Left Ventricular Assist Device Cohort Research Articles

Early outcomes in heart transplantation using donation after circulatory death donors in patients bridged with durable left ventricular assist devices

ObjectiveDonation after circulatory death heart transplantation potentially increases donor allografts, especially for patients with lower listing status. We assessed the outcomes of donation after circulatory death heart transplantation in patients bridged with durable left ventricular assist devices. MethodsThe United Network for Organ Sharing database was queried for adult heart transplants using donation after circulatory death donors from 2019 to 2022. Patients were stratified between those with durable left ventricular assist devices and those with intra-aortic balloon pump, inotropic, or no bridging support (control group). Primary outcome was 1-year mortality. Secondary end points were hospital length of stay, stroke, pacemaker implantation, dialysis, and acute rejection before discharge. ResultsA total of 160 left ventricular assist device recipients and 311 control recipients met study inclusion criteria. Recipients bridged with left ventricular assist devices were younger (55 vs 58 years, P < .001) with lower body mass index (28.3 vs 30.3, P < .001), longer waitlist times (112 vs 34 days, P < .001), longer out of body times (5.7 vs 4.6 hours, P < .001), and less frequent normothermic regional perfusion (31% vs 40%, P = .049). Patients with left ventricular assist devices commonly underwent transplantation at United Network for Organ Sharing status 3 and 4 (92%), whereas control patients underwent transplantation at status 2 (27%), status 3 (10%), status 4 (30%), or status 6 (30%). Kaplan–Meier analysis showed no difference in 1-year mortality between groups (P = .34). However, acute rejection was higher in the unadjusted left ventricular assist device cohort (26% vs 13%, P < .001). On multivariable logistic regression, left ventricular assist device was an independent predictor of acute rejection (odds ratio, 2.21, 95% CI, 1.32-3.69, P = .002). ConclusionsDurable left ventricular assist devices may be associated with a higher risk of developing an early inflammatory response in donation after circulatory death heart transplantation; however, 1-year survival was similar between groups.

Severe obesity among patients with left ventricular assist devices

Patients with obesity and advanced heart failure requiring left ventricular assist device (LVAD) support are more likely to experience LVAD complications and may be disproportionately Black and/or female when compared to patients without obesity. Among these patients, obesity may represent a barrier to transplant eligibility and a marker of inequity in heart transplantation and health outcomes in advanced heart failure. To better understand this issue at our institution, we examined our active LVAD cohort and found that almost one-third of all patients had severe obesity with BMI ≥ 35 kg/m2. Patients with LVADs and severe obesity were significantly younger and more likely to self-identify as Black, and numerically more likely to be female. Weight management in this group represents a vital area for improved equity in health outcomes and barriers to heart transplantation. NA.

Occult right ventricular dysfunction and right ventricular-vascular uncoupling in left ventricular assist device recipients

BackgroundCurrent assessments remain insensitive for detecting right heart failure post left ventricular assist device (LVAD). Sensitive pressure-volume loop assessments of right ventricle (RV) contractility may improve our appreciation of post-LVAD RV dysfunction. MethodsThirteen LVAD patients and 20 reference (non-LVAD) subjects underwent comparison of echocardiographic, right heart cath hemodynamic, and pressure-volume loop-derived assessments of RV contractility using end-systolic elastance (Ees), RV afterload by effective arterial elastance (Ea), and RV-pulmonary arterial (RV-PA) coupling (ratio of Ees/Ea). ResultsLVAD patients had lower RV Ees (0.20±0.08 vs. 0.30±0.15 mmHg/ml, p=0.01) and lower RV Ees/Ea (0.37±0.14 vs 1.20±0.54, p<0.001) versus reference subjects. Low RV Ees correlated with reduced RV septal strain, an indicator of septal contractility, in both the entire cohort (r=0.68, p=0.004) as well as the LVAD cohort itself (r=0.78, p=0.02). LVAD recipients with low RV Ees/Ea (below the median value) demonstrated more clinical heart failure (71% vs 17%, p=0.048), driven by an inability to augment RV Ees (0.22±0.11 vs 0.19±0.02 mmHg/ml, p=0.95) to accommodate higher RV Ea (0.82±0.38 vs 0.39±0.08 mmHg/ml, p=0.002). Pulmonary artery pulsatility index (PAPi) best identified low baseline RV Ees/Ea (≤0.35) in LVAD patients (AUC=0.80); during ramp study, change in PAPi also correlated with change in RV Ees/Ea (r=0.58, p=0.04). ConclusionsLVAD patients demonstrate occult intrinsic RV dysfunction. In the setting of excess RV afterload, LVAD patients lack the RV contractile reserve to maintain ventriculo-vascular coupling. Depression in RV contractility may be related to LVAD LV unloading which reduces septal contractility.

Safety and tolerability of sodium-glucose cotransporter-2 inhibitors in bridge-to-transplant patients supported with centrifugal-flow left ventricular assist devices

BackgroundThe safety and tolerability of sodium-glucose cotransporter-2 inhibitors (SGLT2i) in patients with end-stage heart failure supported with left-ventricular-assist-devices (LVADs), irrespective of diabetes mellitus, is not known. MethodsA retrospective analysis of 31 outpatients implanted with LVADs as bridge-to-transplant (BTT) was conducted. Patients with biventricular support, aged under 18 years, who were discharged from the index hospitalisation, or were prescribed SGLT2i prior to their first outpatient clinic were excluded. Patient demographics, laboratory studies, pump haemodynamic and adverse event data was collected. ResultsSixteen (51.6%) of 31 patients were prescribed SGLT2i over median 101.5 days (37.5–190.8). No patients discontinued SGLT2i use or reported attributable adverse symptoms. No significant differences between patients prescribed SGLT2i compared to those SGLT2i-naïve were seen in: [1] renal function; [2] weight; [3] mean arterial pressure. There were numerically lower infection-related (n = 4 vs 7, HR 0.32 (0.08–1.28), p = 0.11) and haemocompatibility-related (n = 3 vs 4, HR 0.52 (0.09–2.83), p = 0.45) adverse events in the SGLT2i group, albeit non-significant. ConclusionsWe found SGLT2i to be safe and well-tolerated in the BTT LVAD cohort with no significant difference in rates of infection or haemocompatibility-related adverse events with SGLT2i use. Larger studies will inform further beneficial effects of SGLT2i prescription in this cohort.

Abstract 15045: Impact of Left Ventricular Assist Device (LVAD) Type on Arrhythmic Outcomes in Patients With Continuous Flow LVADs

Introduction: Cardiac arrhythmias are common in continuous flow left ventricular assist device (LVAD) recipients. The impact of axial vs. intrapericardial centrifugal LVAD pumps on arrhythmia incidence and associated clinical outcomes is unclear. Hypothesis: This multicenter study evaluated the impact of LVAD type (axial vs. centrifugal) on incidence of atrial and ventricular arrhythmias, ICD shocks and mortality in LVAD patients. Methods: Analysis was done on 536 patients who underwent LVAD implantation at 5 US centers from 2008 to 2016. The groups were divided based on their LVAD type (axial - HeartMate II [HMII, n=433] vs. centrifugal - HeartWare (HW, n=103). Baseline characteristics as well as incidence of post-LVAD atrial arrhythmias (PL-AA), ventricular arrhythmias (PL-VA) and ICD shocks were analyzed in these groups. Multivariable Cox Regression analysis was used to identify predictors of survival. Results: Of 536 patients, 433 had HMII axial LVAD and 103 had HW centrifugal VAD implant. At baseline, HMII group had more males, higher proportion of CRT-D and higher prevalence of AA (Table 1A). Left ventricular dimensions were similar between groups. During a median follow-up of 537 days of LVAD support, incidence of PL-VA and ICD shocks were significantly higher in the HM2 group compared to HW group whereas incidence of PL-AA was not significantly different (Table 1A). In multivariable Cox Regression analysis, LVAD indication was the only variable that predicted survival (Table 1B). Type of LVAD (axial vs. centrifugal) was not associated with survival (HMII vs. HW - HR 1.04, P=0.48). Conclusions: In this multi-center continuous flow LVAD cohort, axial HM2 VAD patients had a higher incidence of PL-VA and ICD shocks. Type of LVAD (axial vs. centrifugal) was not associated with survival.

Established Clinical Prediction Rules for Bleeding Had Mediocre Discrimination in Left Ventricular Assist Device Recipients.

Left ventricular assist devices (LVAD) reduce mortality in patients with end-stage heart failure, but LVAD management is frequently complicated by bleeding. Bleeding prediction post-LVAD implantation is challenging as prediction rules for hemorrhage have not been rigorously studied in this population. We aimed to validate clinical prediction rules for bleeding, derived in the atrial fibrillation and venous thromboembolism populations, in an LVAD cohort. This was a retrospective cohort study of LVAD recipients at an academic center. The primary end-point was time to gastrointestinal bleed or intracranial hemorrhage after implant; the secondary end-point was time to any major hemorrhage after hospital discharge. Four hundred and eighteen patients received an LVAD (135 HeartMate II, 125 HeartMate 3, 158 HVAD) between November 2009 and January 2019. The primary end-point occurred in 169 (40.4%) patients with C -statistics ranging 0.55-0.58 (standard deviation [SD] 0.02 for all models). The secondary end-point occurred in 167 (40.0%) patients with C -statistics ranging 0.53-0.58 (SD 0.02 for all models). Modifying the age and liver function thresholds increased the C -statistic range to 0.56-0.60 for the primary and secondary end-points. In a sensitivity analysis of HeartMate 3 patients, prediction rules performed similarly. Existing prediction rules for major bleeding had mediocre discrimination in an LVAD cohort.

Predictive capabilities of the European registry for patients with mechanical circulatory support right-sided heart failure risk score after left ventricular assist device implantation

The prediction of right heart failure (RHF) after left ventricular assist device (LVAD) implantation remains a challenge. Recently, risk scores were derived from analysis of the European Registry for Patients with Mechanical Circulatory Support (EUROMACS) data, the EUROMACS-RHF, and the modified postoperative EUROMACS-RHF. The authors assessed the performance characteristics of these 2 risk score formulations in a continuous-flow LVAD cohort at their institution. A retrospective, observational study. At a tertiary-care academic medical center. Adult patients who underwent durable LVAD implantation between 2015 and 2018. None MEASUREMENTS AND MAIN RESULTS: Early post-LVAD RHF was defined as follows: (1) need for right ventricular assist device, or (2) inotropic or inhaled pulmonary vasodilator support for ≥14 postoperative days. The authors used logistic regression and examined receiver operating characteristic (ROC) curves to evaluate the ability of the 2 risk scores to distinguish between outcome groups. A total of 207 patients met the inclusion criteria. Of the patients, 16% developed RHF (33/207). The EUROMACS-RHF score was not predictive of RHF in the authors' cohort (odds ratio [OR] 1.25; 95% CI [0.99-1.60]; p=0.06), but the postoperative EUROMACS-RHF CPB score was significantly associated (OR 1.38; 95% CI [1.03-1.89]; p=0.03). The scores had similar ROC curves, with weak discriminatory performance: 0.601 (95% CI [0.509-0.692]) and 0.599 (95% CI [0.505-0.693]) for EUROMACS-RHF and postoperative EUROMACS-RHF, respectively. In the authors' single-center retrospective analysis, the EUROMACS-RHF risk score did not predict early RHF. An optimized risk score for the prediction of RHF after LVAD implantation remains an urgent unmet need.

Evaluation of a novel virtual care platform for remote monitoring of LVAD patients.

The aim of this study was to evaluate a novel virtual care platform created for use in Left Ventricular Assist Device (LVAD) patients. The platform included a daily log of LVAD parameters and medication adherence, two-way messaging with providers, and educational resources. To test the feasibility of this application, we recruited 25 patients between 2017 and 2019 and followed them for 6 months post discharge. Feedback concerning the platform was very positive with an average score of 4.5 ± 0.6 (out of 5) on usability and/or satisfaction and 8.1 ± 1.8 (out of 10) on likelihood to recommend the platform. In addition, our platform was well utilized with median (IQR) engagement rates of 87 (53,100)% at 30 days and 73 (49,95)% overall. We found that patients using the platform attended significantly less outpatient visits at the 6 month mark, however there was no difference in 30-day readmission rates compared to the overall LVAD cohort.

Validation Of Clinical Prediction Rules For Bleeding In Patients With A Left Ventricular Assist Device

<h3>Introduction</h3> Left ventricular assist devices (LVADs) reduce mortality and morbidity in patients with end-stage heart failure. Patients with LVADs require warfarin therapy, and bleeding occurs and complicates therapy in nearly half of these recipients. Predicting which patients will bleed after LVAD implant is challenging, and prediction rules for major bleeding have not been rigorously studied in this population. We aimed to validate previously described clinical prediction rules for bleeding in an LVAD cohort. <h3>Methods</h3> This was a single-center, retrospective cohort study of patients who received an LVAD at Barnes-Jewish Hospital. Data used to tabulate risk scores and adjudicate outcomes were collected through chart review. The primary clinical endpoint was time to major gastrointestinal bleed or intracranial hemorrhage after implant. The secondary endpoint was time to any major bleed after hospital discharge. <h3>Results</h3> A total of 418 patients received an LVAD (135 HeartMate II, 125 HeartMate 3, 158 HVAD) between November 2009-January 2019. The primary endpoint occurred in 168 (40.1%) patients. C-statistics for the primary endpoint ranged 0.53-0.58 (P<0.05 for HAS-BLED, HEMORR₂HAGES, ATRIA, Outpatient Bleeding Risk Index, and VTE-BLEED). The secondary endpoint occurred in 167 (40.0%) patients, and C-statistics ranged 0.52-0.58 (P<0.05 for HAS-BLED, Outpatient Bleeding Risk Index, and VTE-BLEED). After modifying the age threshold in each prediction rule to 59 years (the median age of the cohort), C-statistics ranged 0.55-0.61 for the primary and secondary endpoints. In a subgroup analysis of HeartMate 3 patients, prediction rules performed similarly. <h3>Conclusion</h3> Existing clinical prediction rules for major bleeding, previously derived in other anticoagulated populations, had mediocre discrimination in an LVAD cohort.

Stroke Risk in the Contemporary Era of Left Ventricular Assist Device Support

<h3>Purpose</h3> The HeartMate 3 left ventricular assist device (LVAD) has lower stroke rates compared to the HeartMate 2 in a clinical trial setting. Here we report real world stroke rates in patients implanted with HeartMate 2 and HeartMate 3 LVADs. <h3>Methods</h3> Data from a single center, first time continuous-flow LVAD cohort was utilized for this analysis (n=549). Patients with complete stroke data implanted with HeartMate2 (n=151) or HeartMate3(n=167) were included (n=318). Time to first stroke and stroke type were recorded. Freedom from all cause stroke by device type was estimated using the Kaplan Meir method and compared with the log rank test. To assess the adjusted difference in the rate of stroke by pump type, a multivariable cox regression was performed <h3>Results</h3> The mean age of the study cohort was 59 +/- 14 years, 83 % (265/318) were men, 63 % (197/318) were destination therapy and 31 % (97/318) were INTERMACS profiles 1 and 2. Freedom from all cause stroke to 1 year of LVAD support was similar between pumps (HeartMate 3: 88 % vs. HeartMate 2: 89 %, p = 0.76, adjusted HR 1.12, 95% CI 0.56-2.26, p=0.74), however the odds of thrombotic stroke in the first 60 days post-implantation was higher in the HeartMate 3 recipients (OR 2.5, 95 % CI 0 .86- 7.12, p=0.093). Ninety-five percent (17/18) of stroke events in HeartMate 3 recipients in the first 60 days post-implantation were ischemic in etiology. <h3>Conclusion</h3> The wider gaps within the HeartMate 3 may increase the risk of early post-operative embolic events. Special attention to prevent any material ingestion into the pump during HeartMate 3 implant is likely important and may reduce strokes in the early post-operative period.

Sex-Based Outcomes After Implantation of a Fully Magnetically Levitated Left Ventricular Assist Device

<h3>Purpose</h3> Left ventricular assist devices (LVAD) remain underutilized in females and therefore poorly studied in relation to biological sex. Whether outcomes vary by sex after implantation of a fully magnetically levitated LVAD implantation remains uncertain. <h3>Methods</h3> In this analysis, MOMENTUM 3 study data was utilized (pivotal randomized clinical trial and continued access protocol) and adjusted for age (>65 years), body mass index (>30 kg/m²), race, ischemic cardiomyopathy, INTERMACS profile (>2), history of stroke or diabetes, bilirubin, albumin, and estimated GFR. Survival free of disabling stroke or reoperation to replace or remove a malfunctioning device at 2 years was compared by sex (primary endpoint). Overall survival, major adverse events (calculated as events per 100 patient-years), and quality of life (QOL) using EQ-5D-5L visual analogue scale (VAS) scores were also compared. <h3>Results</h3> Of 2,200 HeartMate 3^TM LVAD patients, 448 (20.4%) were female and 1,752 (79.6%) were male. Relative to males, females implanted with HeartMate 3 were younger, more likely to be a Black person and have a non-ischemic cardiomyopathy. There was no difference in the primary endpoint (female: 81.0% vs. male: 77.4%; HR 0.98 [0.76-1.25], p=0.84). Overall survival at 2 years was similar (female 83.9% vs. male: 81.8%; HR 1.08 [0.82-1.41], p=0.60 (Figure 1A). Females were at higher risk of adverse events, driven by stroke (8.3 vs. 6.4; p=0.011), bleeding (77.4 vs. 66.1; p<0.001), and infection (85.7 vs. 72.0; p=0.011), however, males had more arrhythmia (32.4 vs 27.2; p=0.042) (Figure 1B). QOL measurement gains were similar. <h3>Conclusion</h3> Females have similar survival as males in this contemporary LVAD cohort, although major adverse events are increased including stroke, bleeding, and infection. Further work is needed to understand disparity by sex in device implantation, mechanisms of adverse events, and response to medical management.

External assessment of the EUROMACS right-sided heart failure risk score

The EUROMACS Right-Sided Heart Failure Risk Score was developed to predict right ventricular failure (RVF) after left ventricular assist device (LVAD) placement. The predictive ability of the EUROMACS score has not been tested in other cohorts. We performed a single center analysis of a continuous-flow (CF) LVAD cohort (n = 254) where we calculated EUROMACS risk scores and assessed for right ventricular heart failure after LVAD implantation. Thirty-nine percent of patients (100/254) had post-operative RVF, of which 9% (23/254) required prolonged inotropic support and 5% (12/254) required RVAD placement. For patients who developed RVF after LVAD implantation, there was a 45% increase in the hazards of death on LVAD support (HR 1.45, 95% CI 0.98–2.2, p = 0.066). Two variables in the EUROMACS score (Hemoglobin and Right Atrial Pressure to Pulmonary Capillary Wedge Pressure ratio) were not predictive of RVF in our cohort. Overall, the EUROMACS score had poor external discrimination in our cohort with area under the curve of 58% (95% CI 52–66%). Further work is necessary to enhance our ability to predict RVF after LVAD implantation.

Moderate acceptance of COVID-19 vaccination in patients pre- and post-heart transplantation: Experiences from a German Transplant Centre.

Introduction and objectivesPatients awaiting heart transplantation (HTx) are at increased risk developing severe coronavirus disease 2019 (COVID‐19). Patients supported by a left ventricular assist device (LVAD) face additional risks due to coagulopathies during COVID‐19. Following HTx, elevated risk factors for severe COVID‐19 persist due to chronic immunosuppression and frequent comorbidities. Taken together, COVID‐19 vaccination is of critical importance in all three patient cohorts. Here, we report our experience to deliver COVID‐19 vaccination in a German transplant center.Methods and resultsWe screened 211 patients for contraindications and offered the remaining 186 eligible patients COVID‐19 vaccination. Of those, 133 patients (71%) accepted the offer and were vaccinated. Acceptance of vaccination differed between HTx recipients (84 of 113, 74%), patients on the waiting list (34 of 47, 72%), and patients with LVAD support (28 of 50, 56%). The LVAD cohort demonstrated lower acceptance levels for vaccination compared to HTx recipients and patients awaiting HTx (74% vs. 56%; p = 0.028).ConclusionWe demonstrate for the first time only moderate acceptance levels of COVID‐19 vaccination in HTx recipients and candidates on the waiting list compared to general population, despite perceived high‐risk for severe disease. Additionally, those supported by LVAD have even lower adherence. Efforts may need to be made to increase acceptance in this vulnerable as well as cost‐intensive patient cohort.

Utilization of Left Ventricular Assist Device for Congestive Heart Failure: Inputs on Demographic and Hospital Characterization From Nationwide Inpatient Sample.

ObjectivesThe first goal of the study is to provide a descriptive overview of the utilization of left ventricular assist device (LVAD) for the treatment of congestive heart failure (CHF) and determine the rates of LVAD use stratified by patients’ demographic and hospitals’ characteristics in the United States. Next, is to measure the hospitalization outcomes of length of stay (LOS) and cost in inpatients managed with LVAD.MethodsWe conducted a cross-sectional study using the nationwide inpatient sample and included 184,115 patients (age ≥65 years) with a primary discharge diagnosis of hypertensive and non-hypertensive CHF and was further classified by inpatients who were managed with LVAD. We compared the distributions of demographic and hospital characteristics in CHF inpatients with versus without LVAD by performing Pearson’s chi-square test for categorical variables, and independent sample t-test for continuous variables.ResultsThe inpatient utilization of LVAD was 0.93% (1690 out of 184,115) in CHF patients. The LVAD cohort were younger compared to non-LVAD group (mean age, 69.9 years vs. 79.4 years). The utilization rate of LVAD was also almost four times higher in males (1.50%) compared to females (0.36%). Although whites (78.5%) accounted for majority of LVAD recipients, the rate of LVAD utilization was highest in blacks (1.04%) and lowest in Hispanics (0.58%) with whites having utilization rate of 0.89%. Medicare was the dominant primary payer to cover the LVAD inpatients (91.1%), though the rate of LVAD utilization is highest in private (2.22%) and lowest in those covered by public insurance (medicaid/medicare). CHF patients in public hospitals (1.79%) were more than twice more likely to receive LVAD than in private hospitals (0.83%) due to higher utilization rate. LVAD utilization rate was approximately 55 times higher in teaching hospitals (1.67%) compared to non-teaching hospitals (0.03%), and 20 times higher in large bed hospitals (1.41%) compared to small bed-size hospitals (0.07%). CHF patients that received LVAD had a significantly longer LOS (34.6 days vs 9.8 days) and higher inpatient treatment costs ($802,118 vs. $86,302) compared to non-LVAD group.ConclusionThe inpatient utilization of LVAD was in CHF patients is higher in males, blacks and private health insurance beneficiaries. In terms of hospital characteristics, the utilization of LVAD for CHF management was higher in large bed sized, and public type and teaching hospitals compared to their counterparts. This data will allow us to devise strategies to improve LVAD utilization and increase its outreach for heart failure patients, especially those on the transplant waiting list. Despite its effectiveness, aggressive usage of LVAD is restricted due to cost-effectiveness and lack of technical confidence among medical professional due to complications.

Left Ventricular Assist Device Outcomes in Non English Speaking Patients

Introduction Non-English speaking (NES) status has been identified as a risk factor for adverse outcomes in patients with cardiovascular disease. Given the complexity of left ventricular assist device (LVAD) care and the need for frequent provider/patient interactions, we aimed to review outcomes of NES LVAD recipients in a single center LVAD cohort. Methods The analysis included all adult patients who underwent first time, continuous flow LVAD implementation at the University of Minnesota Medical Center from June 2005 to July 2019 (n=413). Patients were identified as NES if they identified English as there second language regardless of interpreter use. To assess the impact of NES on post LVAD outcomes, 1-year readmissions and 2-year survival was compared between NES and English speaking LVAD recipients. Results The study cohort included 13 NES (3%) and 400 (97%) English speaking patients. Six of the NES patients (46%) needed an interpreter during clinical interactions. Detailed baseline characteristics and post LVAD complications of the NES cohort are presented (table). Between English Speaking vs. NES LVAD recipients, no statistically significant differences were detected between age (Mean [±SD]) (58 [±14] vs 56 [±15], P=0.65), male sex (80% vs 92%, P=0.28) or bridge to transplant (BTT) status (59% vs 54%, P=0.69). Observed complications among the NES patients over a median (IQR) follow up time of 348 (202, 647) days were the following; driveline infection: 6 (46%), GI bleed: 4 (30%), stroke: 2 (15%), pump thrombosis: 1(8%), and device replacement for driveline malfunction: 1 (8%). No statistically significant differences were detected between 1-year readmissions between English and NES LVAD patients, (2 [IQR 1, 3] vs 1 [IQR 0.5, 4], P=0.86) or 2-year survival (77% vs. 84%, P=0.89). Conclusion Non English Speaking LVAD recipients had a similar survival compared to the larger LVAD cohort in this single center analysis, however this sample size was small. High rates of driveline infections were observed among NES patients. Larger data will be needed to confirm these observations with a higher degree of confidence.

Optimal cannula positioning of HeartMate 3 left ventricular assist device.

Cannula position in HeartMate II and HeartWare left ventricular assist devices (LVADs) is associated with clinical outcome. This study aimed to investigate the clinical implication of the device positioning in HeartMate 3 LVAD cohort. Consecutive patients who underwent HeartMate 3 LVAD implantation were followed for one year from index discharge. At index discharge, chest X-ray parameters were measured: (a) cannula coronal angle, (b) height of pump bottom, (c) cannula sagittal angle, and (d) cannula lumen area. The association of each measurement of cannula position with one-year clinical outcomes was investigated. Sixty-four HeartMate 3 LVAD patients (58 years old, 64% male) were enrolled. In the multivariable Cox regression model, the cannula coronal angle was a significant predictor of death or heart failure readmission (hazard ratio 1.27 [1.01-1.60], P = .045). Patients with a cannula coronal angle ≤28° had lower central venous pressure (P = .030), lower pulmonary capillary wedge pressure (P = .027), and smaller left ventricular size (P = .019) compared to those with the angle >28°. Right ventricular size and parameters of right ventricular function were also better in the narrow angle group, as was one-year cumulative incidence of death or heart failure readmission (10% vs. 50%, P = .008). Narrow cannula coronal angle in patients with HeartMate 3 LVADs was associated with improved cardiac unloading and lower incidence of death or heart failure readmission. Larger studies to confirm the implication of optimal device positioning are warranted.

High Right Ventricular Afterload Is Associated with Impaired Exercise Tolerance in Patients with Left Ventricular Assist Devices.

Patients with left ventricular assist device (LVAD) have poor exercise tolerance. We aimed to characterize relationship between right ventricular (RV) afterload and exercise capacity, RV reserve, and adaptation to load. Twelve well-compensated LVAD subjects underwent right heart catheterization at rest and during symptom-limited exercise. Cardiopulmonary exercise tests were also performed. Hemodynamics were compared with age- and sex-matched subjects with pulmonary arterial hypertension (PAH) and normal non-athletes. Hemodynamic changes were expressed as Δ(exercise - rest). At rest, LVAD subjects had normal biventricular pressures and cardiac output (CO). On exercise, despite similar increases in pulmonary artery wedge pressure (PAWP) between three groups, RV afterload increased only in LVAD cohort (pulmonary elastance [ΔEa] LVAD: 0.4, PAH: 0.1, normal: 0.1 mmHg/ml, p = 0.0024). This afterload increase coincided with the largest rise in right atrial pressure (RAP), lowest change in RV stroke work index, and smallest CO augmentation (ΔCO LVAD: 1.5, PAH: 4.3, normal: 5.7 L/min, p = 0.0014). Peak VO2 negatively correlated with RV afterload (Ea) (r = -0.8, p = 0.0101), while VE/VCO2 slope had the inverse correlation. During exercise, pulmonary artery pulsatility index worsened while RAP:PAWP ratio was unchanged in LVAD subjects. Well-compensated LVAD patients had poor RV reserve and adaptation to load on exercise compared with PAH and normal subjects.

Intraventricular Flow Patterns in Patients Treated with Left Ventricular Assist Devices.

The success of left ventricular assist device (LVAD) therapy is hampered by complications such as thrombosis and bleeding. Understanding blood flow interactions between the heart and the LVAD might help optimize treatment and decrease complication rates. We hypothesized that LVADs modify shear stresses and blood transit in the left ventricle (LV) by changing flow patterns and that these changes can be characterized using 2D echo color Doppler velocimetry (echo-CDV). We used echo-CDV and custom postprocessing methods to map blood flow inside the LV in patients with ongoing LVAD support (Heartmate II, N = 7). We compared it to healthy controls (N = 20) and patients with dilated cardiomyopathy (DCM, N = 20). We also analyzed intraventricular flow changes during LVAD ramp tests (baseline ± 400 rpm). LVAD support reversed the increase in blood stasis associated with DCM, but it did not reduce intraventricular shear exposure. Within the narrow range studied, the ventricular flow was mostly insensitive to changes in pump speed. Patients with significant aortic insufficiency showed abnormalities in blood stasis and shear indices. Overall, this study suggests that noninvasive flow imaging could potentially be used in combination with standard clinical methods for adjusting LVAD settings to optimize flow transport and minimize stasis on an individual basis.

HLA Allosensitization in Patients on Continuous Flow LVAD Support: Are Patients at Increased Risk?

Allosensitization poses a challenge in identifying appropriate donors for patients (pts) awaiting cardiac transplantation. Continuous flow left ventricular assist device (LVAD) can induce significant allosensitization to human leucocyte antigens (HLA). With advances in surgical approaches and improved LVAD hemocompatibility, the prevalence of allosensitization is not well studied. We evaluated the development of allosensitization in a contemporary LVAD cohort including centrifugal and axial LVADs. In consecutive pts who underwent LVAD in a single center from 2014 to 2018, we examined HLA immune status prior to LVAD and at time of transplant if less than one year or up to one year of LVAD support. Serum alloantibodies were detected with single-antigen beads using a Luminex platform. HLA allosensitization was defined as having a calculated panel reactive antibody (cPRA) >10%. LVAD-associated allosensitization was defined as having a cPRA >10% and cPRA <10% before LVAD. A total of 50 pts who underwent LVAD implantation as bridge to transplant had available cPRA prior to and after LVAD implantation. Mean follow up was 268±91 days. Mean age was 53±13 years, and 26% were female. 18 pts (36%) had centrifugal LVAD. At 1 year, 28 pts (56%) were transplanted, 18 pts (36%) remained on LVAD support, and 4 pts (8%) expired. Of the 50 patients, 14% (n=7) had PRA over 10%. Though the proportion of patients with allosensitization after LVAD increased to 24%, this was not statistically significant (Fig 1A&B). Eight pts had LVAD-associated allosensitization, and in this group, type of device (centrifugal vs axial) was not associated with allosensitization. In our single-center, contemporary cohort, allosensitization before LVAD was not common. LVAD associated allosensitization occurred in about one-fifth of patients.

Utilization and outcomes in biventricular assist device support in pediatrics

ObjectivePatients with biventricular assist devices (BiVADs) have worse outcomes than those with left ventricular assist devices (LVADs). It is unclear whether these outcomes are due to device selection or patient factors. We used propensity score matching to reduce patient heterogeneity and compare outcomes in pediatric patients supported with BiVADs with a similar LVAD cohort. MethodsThe Pedimacs registry was queried for patients who were supported with BiVAD or LVAD. Patients were analyzed by BiVAD or LVAD at primary implant and the 2 groups were compared before and after using propensity score matching. ResultsOf 363 patients who met inclusion criteria, 63 (17%) underwent primary BiVAD support. After propensity score matching, differences between cohorts were reduced. Six months after implant, in the BiVAD cohort (LVAD cohort) 52.5% (42.5%) had been transplanted; 32.5% (40%) were alive with device, and 15% (10%) had died. Survival was similar between cohorts (P = .31, log-rank), but patients with BiVADs were more likely to experience a major adverse event in the form of bleeding (P = .04, log-rank). At 1 week and 1 and 3 months' postimplant, the percentage of patients on mechanical ventilation, on dialysis, or with elevated bilirubin was similar between the 2 groups. ConclusionsWhen propensity scores were used to reduce differences in patient characteristics, there were no differences in survival but more major adverse events in the patients with BiVADs, particularly bleeding. Differences in unmatched patient outcomes between LVAD and BiVAD cohorts likely represent differences in severity of illness rather than mode of support.