharge. We assessed differences in baseline characteristics and mean BP reduction between trial arms, overall and by race/ethnicity. Linear regressions evaluated mean difference in blood pressure reduction between trial arms, adjusting for characteristics that differed between trial arms at baseline and language of interview. Results: To date, 290 of 552 stroke/TIA patients recruited at baseline (25% white, 32% black, 36% Hispanic) were evaluated at 1 year (n=145 in each arm). Overall, there was a trend toward greater mean BP reduction in the intervention vs. EUC group (9.3 vs. 6.0 mmHg, p=0.259). Mean BP reduction was significantly greater in the intervention vs. EUC group among Hispanics (9.9 vs. -0.7 mmHg, p=0.040). Among Hispanics, after adjusting for interview language, sex, and place of birth, mean BP reduction was 10.9 mmHg greater in the intervention vs. EUC group (p=0.041). Mean BP reduction did not differ significantly between trial arms among non-Hispanics. We are currently gathering information to evaluate the impact of the intervention on secondary stroke incidence. Conclusions: Few behavioral intervention studies in stroke survivors have reported significant differences in vascular risk reduction in the longer term, and fewer have focused on a skills-based approach. Culturally-tailored, skills-based interventions may be more useful than knowledge-focused interventions in achieving sustained vascular risk reduction and addressing race/ethnic disparities in stroke.

Abstract 90: Cost-Benefit Comparison of Inpatient versus Clinical Decision Unit Management of TIA

Introduction: Because TIA increases the risk of subsequent stroke, rapid TIA management is key to stroke prevention. Controversy remains regarding the appropriate site of care for TIA patients. Recent literature shows high variability in care processes, admission rates, timeliness of interventions, cost of care, and outcomes, regardless of site of care. We developed a rapid TIA management process in our Clinical Decision Unit (CDU) to reduce cost and adverse outcomes. TIA patients that present to our ED are admitted to the CDU, but transfer patients with TIA are admitted to the inpatient unit (IPU). Methods: Retrospectively, we identified TIA cases by ICD coding, and reviewed records from 4/1/2012 to 3/31/2016 for patients in the CDU and in the IPU. We compared length of stay (LOS), cost of care, readmission rates, and TIA/stroke recurrence between the two groups. Statistical analysis included Chi-square and Wilcoxon two-sample test for recurrence and readmission rates, and generalized linear modeling and Poisson analysis for LOS and cost analysis. Results: A total of 731 patients presented for TIA management in the study period; 393 in CDU, and 338 in IPU. There was no statistical difference in age or sex between the two groups. Mean LOS (hours) in CDU vs IPU was 15 vs 108 (p&lt;0.001), respectively. Total cost of care in CDU vs IPU was $3,835 vs $11,904 (p&lt;0.001), respectively. Univariate analysis showed no appreciable difference in recurrent TIA or stroke rates; multivariate analysis of stroke recurrence for CDU (1.0%) vs IPU (3.6%) did show a small difference (p=0.024). When factoring in reduction of stroke recurrence, the final cost savings of the CDU program equaled $8,258 per patient. There was no difference in readmission rates between the two groups. Conclusion: Using a rapid TIA management protocol yielded a significantly lower LOS and cost per patient. This may justify an avoidance of inpatient admission for TIA patients.

Abstract WP374: Implementation of the Stroke Transition Discharge Center Improves 30-day Readmission Rate

Background: Stroke patients and their caregivers require formalized education, medications, testing and rehabilitation to assist in prevention of recurrence and of post-stroke complications for optimal outcomes. Objective: The purpose of this program was to evaluate the effect of the Stroke Transition Discharge Center (STDC) on stroke readmission. Methods: The Advanced Practice Nurses (APN) see all stroke and TIA patients one week after discharge from hospital to home or one week after discharge from rehab to home. During the hour encounter, the APN reviews medications, test results, signs and symptoms of stroke, complete education including patient specific risk factors and ensure appropriate follow up. The APN coordinates and facilitates multiple services and disciplines impacting the patient, assuring the most efficient and effective goal-directed activities are provided at the right time and in partnership with all other disciplines providing care. Results: Implementation of the STDC enhances patient outcomes and improves 30-day readmission rates. Prior to our intervention, the readmission rate was 15.3%. After the implementation of the STDC, there was a 61% reduction in 30-day readmission rates to 6%, which is significantly below the hospital system benchmark of 11%. There was an increase in the readmission rate in the first two quarters of 2016 noted. There is an inverse correlation with the number of patients seen in the STDC during the same time period. Further analysis demonstrates that only one readmission in this time period had been seen prior in the STDC. Conclusion: Implementing the Stroke Transition Discharge Center demonstrated a dramatic reduction in 30-day readmission rates. Our data suggests that utilization of the clinic and participation by the patients has a direct and inverse effect on readmissions. Further data will need to be collected to determine if this is a sustained response.

Abstract TMP94: Outcomes in Hospitalized Stroke and TIA Patients with Dementia - A Population-based Study

Background: Dementia prevalence is rising, and will double in the next 20 years. This study sought to understand the prevalence of dementia in hospitalized patients with stroke and TIA, differences in characteristics and impact on outcomes. Methods: Using the Canadian Institute of Health Information (CIHI) Discharge Abstract Database (DAD), all acute stroke and TIA admissions from April 2003 to March 2015 in Canada (excluding Quebec) were analyzed. Concurrent dementia at time of admission was assessed based on hospital diagnostic codes. Characteristics and in-hospital outcomes were compared in patients with vs. without dementia using chi-square and logistic regression. Results: During the observed period 464,741 patients were admitted to hospital for cerebrovascular syndromes (ischemic stroke, intracerebral hemorrhage, subarachnoid hemorrhage (SAH) and TIA). Of those, 29,812 (6.4%) had a concurrent diagnosis of dementia, including 8.4% of patients ≥65 years. People with dementia had older median age (84 vs. 75 years; p&lt;0.01), were more often female (59.6% vs. 49.3%; p&lt;0.01) and more often had Charlson-Deyo comorbidity index ≥ 2 (62.1% v. 38.4%; p&lt;0.01). They were less likely admitted with SAH (1.3% vs. 5.3%; p&lt;0.01) and more likely coded as strokes with unidentified subtype (29.4% vs. 20.8%; p&lt;0.01). Median length of stay (13 vs. 7 days; p&lt;0.01) was longer. Patients with dementia were less likely discharged to another acute care facility (7.6% vs. 14.7%; p&lt;0.01), rehabilitation facility (5.4% vs. 12.0%; p&lt;0.01) or home independently (22.9% 48.9%; p&lt;0.01); other outcomes are shown in the Table. Conclusions: Approximately 1 in 10 hospitalized stroke and TIA patients age ≥65 has coded dementia. Patients with stroke or TIA and dementia have higher mortality, face significantly more dependence after stroke and utilize greater healthcare resources than stroke patients without dementia. Early care planning and coordination are essential to optimize outcomes.

Abstract WP320: Uncertainty: A Key Influence in the Decision to Admit Patients With Transient Ischemic Attack

Introduction: Hospitalization of TIA patients has been shown to improve the timeliness and quality of TIA care yet admission rates for patients presenting with TIA vary considerably across centers. Methods: We sought to identify patient and system level factors linked to the decision to admit a patient with TIA. Trained interviewers conducted face-to-face semi-structured interviews with staff involved in TIA care at diverse Veterans Administration (VA) sites. All transcripts were de-identified and imported into a single NVivo10 project file for data coding and analysis. Results: 70 audiotaped interviews of multidisciplinary clinical staff took place at 14 Veterans Administration Medical Centers (VAMCs). We identified emergent themes and patterns in providers’ decision making. Uncertainty was a key theme in factors that staff reported as an influence in providers’ decisions to admit including: lack of guidance at sites without a facility TIA-specific policy, diagnostic uncertainty related to the TIA event (versus stroke or stroke mimic), general lack of confidence in the ability to complete a timely workup, and specific concerns about patients living a long distance from a VAMC or lacking a support system. Overall, the ABCD 2 score was reported by participants not as a rationale for decisions to admit, but rather for decisions not to admit. Other reported factors related to the decision not to admit included: longer period of time since symptom onset, lack of symptoms, confidence in the ability to get a timely workup as an outpatient, recent evaluation for a prior TIA or stroke event, close proximity of the patient’s residence to a VA facility, strong patient support at home, currently maximized medical management, and availability of observation beds. Conclusions: Issues related to uncertainty were reported as key factors in clinical decisions concerning admittance of patients presenting with TIA. Quality improvement interventions for TIA care may need to take into consideration how factors like uncertainty relate to the TIA admission decision-making process.

Abstract WP246: Probabilistic Linkage of De-identified Prehospital and Hospital Data for Stroke Patients Achieves Similar Match Rates to Manual Linkage

Background: Acute ischemic stroke patients that are recognized by Emergency medical services (EMS) receive expedited care are more likely to receive t-PA. In order to study the continuum of acute stroke care and ensure accurate case ascertainment, prehospital and inpatient medical records must be linked. We tested the feasibility of probabilistic matching to link prehospital EMS data and in-hospital records using data from existing de-identified registries, and compared results to manual linkage. Methods: A registry containing all EMS-transported suspect or confirmed stroke cases in Kent County, Michigan was used to identify subjects discharged from either of two primary stroke centers with a diagnosis of stroke or TIA. The registry contains EMS data obtained through direct query of EMS electronic medical record systems which is linked manually to hospital data using patient identifiers (name, date of birth). For the probabilistic match, de-identified data for EMS suspected stroke transports from the EMS information system (EMSIS) was provided by the county medical control authority. Probabilistic linkage between hospital stroke discharges and EMSIS data was done using LinkPlus software. Age, sex, transport agency, and date of service were used as matching variables. Probabilistic match rates were compared to manual registry match rates among EMS suspect stroke cases using a chi square test. Results: Over a 6-month period in 2015, 172 hospital-confirmed stroke and TIA patients arrived by EMS at the target hospitals. Over the same period, 214 EMS suspect stroke cases were identified from the registry and 199 EMS suspect stroke cases were identified in EMSIS. Probabilistic linkage correctly matched 64.5% (111/172) of confirmed strokes to prehospital records in EMSIS, which was not significantly different from the manual registry match rate of 73.8% (127/172, p=0.24). There were 16 cases in the manual match that were missed by the probabilistic match: 5 (2.9%) due to age mismatch and 11 (6.4%) were missing from the EMSIS data. The remaining non-matched cases represented EMS missed stroke cases. Conclusion: Probabilistic matching of de-identified pre-hospital and hospital data is a feasible approach for the evaluation of prehospital stroke care.

Sequence Analysis of Long-Term Readmissions among High-Impact Users of Cerebrovascular Patients.

Objective Understanding the chronological order of the causes of readmissions may help us assess any repeated chain of events among high-impact users, those with high readmission rate. We aim to perform sequence analysis of administrative data to identify distinct sequences of emergency readmissions among the high-impact users. Methods A retrospective cohort of all cerebrovascular patients identified through national administrative data and followed for 4 years. Results Common discriminating subsequences in chronic high-impact users (n = 2863) of ischaemic stroke (n = 34208) were “urological conditions-chest infection,” “chest infection-urological conditions,” “injury-urological conditions,” “chest infection-ambulatory condition,” and “ambulatory condition-chest infection” (p < 0.01). Among TIA patients (n = 20549), common discriminating (p < 0.01) subsequences among chronic high-impact users were “injury-urological conditions,” “urological conditions-chest infection,” “urological conditions-injury,” “ambulatory condition-urological conditions,” and “ambulatory condition-chest infection.” Among the chronic high-impact group of intracranial haemorrhage (n = 2605) common discriminating subsequences (p < 0.01) were “dementia-injury,” “chest infection-dementia,” “dementia-dementia-injury,” “dementia-urine infection,” and “injury-urine infection.” Conclusion. Although common causes of readmission are the same in different subgroups, the high-impact users had a higher proportion of patients with distinct common sequences of multiple readmissions as identified by the sequence analysis. Most of these causes are potentially preventable and can be avoided in the community. Conclusion Although common causes of readmission are the same in different subgroups, the high-impact users had a higher proportion of patients with distinct common sequences of multiple readmissions as identified by the sequence analysis. Most of these causes are potentially preventable and can be avoided in the community.

Have clinicians adopted the use of brain MRI for patients with TIA and minor stroke?

Use of MRI with diffusion-weighted imaging (DWI) can identify infarcts in 30%-50% of patients with TIA. Previous guidelines have indicated that MRI-DWI is the preferred imaging modality for patients with TIA. We assessed the frequency of MRI utilization and predictors of MRI performance. A review of TIA and minor stroke patients evaluated at Veterans Affairs hospitals was conducted with regard to medical history, use of diagnostic imaging within 2 days of presentation, and in-hospital care variables. Chart abstraction was performed in a subset of hospitals to assess clinical variables not available in the administrative data. A total of 7,889 patients with TIA/minor stroke were included. Overall, 6,694 patients (84.9%) had CT or MRI, with 3,396/6,694 (50.7%) having MRI. Variables that were associated with increased odds of CT performance were age >80 years, prior stroke, history of atrial fibrillation, heart failure, coronary artery disease, anxiety, and low hospital complexity, while blood pressure >140/90 mm Hg and high hospital complexity were associated with increased likelihood of MRI. Diplopia (87% had MRI, p = 0.03), neurologic consultation on the day of presentation (73% had MRI, p < 0.0001), and symptom duration of >6 hours (74% had MRI, p = 0.0009) were associated with MRI performance. Within a national health system, about 40% of patients with TIA/minor stroke had MRI performed within 2 days. Performance of MRI appeared to be influenced by several patient and facility-level variables, suggesting that there has been partial acceptance of the previous guideline that endorsed MRI for patients with TIA.