Surgically implanted endovascular, microaxial left ventricular assist device: A single institution study

Objective

The Impella 5.5 (Abiomed, Inc), a surgically implanted endovascular microaxial left ventricular assist device, is increasingly used worldwide and there have been more than 10,000 implants. The purpose of this study is to describe a large-volume, single-center experience with the use of the Impella 5.5.

Methods

Data were obtained retrospectively from patients supported with the Impella 5.5 implanted at our institution from May 1, 2020, to December 31, 2022. Demographic, operative, and postoperative outcomes for each group are described. Results are reported in median (interquartile range) or n (%). The entire cohort was divided into 5 main groups based on the intention to treat at the time of the Impella 5.5 implantation: (1) patients who had a planned Impella 5.5 implanted at the time of high-risk cardiac surgery; (2) patients with cardiogenic shock; (3) patients bridged to a durable left ventricular assist device; (4) patients bridged to transplant; and (5) patients with postcardiotomy shock who received an unplanned Impella 5.5 implant.

Results

A total of 126 patients were supported with the Impella 5.5. Overall survival to device explant was 76.2%, with 67.5% surviving to discharge. Midterm survival was assessed with a median follow-up time of 318 days and demonstrated an overall survival of 60.3% and a median of 650 days (549-752).

Conclusions

Outcomes after using the Impella 5.5 are variable depending on the indication of use. Patient selection may be of utmost importance and requires further experience with this device to determine who will benefit from insertion.

Characterization of de novo malignancy after orthotopic heart transplantation: single-centre outcomes over 20 years

OBJECTIVES

Malignancy is the leading cause of late mortality after orthotopic heart transplantation (OHT), and the burden of post-transplantation cancer is expected to rise in proportion to increased case volume following the 2018 heart allocation score change. In this report, we evaluated factors associated with de novo malignancy after OHT with a focus on skin and solid organ cancers.

METHODS

Patients who underwent OHT at our institution between 1999 and 2018 were retrospectively reviewed (n = 488). Terminal outcomes of death and development of skin and/or solid organ malignancy were assessed as competing risks. Fine-Gray subdistribution hazards regression was used to evaluate the association between perioperative patient and donor characteristics and late-term malignancy outcomes.

RESULTS

By 1, 5 and 10 years, an estimated 2%, 17% and 27% of patients developed skin malignancy, while 1%, 5% and 12% of patients developed solid organ malignancy. On multivariable Fine-Gray regression, age [1.05 (1.03-1.08); P < 0.001], government payer insurance [1.77 (1.20-2.59); P = 0.006], family history of malignancy [1.66 (1.15-2.38); P = 0.007] and metformin use [1.73 (1.15-2.59); P = 0.008] were associated with increased risk of melanoma and basal or squamous cell carcinoma. Age [1.08 (1.04-1.12); P < 0.001] and family history of malignancy [2.55 (1.43-4.56); P = 0.002] were associated with an increased risk of solid organ cancer, most commonly prostate and lung cancer.

CONCLUSIONS

Vigilant cancer and immunosuppression surveillance is warranted in OHT recipients at late-term follow-up. The cumulative incidence of skin and solid organ malignancies increases temporally after transplantation, and key risk factors for the development of post-OHT malignancy warrant identification and routine monitoring.

Rare Variant Genetics and Dilated Cardiomyopathy Severity: The DCM Precision Medicine Study

BACKGROUND

Dilated cardiomyopathy (DCM) can lead to advanced disease, defined herein as necessitating a durable left ventricular assist device or a heart transplant (LVAD/HT). DCM is known to have a genetic basis, but the association of rare variant genetics with advanced DCM has not been studied.

METHODS

We analyzed clinical and genetic sequence data from patients enrolled between 2016 and 2021 in the US multisite DCM Precision Medicine Study, which was a geographically diverse, multiracial, multiethnic cohort. Clinical evaluation included standardized patient interview and medical record query forms. DCM severity was classified into 3 groups: patients with advanced disease with LVAD/HT; patients with an implantable cardioverter defibrillator (ICD) only; or patients with no ICD or LVAD/HT. Rare variants in 36 DCM genes were classified as pathogenic or likely pathogenic or variants of uncertain significance. Confounding factors we considered included demographic characteristics, lifestyle factors, access to care, DCM duration, and comorbidities. Crude and adjusted associations between DCM severity and rare variant genetic findings were assessed using multinomial models with generalized logit link.

RESULTS

Patients' mean (SD) age was 51.9 (13.6) years; 42% were of African ancestry, 56% were of European ancestry, and 44% were female. Of 1198 patients, 347 had LVAD/HT, 511 had an ICD, and 340 had no LVAD/HT or ICD. The percentage of patients with pathogenic or likely pathogenic variants was 26.2%, 15.9%, and 15.0% for those with LVAD/HT, ICD only, or neither, respectively. After controlling for sociodemographic characteristics and comorbidities, patients with DCM with LVAD/HT were more likely than those without LVAD/HT or ICD to have DCM-related pathogenic or likely pathogenic rare variants (odds ratio, 2.3 [95% CI, 1.5-3.6]). The association did not differ by ancestry. Rare variant genetic findings were similar between patients with DCM with an ICD and those without LVAD/HT or ICD.

CONCLUSIONS

Advanced DCM was associated with higher odds of rare variants in DCM genes adjudicated as pathogenic or likely pathogenic, compared with individuals with less severe DCM. This finding may help assess the risk of outcomes in management of patients with DCM and their at-risk family members.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT03037632.

Genetic Architecture of Dilated Cardiomyopathy in Individuals of African and European Ancestry

Importance

Black patients with dilated cardiomyopathy (DCM) have increased familial risk and worse outcomes than White patients, but most DCM genetic data are from White patients.

Objective

To compare the rare variant genetic architecture of DCM by genomic ancestry within a diverse population of patients with DCM.

Design

Cross-sectional study enrolling patients with DCM who self-identified as non-Hispanic Black, Hispanic, or non-Hispanic White from June 7, 2016, to March 15, 2020, at 25 US advanced heart failure programs. Variants in 36 DCM genes were adjudicated as pathogenic, likely pathogenic, or of uncertain significance.

Exposure

Presence of DCM.

Main Outcomes and Measures

Variants in DCM genes classified as pathogenic/likely pathogenic/uncertain significance and clinically actionable (pathogenic/likely pathogenic).

Results

A total of 505, 667, and 26 patients with DCM of predominantly African, European, or Native American genomic ancestry, respectively, were included. Compared with patients of European ancestry, a lower percentage of patients of African ancestry had clinically actionable variants (8.2% [95% CI, 5.2%-11.1%] vs 25.5% [95% CI, 21.3%-29.6%]), reflecting the lower odds of a clinically actionable variant for those with any pathogenic variant/likely pathogenic variant/variant of uncertain significance (odds ratio, 0.25 [95% CI, 0.17-0.37]). On average, patients of African ancestry had fewer clinically actionable variants in TTN (difference, -0.09 [95% CI, -0.14 to -0.05]) and other genes with predicted loss of function as a disease-causing mechanism (difference, -0.06 [95% CI, -0.11 to -0.02]). However, the number of pathogenic variants/likely pathogenic variants/variants of uncertain significance was more comparable between ancestry groups (difference, -0.07 [95% CI, -0.22 to 0.09]) due to a larger number of non-TTN non-predicted loss of function variants of uncertain significance, mostly missense, in patients of African ancestry (difference, 0.15 [95% CI, 0.00-0.30]). Published clinical case-based evidence supporting pathogenicity was less available for variants found only in patients of African ancestry (P < .001).

Conclusion and Relevance

Patients of African ancestry with DCM were less likely to have clinically actionable variants in DCM genes than those of European ancestry due to differences in genetic architecture and a lack of representation of African ancestry in clinical data sets.

Screening for Dilated Cardiomyopathy in At-Risk First-Degree Relatives

BACKGROUND

Cardiovascular screening is recommended for first-degree relatives (FDRs) of patients with dilated cardiomyopathy (DCM), but the yield of FDR screening is uncertain for DCM patients without known familial DCM, for non-White FDRs, or for DCM partial phenotypes of left ventricular enlargement (LVE) or left ventricular systolic dysfunction (LVSD).

OBJECTIVES

This study examined the yield of clinical screening among reportedly unaffected FDRs of DCM patients.

METHODS

Adult FDRs of DCM patients at 25 sites completed screening echocardiograms and ECGs. Mixed models accounting for site heterogeneity and intrafamilial correlation were used to compare screen-based percentages of DCM, LVSD, or LVE by FDR demographics, cardiovascular risk factors, and proband genetics results.

RESULTS

A total of 1,365 FDRs were included, with a mean age of 44.8 ± 16.9 years, 27.5% non-Hispanic Black, 9.8% Hispanic, and 61.7% women. Among screened FDRs, 14.1% had new diagnoses of DCM (2.1%), LVSD (3.6%), or LVE (8.4%). The percentage of FDRs with new diagnoses was higher for those aged 45 to 64 years than 18 to 44 years. The age-adjusted percentage of any finding was higher among FDRs with hypertension and obesity but did not differ statistically by race and ethnicity (16.2% for Hispanic, 15.2% for non-Hispanic Black, and 13.1% for non-Hispanic White) or sex (14.6% for women and 12.8% for men). FDRs whose probands carried clinically reportable variants were more likely to be identified with DCM.

CONCLUSIONS

Cardiovascular screening identified new DCM-related findings among 1 in 7 reportedly unaffected FDRs regardless of race and ethnicity, underscoring the value of clinical screening in all FDRs.

Effectiveness of the Family Heart Talk Communication Tool in Improving Family Member Screening for Dilated Cardiomyopathy: Results of a Randomized Trial

BACKGROUND

Managing disease risk among first-degree relatives of probands diagnosed with a heritable disease is central to precision medicine. A critical component is often clinical screening, which is particularly important for conditions like dilated cardiomyopathy (DCM) that remain asymptomatic until severe disease develops. Nonetheless, probands are frequently ill-equipped to disseminate genetic risk information that motivates at-risk relatives to complete recommended clinical screening. An easily implemented remedy for this key issue has been elusive.

METHODS

The DCM Precision Medicine Study developed Family Heart Talk, a booklet designed to help probands with DCM communicate genetic risk and the need for cardiovascular screening to their relatives. The effectiveness of the Family Heart Talk booklet in increasing cardiovascular clinical screening uptake among first-degree relatives was assessed in a multicenter, open-label, cluster-randomized, controlled trial. The primary outcome measured in eligible first-degree relatives was completion of screening initiated within 12 months after proband enrollment. Because probands randomized to the intervention received the booklet at the enrollment visit, eligible first-degree relatives were limited to those who were alive the day after proband enrollment and not enrolled on the same day as the proband.

RESULTS

Between June 2016 and March 2020, 1241 probands were randomized (1:1) to receive Family Heart Talk (n=621) or not (n=620) within strata defined by site and self-identified race/ethnicity (non-Hispanic Black, non-Hispanic White, or Hispanic). Final analyses included 550 families (n=2230 eligible first-degree relatives) in the Family Heart Talk arm and 561 (n=2416) in the control arm. A higher percentage of eligible first-degree relatives completed screening in the Family Heart Talk arm (19.5% versus 16.0%), and the odds of screening completion among these first-degree relatives were higher in the Family Heart Talk arm after adjustment for proband randomization stratum, sex, and age quartile (odds ratio, 1.30 [1-sided 95% CI, 1.08-∞]). A prespecified subgroup analysis did not find evidence of heterogeneity in the adjusted intervention odds ratio across race/ethnicity strata (P=0.90).

CONCLUSIONS

Family Heart Talk, a booklet that can be provided to patients with DCM by clinicians with minimal additional time investment, was effective in increasing cardiovascular clinical screening among first-degree relatives of these patients.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT03037632.

Prevalence and Cumulative Risk of Familial Idiopathic Dilated Cardiomyopathy

Importance

Idiopathic dilated cardiomyopathy (DCM) aggregates in families, and early detection in at-risk family members can provide opportunity to initiate treatment prior to late-phase disease. Most studies have included only White patients, yet Black patients with DCM have higher risk of heart failure-related hospitalization and death.

Objective

To estimate the prevalence of familial DCM among DCM probands and the age-specific cumulative risk of DCM in first-degree relatives across race and ethnicity groups.

Design, Setting, and Participants

A family-based, cross-sectional study conducted by a multisite consortium of 25 US heart failure programs. Participants included patients with DCM (probands), defined as left ventricular systolic dysfunction and left ventricular enlargement after excluding usual clinical causes, and their first-degree relatives. Enrollment commenced June 7, 2016; proband and family member enrollment concluded March 15, 2020, and April 1, 2021, respectively.

Exposures

The presence of DCM in a proband.

Main Outcomes and Measures

Familial DCM defined by DCM in at least 1 first-degree relative; expanded familial DCM defined by the presence of DCM or either left ventricular enlargement or left ventricular systolic dysfunction without known cause in at least 1 first-degree relative.

Results

The study enrolled 1220 probands (median age, 52.8 years [IQR, 42.4-61.8]; 43.8% female; 43.1% Black and 8.3% Hispanic) and screened 1693 first-degree relatives for DCM. A median of 28% (IQR, 0%-60%) of living first-degree relatives were screened per family. The crude prevalence of familial DCM among probands was 11.6% overall. The model-based estimate of the prevalence of familial DCM among probands at a typical US advanced heart failure program if all living first-degree relatives were screened was 29.7% (95% CI, 23.5% to 36.0%) overall. The estimated prevalence of familial DCM was higher in Black probands than in White probands (difference, 11.3% [95% CI, 1.9% to 20.8%]) but did not differ significantly between Hispanic probands and non-Hispanic probands (difference, -1.4% [95% CI, -15.9% to 13.1%]). The estimated prevalence of expanded familial DCM was 56.9% (95% CI, 50.8% to 63.0%) overall. Based on age-specific disease status at enrollment, estimated cumulative risks in first-degree relatives at a typical US advanced heart failure program reached 19% (95% CI, 13% to 24%) by age 80 years for DCM and 33% (95% CI, 27% to 40%) for expanded DCM inclusive of partial phenotypes. The DCM hazard was higher in first-degree relatives of non-Hispanic Black probands than non-Hispanic White probands (hazard ratio, 1.89 [95% CI, 1.26 to 2.83]).

Conclusions and Relevance

In a US cross-sectional study, there was substantial estimated prevalence of familial DCM among probands and modeled cumulative risk of DCM among their first-degree relatives.

Trial Registration

ClinicalTrials.gov Identifier: NCT03037632.

An early relook identifies high-risk trajectories in ambulatory advanced heart failure

INTRODUCTION

Patients with ambulatory advanced heart failure (HF) are increasingly considered for durable mechanical circulatory support (MCS) and heart transplantation and their effective triage requires careful assessment of the clinical trajectory.

METHODS

REVIVAL, a prospective, observational study, enrolled 400 ambulatory advanced HF patients from 21 MCS/transplant centers in 2015-2016. Study design included a clinical re-assessment of Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profile within 120 days after enrollment. The prognostic impact of a worsening INTERMACS Profile assigned by the treating physician was assessed at 1 year after the Early Relook.

RESULTS

Early Relook was done in 325 of 400 patients (81%), of whom 24% had a worsened INTERMACS Profile, associated with longer HF history and worse baseline INTERMACS profile, but no difference in baseline LVEF (median 0.20), 6-minute walk, quality of life, or other baseline parameters. Early worsening predicted higher rate of the combined primary endpoint of death, urgent MCS, or urgent transplant by 1 year after Early Relook, (28% vs 15%), with hazard ratio 2.2 (95% CI 1.2- 3.8; p = .006) even after adjusting for baseline INTERMACS Profile and Seattle HF Model score. Deterioration to urgent MCS occurred in 14% vs 5% (p = .006) during the year after Early Relook.

CONCLUSIONS

Early Relook identifies worsening of INTERMACS Profile in a significant population of ambulatory advanced HF, who had worse outcomes over the subsequent year. Early reassessment of ambulatory advanced HF patients should be performed to better define the trajectory of illness and inform triage to advanced therapies.

Competing Risks to Transplant in Bridging with Continuous Flow Left Ventricular Assist Devices

BACKGROUND

Continuous flow left ventricular assist device(CF-LVAD) support is a mainstay in the hemodynamic management of patients with end-stage heart failure refractory to optimal medical therapy. In this report, we evaluated waitlist complications and competing outcomes for CF-LVAD patients compared to primary transplant candidates listed for orthotopic heart transplantation(OHT) at a single center.

METHODS

All patients listed for OHT between 2006-2020 at our institution were retrospectively reviewed(n=300 CF-LVAD; n=244 primary transplant). Kaplan-Meier methodology with log-rank testing was used to evaluate survival outcomes. Terminal outcomes of death, delisting, and transplant were assessed as competing risks and compared between groups using Gray's test. Multivariable Fine-Gray regression was used to identify predictors of transplantation.

RESULTS

One-year rates of transplant, delisting, and death were 48%, 8%, and 2%, respectively for CF-LVAD patients and 45%, 15%, and 9% for primary transplant(all P<0.001). Waitlist mortality at 5 years was 4% among CF-LVAD patients and 13% for primary transplants. All-cause mortality after listing was lower for CF-LVAD patients(P=0.017). There was no difference in post-transplant survival between groups(P=0.250). On multivariable Fine-Gray regression, stroke(P=0.017), respiratory failure(P=0.032), right ventricular failure(P=0.019), and driveline infection(P=0.050) were associated with decreased probability of transplantation. Post-transplant survival was not significantly worse for CF-LVAD patients who experienced device-related complications(P=0.901).

CONCLUSIONS

While device related-complications were significantly associated with decreased rates of transplant, CF-LVAD patients had excellent waitlist outcomes overall. In light of the 2018 allocation score change, the risk of complications should be taken into account when deciding whether to offer CF-LVAD as a bridge to transplant.

Acute kidney injury post-heart transplant: An analysis of peri-operative risk factors

Acute kidney injury is a common complication following heart transplantation, and the factors contributing to acute kidney injury are not well understood. We conducted a retrospective cohort study evaluating patients who underwent heart transplantation between 2009 and 2016 at a single institution. The primary endpoint was incidence of acute kidney injury as defined by Kidney Disease Improving Global Outcomes criteria. Secondary endpoints included 30-day hospital readmission, 30-day mortality, and 1-year mortality. A total of 228 heart transplant patients were included in the study for analysis. In total, 145 (64%) developed acute kidney injury, where 43 (30%) were classified as stage I, 28 (19%) as stage II, and 74 (51%) as stage III. Risk factors found to be associated with the presence of acute kidney injury included increased use of vasopressors and inotropes post-transplant. Protective factors included cardiopulmonary bypass time <170 min. Acute kidney injury was found to be associated with increased 30-day and 1-year mortality.

30 Years of Heart Transplant: Outcomes after Mechanical Circulatory Support from a Single Center

BACKGROUND

Survival after bridge to transplant with mechanical circulatory support (MCS) has yielded varying outcomes based on device type and baseline characteristics Continuous flow left ventricular assist devices (CF-LVADs) have significantly improved waitlist mortality, but recent changes to the transplant listing criteria have dramatically altered the use of MCS for bridge to transplant.

METHODS

Orthotopic heart transplants from 1988-2019 at our institution were retrospectively reviewed and stratified by pre-transplant MCS status into CF-LVAD (n=224), Pulsatile LVAD (n=49), temporary MCS (n=71), and primary transplant (n=463) groups. Patients transplanted after the approval of CF-LVAD for bridge to transplant and before the 2018 allocation policy changes underwent subgroup analysis to evaluate predictors of survival and complications in a contemporary cohort.

RESULTS

Rates of primary transplant declined from 88% to 14% over the course of the study. No significant difference in survival was detected in the cohort stratified by MCS status (P=0.18). In the modern era, survival for CF-LVAD and temporary MCS patients was non-inferior to primary transplant (P=0.22). Notable predictors of long-term mortality included lower body mass index, peripheral vascular disease, prior coronary artery bypass graft, ABO non-identical transplant, and increased donor age (all P<0.02). There were no differences in major postoperative complications.

CONCLUSIONS

CF-LVAD has grown to account for the majority of transplants at our center in the last decade with no adverse effect on survival or postoperative complications. Temporary MCS has increased following the 2018 listing criteria change with acceptable early outcomes.

Machine Learning Outcome Prediction in Dilated Cardiomyopathy Using Regional Left Ventricular Multiparametric Strain

The clinical presentation of idiopathic dilated cardiomyopathy (IDCM) heart failure (HF) patients who will respond to medical therapy (responders) and those who will not (non-responders) is often similar. A machine learning (ML)-based clinical tool to identify responders would prevent unnecessary surgery, while targeting non-responders for early intervention. We used regional left ventricular (LV) contractile injury patterns in ML models to identify IDCM HF non-responders. MRI-based multiparametric strain analysis was performed in 178 test subjects (140 normal subjects and 38 IDCM patients), calculating longitudinal, circumferential, and radial strain over 18 LV sub-regions for inclusion in ML analyses. Patients were identified as responders based upon symptomatic and contractile improvement on medical therapy. We tested the predictive accuracy of support vector machines (SVM), logistic regression (LR), random forest (RF), and deep neural networks (DNN). The DNN model outperformed other models, predicting response to medical therapy with an area under the receiver operating characteristic curve (AUC) of 0.94. The top features were longitudinal strain in (1) basal: anterior, posterolateral and (2) mid: posterior, anterolateral, and anteroseptal sub-regions. Regional contractile injury patterns predict response to medical therapy in IDCM HF patients, and have potential application in ML-based HF patient care.

Cardiac allograft rejection in the current era of continuous flow left ventricular assist devices

OBJECTIVE

Left ventricular assist device (LVAD) implantation has been shown to increase allosensitization before orthotopic heart transplantation, but the influence of LVAD support on posttransplant rejection is controversial. This study examines the postoperative incidence of acute cellular rejection (ACR) in patients bridged with continuous flow LVAD (CF-LVAD) relative to primary transplant (Primary Tx).

METHODS

All patients who underwent orthotopic heart transplantation at our institution between July 2006 and March 2019 were retrospectively reviewed (n = 395). Patients were classified into Primary Tx (n = 145) and CF-LVAD (n = 207) groups. Propensity score matching on 13 covariates implemented a 0.1 caliper logistic model with nearest neighbor 1:1 matching. Development of moderate to severe (ie, 2R/3R) rejection was evaluated using a competing risks model. Potential predictors of 2R/3R ACR were evaluated using Fine-Gray regression on the marginal subdistribution hazard.

RESULTS

Propensity score matching yielded 122 patients in each group (n = 244). At 12 and 24 months, the cumulative incidence of 2R/3R ACR was 17% and 23% for the CF-LVAD group and 26% and 31%, respectively, for the Primary Tx group (P = .170). CF-LVAD was not predictive of 2R/3R rejection on multivariable Fine-Gray regression (subdistribution hazard ratio, 0.73; 95% confidence interval, 0.40-1.33; P = .301). There was no difference in the 5-year incidence of antibody mediated rejection (10% [n = 12] vs 9% [n = 11]; P = .827).

CONCLUSIONS

After adjusting for covariates, CF-LVAD was not associated with an increased risk of moderate to severe ACR during the 24 months after cardiac transplantation. Further investigation is warranted with larger cohorts, but CF-LVAD may have minimal influence on posttransplant ACR.

Comorbid Conditions and Health-Related Quality of Life in Ambulatory Heart Failure Patients: REVIVAL (Registry Evaluation of Vital Information for VADs in Ambulatory Life REVIVAL)

BACKGROUND

Patients with heart failure (HF) often have multiple chronic conditions that may impact health-related quality of life (HRQOL) despite HF therapy. We sought to determine the association between noncardiac comorbidities and HRQOL in ambulatory patients with advanced HF.

METHODS

Baseline data from 373 subjects in REVIVAL (Registry Evaluation of Vital Information for Ventricular Assist Devices in Ambulatory Life) were analyzed using multivariable general linear models to evaluate the relationship between comorbidities and HRQOL (EuroQol Visual Analogue Scale, EQ-5D-3L Index Score, and Kansas City Cardiomyopathy Questionnaire). The primary independent variables were a comorbidity index (sum of 14 noncardiac conditions), a residual comorbidity index (without depression), and depression alone. The median (25th to 75th percentile) number of comorbidities was 3 (2-4).

RESULTS

Increasing comorbidity burden was associated with a reduction in generic (EQ-5D Index, P=0.005) and HF-specific (Kansas City Cardiomyopathy Questionnaire, P=0.001) HRQOL. The residual comorbidity index was not associated with HRQOL when depression included in the model independently, while depression was associated with HRQOL across all measures. Participants with depression (versus without) scored on average 13 points (95% CI, 8-17) lower on the EuroQol Visual Analogue Scale, 0.15 points (95% CI, 0.12-0.18) lower on the EQ-5D Index, and 24.9 points (95% CI, 21.2-28.5) lower on the Kansas City Cardiomyopathy Questionnaire overall summary score.

CONCLUSIONS

While noncardiac comorbidities were prevalent in ambulatory advanced HF patients, only depression was associated with decreased generic and HF-specific HRQOL. Other than depression, the presence of noncardiac comorbidities should not impact expected gains in HRQOL following ventricular assist device implantation, provided the conditions are not a contraindication to implant. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01369407.

Cerebrovascular Events After Continuous-Flow Left Ventricular Assist Devices

BACKGROUND

Cerebrovascular events (CVE) are among the most common and serious complications after implantation of continuous-flow left ventricular assist devices (CF-LVAD). We studied the incidence, subtypes, anatomical distribution, and pre- and post-implantation risk factors of CVEs as well as the effect of CVEs on outcomes after CF-LVAD implantation at our institution.

METHODS

Retrospective analysis of clinical and neuroimaging data of 372 patients with CF-LVAD between May 2005 and December 2013 using standard statistical methods.

RESULTS

CVEs occurred in 71 patients (19%), consisting of 35 ischemic (49%), 26 hemorrhagic (37%), and 10 ischemic+hemorrhagic (14%) events. History of coronary artery disease and female gender was associated with higher odds of ischemic CVE (OR 2.84 and 2.5, respectively), and diabetes mellitus was associated with higher odds of hemorrhagic CVE (OR 3.12). While we found a higher rate of ischemic CVEs in patients not taking any antithrombotic medications, no difference was found between patients with ischemic and hemorrhagic CVEs. Occurrence of CVEs was associated with increased mortality (HR 1.62). Heart transplantation was associated with improved survival (HR 0.02). In patients without heart transplantation, occurrence of CVE was associated with decreased survival.

CONCLUSIONS

LVADs are associated with high rates of CVE, increased mortality, and lower rates of heart transplantation. Further investigations to identify the optimal primary and secondary stroke prevention measures in post-LVAD patients are warranted.

A Fully Magnetically Levitated Left Ventricular Assist Device - Final Report

BACKGROUND

In two interim analyses of this trial, patients with advanced heart failure who were treated with a fully magnetically levitated centrifugal-flow left ventricular assist device were less likely to have pump thrombosis or nondisabling stroke than were patients treated with a mechanical-bearing axial-flow left ventricular assist device.

METHODS

We randomly assigned patients with advanced heart failure to receive either the centrifugal-flow pump or the axial-flow pump irrespective of the intended goal of use (bridge to transplantation or destination therapy). The composite primary end point was survival at 2 years free of disabling stroke or reoperation to replace or remove a malfunctioning device. The principal secondary end point was pump replacement at 2 years.

RESULTS

This final analysis included 1028 enrolled patients: 516 in the centrifugal-flow pump group and 512 in the axial-flow pump group. In the analysis of the primary end point, 397 patients (76.9%) in the centrifugal-flow pump group, as compared with 332 (64.8%) in the axial-flow pump group, remained alive and free of disabling stroke or reoperation to replace or remove a malfunctioning device at 2 years (relative risk, 0.84; 95% confidence interval [CI], 0.78 to 0.91; P<0.001 for superiority). Pump replacement was less common in the centrifugal-flow pump group than in the axial-flow pump group (12 patients [2.3%] vs. 57 patients [11.3%]; relative risk, 0.21; 95% CI, 0.11 to 0.38; P<0.001). The numbers of events per patient-year for stroke of any severity, major bleeding, and gastrointestinal hemorrhage were lower in the centrifugal-flow pump group than in the axial-flow pump group.

CONCLUSIONS

Among patients with advanced heart failure, a fully magnetically levitated centrifugal-flow left ventricular assist device was associated with less frequent need for pump replacement than an axial-flow device and was superior with respect to survival free of disabling stroke or reoperation to replace or remove a malfunctioning device. (Funded by Abbott; MOMENTUM 3 ClinicalTrials.gov number, NCT02224755.).

Heartland virus infection in a heart transplant recipient from the Heartland

Tick-borne infections represent a significant health risk each year in the United States. Immunocompromised patients are typically at risk of more severe disease manifestations than their immunocompetent counterparts. Here we report a case of a newly emerging phlebovirus, Heartland virus, in a heart transplant recipient.

Two-Year Outcomes with a Magnetically Levitated Cardiac Pump in Heart Failure

BACKGROUND

In an early analysis of this trial, use of a magnetically levitated centrifugal continuous-flow circulatory pump was found to improve clinical outcomes, as compared with a mechanical-bearing axial continuous-flow pump, at 6 months in patients with advanced heart failure.

METHODS

In a randomized noninferiority and superiority trial, we compared the centrifugal-flow pump with the axial-flow pump in patients with advanced heart failure, irrespective of the intended goal of support (bridge to transplantation or destination therapy). The composite primary end point was survival at 2 years free of disabling stroke (with disabling stroke indicated by a modified Rankin score of >3; scores range from 0 to 6, with higher scores indicating more severe disability) or survival free of reoperation to replace or remove a malfunctioning device. The noninferiority margin for the risk difference (centrifugal-flow pump group minus axial-flow pump group) was -10 percentage points.

RESULTS

Of 366 patients, 190 were assigned to the centrifugal-flow pump group and 176 to the axial-flow pump group. In the intention-to-treat population, the primary end point occurred in 151 patients (79.5%) in the centrifugal-flow pump group, as compared with 106 (60.2%) in the axial-flow pump group (absolute difference, 19.2 percentage points; 95% lower confidence boundary, 9.8 percentage points [P<0.001 for noninferiority]; hazard ratio, 0.46; 95% confidence interval [CI], 0.31 to 0.69 [P<0.001 for superiority]). Reoperation for pump malfunction was less frequent in the centrifugal-flow pump group than in the axial-flow pump group (3 patients [1.6%] vs. 30 patients [17.0%]; hazard ratio, 0.08; 95% CI, 0.03 to 0.27; P<0.001). The rates of death and disabling stroke were similar in the two groups, but the overall rate of stroke was lower in the centrifugal-flow pump group than in the axial-flow pump group (10.1% vs. 19.2%; hazard ratio, 0.47; 95% CI, 0.27 to 0.84, P=0.02).

CONCLUSIONS

In patients with advanced heart failure, a fully magnetically levitated centrifugal-flow pump was superior to a mechanical-bearing axial-flow pump with regard to survival free of disabling stroke or reoperation to replace or remove a malfunctioning device. (Funded by Abbott; MOMENTUM 3 ClinicalTrials.gov number, NCT02224755 .).

Diagnosis of LVAD Thrombus using a High-Avidity Fibrin-Specific 99mTc Probe

Treatment of advanced heart failure with implantable LVADs is increasing, driven by profound unmet patient need despite potential serious complications: bleeding, infection, and thrombus. The experimental objective was to develop a sensitive imaging approach to assess early thrombus accumulation in LVADs under operational high flow and high shear rates.

Methods: A monomeric bifunctional ligand with a fibrin-specific peptide, a short spacer, and ^99mTc chelating amino acid sequence (F1A) was developed and compared to its tetrameric PEG analogue (F4A).

Results: ^99mTc attenuation by LVAD titanium (1 mm) was 23%. ^99mTc-F1A affinity to fibrin was K_d ~10 µM, whereas, the bound ^99mTc-F4A probe was not displaced by F1A (120,000:1). Human plasma interfered with ^99mTc-F1A binding to fibrin clot (p<0.05) in vitro, whereas, ^99mTc-F4A targeting was unaffected. The pharmacokinetic half-life of ^99mTc-F4A was 28% faster (124±41 min) than ^99mTc-F1A (176±26 min) with both being bioeliminated through the urinary system with negligible liver or spleen biodistribution. In mice with carotid thrombus, ^99mTc-F4A binding to the injured carotid was much greater (16.3±3.3 %ID/g, p=0.01) than that measured with an irrelevant negative control, ^99mTc-I4A (3.4±1.6 %ID/g). In an LVAD mock flow-loop (1:1, PBS:human plasma:heparin) operating at maximal flow rate, ^99mTc-F4A bound well to phantom clots in 2 min (p<0.05), whereas ^99mTc-F1A had negligible targeting. Excised LVADs from patients undergoing pump exchange or heart transplant were rewired, studied in the mock flow loop, and found to have spatially variable fibrin accumulations in the inlet and outlet cannulas and bearings.

Conclusions:^99mTc-F4A is a high-avidity prototype probe for characterizing thrombus in LVADs that is anticipated to help optimize anticoagulation, reduce thromboembolic events, and minimize pump exchange.

Relationship Between Anticoagulation Intensity and Thrombotic or Bleeding Outcomes Among Outpatients With Continuous-Flow Left Ventricular Assist Devices

BACKGROUND

We evaluated thrombotic and bleeding outcomes in patients with continuous-flow left ventricular assist devices (CF-LVADs), stratified by anticoagulation intensity. Previous studies of outpatients with CF-LVADs have suggested that target international normalized ratio (INR) values <2.5 (range, 2-3) may be used. However, recent studies reported an increase in pump thrombosis among CF-LVADs, especially within the first 6 months of implant.

METHODS AND RESULTS

We retrospectively reviewed 249 outpatients at our center who received a CF-LVAD between January 2005 and August 2013. Using Poisson models, we analyzed their 10 927 INRs to determine INR-specific rates of thrombotic (ischemic stroke and suspected pump thrombosis) and hemorrhagic (gastrointestinal bleeding and hemorrhagic stroke) events occurring outside of the hospital. In multivariate analyses, we adjusted for age, sex, atrial fibrillation, coronary disease, and LVAD type as time-dependent Cox proportional hazard models. During a mean follow-up of 17.6±13.6 months, thrombotic events occurred in 46 outpatients. The highest event rate (0.40 thrombotic events per patient-year) was in the INR range of <1.5, but INR values of 1.5 to 1.99 also had high rates (0.16 thrombotic events per patient-year). INR was inversely associated with thrombotic events (hazard ratio, 0.40; 95% confidence interval, 0.22-0.72; P=0.002). The optimal INR based on weighted mortality of thrombotic and bleeding events was 2.6.

CONCLUSIONS

INR is inversely related to thrombotic events occurring outside of the hospital among patients supported with CF-LVADs. INR values <2.0 increase the rate of thrombotic events occurring outside of the hospital among patients supported with CF-LVADs.

Hemocompatibility-Related Outcomes in the MOMENTUM 3 Trial at 6 Months

Background:

The HeartMate 3 (HM3) Left Ventricular Assist System (LVAS) (Abbott) is a centrifugal, fully magnetically levitated, continuous-flow blood pump engineered to enhance hemocompatibility and reduce shear stress on blood components. The MOMENTUM 3 trial (Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy With HeartMate 3) compares the HM3 LVAS with the HeartMate II (HMII) LVAS (Abbott) in advanced heart failure refractory to medical management, irrespective of therapeutic intention (bridge to transplant versus destination therapy). This investigation reported its primary outcome in the short-term cohort (n=294; 6-month follow-up), demonstrating superiority of the HM3 for the trial primary end point (survival free of a disabling stroke or reoperation to replace the pump for malfunction), driven by a reduced need for reoperations. The aim of this analysis was to evaluate the aggregate of hemocompatibility-related clinical adverse events (HRAEs) between the 2 LVAS.

Methods:

We conducted a secondary end point evaluation of HRAE (survival free of any nonsurgical bleeding, thromboembolic event, pump thrombosis, or neurological event) in the short-term cohort (as-treated cohort n=289) at 6 months. The net burden of HRAE was also assessed by using a previously described hemocompatibility score, which uses 4 escalating tiers of hierarchal severity to derive a total score for events encountered during the entire follow-up experience for each patient.

Results:

In 289 patients in the as-treated group (151 the HM3 and 138 the HMII), survival free of any HRAE was achieved in 69% of the HM3 group and in 55% of the HMII group (hazard ratio, 0.62; confidence interval, 0.42–0.91; P =0.012). Using the hemocompatibility score, the HM3 group demonstrated less pump thrombosis requiring reoperation (0 versus 36 points, P <0.001) or medically managed pump thrombosis (0 versus 5 points, P =0.02), and fewer nondisabling strokes (6 versus 24 points, P =0.026) than the control HMII LVAS. The net hemocompatibility score in the HM3 in comparison with the HMII patients was 101 (0.67±1.50 points/patient) versus 137 (0.99±1.79 points/patient) (odds ratio, 0.64; confidence interval, 0.39–1.03; P =0.065).

Conclusions:

In this secondary analysis of the MOMENTUM 3 trial, the HM3 LVAS demonstrated greater freedom from HRAEs in comparison with the HMII LVAS at 6 months.

Clinical Trial Registration:

URL: http://clinicaltrials.gov . Unique identifier: NCT02224755.

Global Outcome in Patients With Left Ventricular Assist Devices

Left ventricular assist devices (LVADs) improve survival and quality of life (QOL) for most, but not all, patients with advanced heart failure. We described a broader definition of poor outcomes after LVAD, using a novel composite of death, QOL, and other major adverse events. We evaluated the frequency of poor global outcome at 1 year after LVAD among 164 patients (86% Interagency Registry for Mechanically Assisted Circulatory Support profile 1 to 2; shock or declining despite inotropes) at a high-volume center. Poor global outcome (comprising death, poor QOL [Kansas City Cardiomyopathy Questionnaire <45], recurrent heart failure [≥2 heart failure readmissions], or severe stroke) occurred in 58 patients (35%): 37 died, 17 had poor QOL, 3 had recurrent heart failure, and 1 had a severe stroke. Patients with poor global outcomes were more likely designated for destination therapy (46% vs 24%, p = 0.01), spent more days hospitalized per month alive (median [interquartile range] 18.6 [5.0 to 31.0] vs 3.7 [1.8 to 8.3], p <0.001), and had higher intracranial (12% vs 2%, p = 0.031) and gastrointestinal (44% vs 28%, p = 0.056) hemorrhage rates over the year after implant. Although LVADs often improve survival and QOL, ∼1/3 of high-acuity patients experienced a poor global outcome over the year after LVAD. In conclusion, composite outcomes may better capture events that matter to patients with LVADs and thus support informed decisions about pursuing LVAD therapy.

A Fully Magnetically Levitated Circulatory Pump for Advanced Heart Failure

BACKGROUND

Continuous-flow left ventricular assist systems increase the rate of survival among patients with advanced heart failure but are associated with the development of pump thrombosis. We investigated the effects of a new magnetically levitated centrifugal continuous-flow pump that was engineered to avert thrombosis.

METHODS

We randomly assigned patients with advanced heart failure to receive either the new centrifugal continuous-flow pump or a commercially available axial continuous-flow pump. Patients could be enrolled irrespective of the intended goal of pump support (bridge to transplantation or destination therapy). The primary end point was a composite of survival free of disabling stroke (with disabling stroke indicated by a modified Rankin score >3; scores range from 0 to 6, with higher scores indicating more severe disability) or survival free of reoperation to replace or remove the device at 6 months after implantation. The trial was powered for noninferiority testing of the primary end point (noninferiority margin, -10 percentage points).

RESULTS

Of 294 patients, 152 were assigned to the centrifugal-flow pump group and 142 to the axial-flow pump group. In the intention-to-treat population, the primary end point occurred in 131 patients (86.2%) in the centrifugal-flow pump group and in 109 (76.8%) in the axial-flow pump group (absolute difference, 9.4 percentage points; 95% lower confidence boundary, -2.1 [P<0.001 for noninferiority]; hazard ratio, 0.55; 95% confidence interval [CI], 0.32 to 0.95 [two-tailed P=0.04 for superiority]). There were no significant between-group differences in the rates of death or disabling stroke, but reoperation for pump malfunction was less frequent in the centrifugal-flow pump group than in the axial-flow pump group (1 [0.7%] vs. 11 [7.7%]; hazard ratio, 0.08; 95% CI, 0.01 to 0.60; P=0.002). Suspected or confirmed pump thrombosis occurred in no patients in the centrifugal-flow pump group and in 14 patients (10.1%) in the axial-flow pump group.

CONCLUSIONS

Among patients with advanced heart failure, implantation of a fully magnetically levitated centrifugal-flow pump was associated with better outcomes at 6 months than was implantation of an axial-flow pump, primarily because of the lower rate of reoperation for pump malfunction. (Funded by St. Jude Medical; MOMENTUM 3 ClinicalTrials.gov number, NCT02224755 .).

Use of adenosine diphosphate receptor inhibitor prior to left ventricular assist device implantation is not associated with increased bleeding

Current guidelines recommend adenosine diphosphate receptor inhibitors (ADPRi) be discontinued 5-7 days prior to cardiac surgery due to increased bleeding events, rates of re-exploration, and transfusions. However, the risks of left ventricular assist device (LVAD) implantation in patients taking an ADPRi have not previously been studied. We retrospectively identified 134 eligible patients with ischemic cardiomyopathy that underwent LVAD implantation between July 2009 and August 2013. The cohorts received an ADPRi ≤5 days of surgery (n = 25) versus >5 days prior or not at all (n = 109). Subgroup analyses adjusted for differences in frequency of redo sternotomy between cohorts, excluded patients that received an ADPRi >1 year prior to surgery, and excluded patients with a redo sternotomy. The ADPRi and control groups did not have significant differences in the primary outcomes, intraoperative PRBC units transfused (3.0 vs. 4.0, p = 0.12) or chest tube output within 24 h of surgery (1.66 L vs. 1.80 L, p = 0.61). After adjusting for differences in frequency of redo sternotomy (ADPRi vs. control, 12 vs. 52%, p ≤ 0.001), no significant difference in PRBC units transfused (3.1 vs. 3.5, p = 0.59) or chest tube output (2.04 L vs. 2.04 L, p = 0.98) was seen. No significant difference in 30-day mortality (8.0 vs. 11.0%, p = 0.63), 90-day mortality (16.4 vs. 23.3%, p = 0.42), or length of stay (29.0 vs. 28.0, p = 0.61) was seen. In this single-center experience, use of an ADPRi ≤5 days prior to LVAD implantation was not associated with increased bleeding, length of stay, or mortality.

The HVAD Left Ventricular Assist Device: Risk Factors for Neurological Events and Risk Mitigation Strategies

OBJECTIVES

The purpose of this study was to determine the risk factors for ischemic in hemorrhage cerebrovascular events in patients supported by the HeartWare ventricular assist device (HVAD).

BACKGROUND

Patients supported with left ventricular assist devices are at risk for both ischemic and hemorrhagic cerebrovascular events.

METHODS

Patients undergoing implantation with a HVAD as part of the bridge-to-transplant trial and subsequent continued access protocol were included. Neurological events (ischemic cerebrovascular accidents [ICVAs] and hemorrhagic cerebrovascular accidents [HCVAs]) were assessed, and the risk factors for these events were evaluated in a multivariable model.

RESULTS

A total of 382 patients were included: 140 bridge-to-transplant patients from the ADVANCE (Evaluation of the HeartWare Left Ventricular Assist Device for the Treatment of Advanced Heart Failure) clinical trial and 242 patients from the continued access protocol. Patients had a mean age of 53.2 years; 71.2% were male, and 68.1% were white. Thirty-eight percent had ischemic heart disease, and the mean duration of support was 422.7 days. The overall prevalence of ICVA was 6.8% (26 of 382); for HCVA, it was 8.4% (32 of 382). Pump design modifications and a protocol-driven change in the antiplatelet therapy reduced the prevalence of ICVA from 6.3% (17 of 272) to 2.7% (3 of 110; p = 0.21) but had a negligible effect on the prevalence of HVCA (8.8% [24 of 272] vs. 6.4% [7 of 110]; p = 0.69). Multivariable predictors of ICVA were aspirin ≤81 mg and atrial fibrillation; predictors of HCVA were mean arterial pressure >90 mm Hg, aspirin ≤81 mg, and an international normalized ratio >3.0. Eight of the 30 participating sites had established improved blood pressure management (IBPM) protocols. Although the prevalence of ICVA for those with and without IBPM protocols was similar (5.3% [6 of 114] vs. 5.2% [14 of 268]; p = 0.99), those with IBPM protocols had a significantly lower prevalence of HCVA (1.8% [2 of 114] vs. 10.8% [29 of 268]; p = 0.0078).

CONCLUSIONS

Anticoagulation, antiplatelet therapy, and blood pressure management affected the prevalence of cerebrovascular events after implantation of the HVAD. Attention to these clinical parameters can have a substantial impact on the occurrence of serious neurological events. (Evaluation of the HeartWare Left Ventricular Assist Device for the Treatment of Advanced Heart Failure [ADVANCE]; NCT00751972).

Relationship Between Anticoagulation Intensity and Thrombotic or Bleeding Outcomes Among Outpatients With Continuous-Flow Left Ventricular Assist Devices

BACKGROUND

We evaluated thrombotic and bleeding outcomes in patients with continuous-flow left ventricular assist devices (CF-LVADs), stratified by anticoagulation intensity. Previous studies of outpatients with CF-LVADs have suggested that target international normalized ratio (INR) values <2.5 (range, 2-3) may be used. However, recent studies reported an increase in pump thrombosis among CF-LVADs, especially within the first 6 months of implant.

METHODS AND RESULTS

We retrospectively reviewed 249 outpatients at our center who received a CF-LVAD between January 2005 and August 2013. Using Poisson models, we analyzed their 10 927 INRs to determine INR-specific rates of thrombotic (ischemic stroke and suspected pump thrombosis) and hemorrhagic (gastrointestinal bleeding and hemorrhagic stroke) events occurring outside of the hospital. In multivariate analyses, we adjusted for age, sex, atrial fibrillation, coronary disease, and LVAD type as time-dependent Cox proportional hazard models. During a mean follow-up of 17.6±13.6 months, thrombotic events occurred in 46 outpatients. The highest event rate (0.40 thrombotic events per patient-year) was in the INR range of <1.5, but INR values of 1.5 to 1.99 also had high rates (0.16 thrombotic events per patient-year). INR was inversely associated with thrombotic events (hazard ratio, 0.40; 95% confidence interval, 0.22-0.72; P=0.002). The optimal INR based on weighted mortality of thrombotic and bleeding events was 2.6.

CONCLUSIONS

INR is inversely related to thrombotic events occurring outside of the hospital among patients supported with CF-LVADs. INR values <2.0 increase the rate of thrombotic events occurring outside of the hospital among patients supported with CF-LVADs.

Mitochondrial structure and function are not different between nonfailing donor and end-stage failing human hearts

During human heart failure, the balance of cardiac energy use switches from predominantly fatty acids (FAs) to glucose. We hypothesized that this substrate shift was the result of mitochondrial degeneration; therefore, we examined mitochondrial oxidation and ultrastructure in the failing human heart by using respirometry, transmission electron microscopy, and gene expression studies of demographically matched donor and failing human heart left ventricular (LV) tissues. Surprisingly, respiratory capacities for failing LV isolated mitochondria (n = 9) were not significantly diminished compared with donor LV isolated mitochondria (n = 7) for glycolysis (pyruvate + malate)- or FA (palmitoylcarnitine)-derived substrates, and mitochondrial densities, assessed via citrate synthase activity, were consistent between groups. Transmission electron microscopy images also showed no ultrastructural remodeling for failing vs. donor mitochondria; however, the fraction of lipid droplets (LDs) in direct contact with a mitochondrion was reduced, and the average distance between an LD and its nearest neighboring mitochondrion was increased. Analysis of FA processing gene expression between donor and failing LVs revealed 0.64-fold reduced transcript levels for the mitochondrial-LD tether, perilipin 5, in the failing myocardium (P = 0.003). Thus, reduced FA use in heart failure may result from improper delivery, potentially via decreased perilipin 5 expression and mitochondrial-LD tethering, and not from intrinsic mitochondrial dysfunction.-Holzem, K. M., Vinnakota, K. C., Ravikumar, V. K., Madden, E. J., Ewald, G. A., Dikranian, K., Beard, D. A., Efimov, I. R. Mitochondrial structure and function are not different between nonfailing donor and end-stage failing human hearts.

Treatment of secondary pulmonary hypertension with bosentan after left ventricular assist device implantation

INTRODUCTION

Secondary pulmonary hypertension (PH) and right ventricular dysfunction are common and associated with poor prognosis in HF patients with left ventricular assist devices (LVADs). The role of pulmonary vasodilator therapy for these patients is currently unclear.

AIMS

We sought to evaluate the safety and clinical course of patients treated with bosentan, an endothelin receptor antagonist, after the implementation of a LVAD.

RESULTS

Between 10/2008 and 5/2011, 50 consecutive patients with mean PAP >25 mmHg were treated with bosentan after LVAD implantation for a mean duration of 15.7 (±12.4) months. Ten patients discontinued the drug for possible side effects, including three for LFT abnormalities. Comparison of baseline to 6-month follow-up data revealed laboratory evidence for decongestion with a decrease in bilirubin (2.3-0.6, P < 0.0001) and an improvement in pulmonary hemodynamics with echocardiographically calculated mean PVR decreasing 1.4 woods units (3.93 ± 1.53 to 2.58 ± 1.05, P < 0.0001).

CONCLUSION

In this single-centered retrospective case series, we provide evidence that the tolerability of bosentan in LVAD-supported patients with secondary PH is comparable to prior experience in patients with heart failure.

Reduced response to IKr blockade and altered hERG1a/1b stoichiometry in human heart failure

Heart failure (HF) claims 250,000 lives per year in the US, and nearly half of these deaths are sudden and presumably due to ventricular tachyarrhythmias. QT interval and action potential (AP) prolongation are hallmark proarrhythmic changes in the failing myocardium, which potentially result from alterations in repolarizing potassium currents. Thus, we aimed to examine whether decreased expression of the rapid delayed rectifier potassium current, IKr, contributes to repolarization abnormalities in human HF. To map functional IKr expression across the left ventricle (LV), we optically imaged coronary-perfused LV free wall from donor and end-stage failing human hearts. The LV wedge preparation was used to examine transmural AP durations at 80% repolarization (APD80), and treatment with the IKr-blocking drug, E-4031, was utilized to interrogate functional expression. We assessed the percent change in APD80 post-IKr blockade relative to baseline APD80 (∆APD80) and found that ∆APD80s are reduced in failing versus donor hearts in each transmural region, with 0.35-, 0.43-, and 0.41-fold reductions in endo-, mid-, and epicardium, respectively (p=0.008, 0.037, and 0.022). We then assessed hERG1 isoform gene and protein expression levels using qPCR and Western blot. While we did not observe differences in hERG1a or hERG1b gene expression between donor and failing hearts, we found a shift in the hERG1a:hERG1b isoform stoichiometry at the protein level. Computer simulations were then conducted to assess IKr block under E-4031 influence in failing and nonfailing conditions. Our results confirmed the experimental observations and E-4031-induced relative APD80 prolongation was greater in normal conditions than in failing conditions, provided that the cellular model of HF included a significant downregulation of IKr. In human HF, the response to IKr blockade is reduced, suggesting decreased functional IKr expression. This attenuated functional response is associated with altered hERG1a:hERG1b protein stoichiometry in the failing human LV, and failing cardiomyoctye simulations support the experimental findings. Thus, of IKr protein and functional expression may be important determinants of repolarization remodeling in the failing human LV.

The Heartmate Risk Score predicts morbidity and mortality in unselected left ventricular assist device recipients and risk stratifies INTERMACS class 1 patients

OBJECTIVES

This study evaluated the Heartmate Risk Score (HMRS) and its potential benefits in clinical practice.

BACKGROUND

The HMRS has been shown to correlate with mortality in the cohort of patients enrolled in the Heartmate II trials, but its validity in unselected, "real world" populations remains unclear.

METHODS

This study identified a cohort of 269 consecutive patients who received a Heartmate II left ventricular assist device at our institution, the Barnes-Jewish Hospital in St. Louis, Missouri, between June 2005 and June 2013. Ninety-day and 2-year mortality rates, as well as frequency of several morbid events, were compared by retrospectively assigned HMRS category groups. The analysis was repeated within the subgroup of INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support) class 1 patients.

RESULTS

Receiver operating curve analysis showed that the HMRS correlated with 90-day mortality with an area under the curve of 0.70. Stratification in low, mid, and high HMRS groups identified patients with increasing hazard of 90-day mortality, increasing long-term mortality, increasing rate of gastrointestinal bleeding events, and increasing median number of days spent in the hospital in the first year post implant. Within INTERMACS class 1 patients, those in the highest HMRS group were found to have a relative risk of 90-day mortality 5.7 times higher than those in the lowest HMRS group (39.1% vs. 6.9%, p = 0.029).

CONCLUSIONS

HMRS is a valid clinical tool to stratify risk of morbidity and mortality after implant of Heartmate II devices in unselected patients and can be used to predict short-term mortality risk in INTERMACS class 1 patients.

Arrhythmogenic remodeling of β2 versus β1 adrenergic signaling in the human failing heart

BACKGROUND

Arrhythmia is the major cause of death in patients with heart failure, for which β-adrenergic receptor blockers are a mainstay therapy. But the role of β-adrenergic signaling in electrophysiology and arrhythmias has never been studied in human ventricles.

METHODS AND RESULTS

We used optical imaging of action potentials and [Ca(2+)]i transients to compare the β1- and β2-adrenergic responses in left ventricular wedge preparations of human donor and failing hearts. β1-Stimulation significantly increased conduction velocity, shortened action potential duration, and [Ca(2+)]i transients duration (CaD) in donor but not in failing hearts, because of desensitization of β1-adrenergic receptor in heart failure. In contrast, β2-stimulation increased conduction velocity in both donor and failing hearts but shortened action potential duration only in failing hearts. β2-Stimulation also affected transmural heterogeneity in action potential duration but not in [Ca(2+)]i transients duration. Both β1- and β2-stimulation augmented the vulnerability and frequency of ectopic activity and enhanced substrates for ventricular tachycardia in failing, but not in donor, hearts. Both β1- and β2-stimulation enhanced Purkinje fiber automaticity, whereas only β2-stimulation promoted Ca-mediated premature ventricular contractions in heart failure.

CONCLUSIONS

During end-stage heart failure, β2-stimulation creates arrhythmogenic substrates via conduction velocity regulation and transmurally heterogeneous repolarization. β2-Stimulation is, therefore, more arrhythmogenic than β1-stimulation. In particular, β2-stimulation increases the transmural difference between [Ca(2+)]i transients duration and action potential duration, which facilitates the formation of delayed afterdepolarizations.

Gene expression profiling to study racial differences after heart transplantation

Background

The basis for increased mortality after heart transplantation in African Americans and other non-Caucasian racial groups is poorly defined. We hypothesized that increased risk of adverse events is driven by biological factors. To test this hypothesis in the IMAGE study, we determined whether the event rate of the primary outcome of acute rejection, graft dysfunction, death, or re-transplantation varied by race as a function of calcineurin inhibitor levels and gene expression profile (GEP) scores.

Methods

We determined the event rate of the primary outcome, comparing racial groups, stratified by time post-transplant. Logistic regression was used to compute the relative risk across racial groups and linear modeling was used to measure the dependence of CNI levels and GEP score on race.

Results

In 580 patients followed for a median of 19 months, the incidence of the primary endpoint in African Americans, other non-Caucasians, and Caucasians was 18.3%, 22.2%, and 8.5%, respectively (p<0.001). There were small but significant correlations of race and tacrolimus trough levels to GEP score. Tacrolimus levels were similar between races. Of patients receiving tacrolimus, other non-Caucasians had higher GEP scores than the other racial groups. African American recipients demonstrated a unique decrease in expression of the FLT3 gene in response to higher tacrolimus levels.

Conclusions

African Americans and other non-Caucasian heart transplant recipients were 2.5–3 times more likely than Caucasians to experience outcome events in IMAGE. The increased risk of adverse outcomes may be partly due to the biology of the alloimmune response, which is less effectively inhibited at similar tacrolimus levels in minority racial groups.

Abstract W P163: Ischemic and Hemorrhagic Cerebrovascular Events after Left Ventricular Assist Devices

Introduction: Left ventricular assist devices (LVADs) are increasingly implanted for advanced heart failure either as a bridge to transplantation (BTT) or destination therapy (DT). The reported incidence of cerebrovascular events (CVE) following LVAD is 8-25%. The effects of medical comorbidities and perioperative events on the development of CVE are unclear.

Methods: CVEs were retrospectively identified from the Barnes-Jewish Hospital LVAD database consisting of 373 patients with mean LVAD support of 13.5 months (range 0 days-8.2 years); Heartmate II 87%, Heartware 13%. Demographic, clinical, and outcome data were collected and analyzed in patients with and without CVE using standard statistical methods.

Results: CVE occurred in 71 patients (19%) at a rate of 0.17 per patient-year 24.5±30.7 months after implantation. Coronary artery disease (P=0.007), diabetes mellitus (P=0.02) and LVAD indication of DT (P=0.04) were more common in patients with CVEs. Duration of cardiopulmonary bypass, hospital length of stay and incidence of bacteremia were not different between those with early CVE (within 30 days of implantation, 35%) and without CVE. CVEs were ischemic (ICVE) in 35 (49%), hemorrhagic (HCVE, including intracerebral, subarachnoid, and subdural) in 26 (37%), and both in 10 (14%). Patients with ICVE and HCVE did not differ in demographic variables, pre-LVAD co-morbidities, post-LVAD complications, NIH Stroke Scale at time of event, or anti-thrombotic regimen (ATR), except that events in those on no ATR were only ischemic. Patients with HCVEs were more likely to be discharged with no ATR (P=0.015). Mortality was significantly higher in patients with CVE (59.1% vs. 29.2% in those without CVE) but did not differ by CVE type. In patients with CVE, 57.1% of deaths were secondary to the CVE (ICVE 25%, HCVE 93.7%, P<0.001). Among BTT patients, only 14.6% with CVE underwent transplantation vs. 39.8% without CVE (P =0.002).

Conclusions: CVE remains a serious complication of LVAD support for advanced heart failure and is associated with increased mortality and lower rates of heart transplantation. Further investigations to identify risk factors for CVEs in LVAD patients and potential preventive measures including optimal ATRs are warranted.

Clinical outcomes with use of erythropoiesis stimulating agents in patients with the HeartMate II left ventricular assist device

OBJECTIVES

This study evaluated clinical outcomes associated with erythropoiesis stimulating agent (ESA) use in left ventricular assist devices (LVAD)-supported patients.

BACKGROUND

Use of ESAs in patients with LVADs may minimize blood transfusions and decrease allosensitization. ESAs increase thrombotic events, which is concerning because LVADs are sensitive to pump thrombosis (PT).

METHODS

We retrospectively reviewed 221 patients at our center who received a HeartMate II (Thoratec Corp., Pleasanton, California) LVAD between January 1, 2009 and June 6, 2013. Patients were divided into those who received ESAs during index admission (n = 121) and those who did not (n = 100). Suspected PT was defined as evidence of thrombus in the LVAD or severe hemolysis (lactate dehydrogenase >1,000 mg/dl or plasma-free hemoglobin >40 mg/dl). Outcomes were compared between cohorts using inverse probability-weighted analyses.

RESULTS

During a mean follow-up of 14.2 ± 11.9 months, suspected PT occurred in 37 patients (ESA 23%, no ESA 12%; p =0.03). The ESA cohort received ESAs 13.9 ± 60.9 days after LVAD implantation. At 180 days, event-free rates for suspected PT were ESA 78.6% versus no ESA 94.5% (p < 0.001). ESA use had higher rates of suspected PT (hazard ratio [HR]: 2.35; 95% confidence interval [CI]: 1.38 to 4.00; p = 0.002). For every 100-unit increase in cumulative ESA dosage, the hazard of suspected PT increased by 10% (HR: 1.10; 95% CI: 1.04 to 1.16; p < 0.001). After inverse probability weighting, ESA use was associated with a significantly higher rate of all-cause mortality (HR: 1.62; 95% CI: 1.12 to 2.33; p = 0.01).

CONCLUSIONS

ESA use in LVAD patients is associated with higher rates of suspected PT.

Rapid emergence of daptomycin resistance in clinical isolates of Corynebacterium striatum… a cautionary tale

The objective of this study was to investigate the observation of daptomycin resistance in Corynebacterium striatum, both in vivo and in vitro. We describe a case of C. striatum bacteremia in a patient with a left ventricular assist device (LVAD); the initial isolate recovered was daptomycin susceptible with a minimum inhibitory concentration (MIC) of 0.125 μg/ml. Two months later, and after daptomycin therapy, the individual became bacteremic with an isolate of C. striatum with a daptomycin MIC of >256 μg/ml. To study the prevalence of daptomycin resistance in C. striatum, clinical isolates of C. striatum were grown in broth culture containing daptomycin to investigate the emergence of resistance to this antimicrobial. Molecular typing was used to evaluate serial isolates from the index patient and the clinical isolates of C. striatum we assayed. In vitro analysis of isolates from the index patient and 7 of 11 additional C. striatum isolates exhibited the emergence of high-level daptomycin resistance, despite initially demonstrating low MICs to this antimicrobial agent. This phenotype was persistent even after serial subculture in the absence of daptomycin. Together, these data demonstrate that caution should be taken when using daptomycin to treat high-inoculum infections and/or infections of indwelling medical devices with C. striatum. To our knowledge, this is the first report characterizing the emergence of daptomycin resistance in C. striatum.

Slope of the anterior mitral valve leaflet: a new measurement of left ventricular unloading for left ventricular assist devices and systolic dysfunction

Left ventricular assist device (LVAD)-supported patients are evaluated routinely with use of transthoracic echocardiography. Values of left ventricular unloading in this unique patient population are needed to evaluate LVAD function and assist in patient follow-up. We introduce a new M-mode measurement, the slope of the anterior mitral valve leaflet (SLAM), and compare its efficacy with that of other standard echocardiographically evaluated values for left ventricular loading, including E/e' and pulmonary artery systolic pressures. Average SLAM values were determined retrospectively for cohorts of random, non-LVAD patients with moderately to severely impaired left ventricular ejection fraction (LVEF) (<0.35, n=60). In addition, pre- and post-LVAD implantation echocardiographic images of 81 patients were reviewed. The average SLAM in patients with an LVEF <0.35 was 11.6 cm/s (95% confidence interval, 10.4-12.8); SLAM had a moderately strong correlation with E/e' in these patients. Implantation of LVADs significantly increased the SLAM from 7.3 ± 2.44 to 14.7 ± 5.01 cm/s (n=42, P <0.0001). The LVAD-supported patients readmitted for exacerbation of congestive heart failure exhibited decreased SLAM from 12 ± 3.93 to 7.3 ± 3.5 cm/s (n=6, P=0.041). In addition, a cutpoint of 10 cm/s distinguished random patients with LVEF <0.35 from those in end-stage congestive heart failure (pre-LVAD) with an 88% sensitivity and a 55% specificity. Evaluating ventricular unloading in LVAD patients remains challenging. Our novel M-mode value correlates with echocardiographic values of left ventricular filling in patients with moderate-to-severe systolic function and dynamically improves with the ventricular unloading of an LVAD.

Utility of gene expression profiling score variability to predict clinical events in heart transplant recipients

BACKGROUND

Gene expression profiling test scores have primarily been used to identify heart transplant recipients who have a low probability of rejection at the time of surveillance testing. We hypothesized that the variability of gene expression profiling test scores within a patient may predict risk of future events of allograft dysfunction or death.

METHOD

Patients from the IMAGE study with rejection surveillance gene expression profiling tests performed at 1- to 6-month intervals were selected for this cohort study. Gene expression profiling score variability was defined as the standard deviation of an individual's cumulative test scores. Gene expression profiling ordinal score (range, 0-39), threshold score (binary value=1 if ordinal score ≥ 34), and score variability were studied in multivariate Cox regression models to predict future clinical events.

RESULTS

Race, age at time of transplantation, and time posttransplantation were significantly associated with future events in the univariate analysis. In the multivariate analyses, gene expression profiling score variability, but not ordinal scores or scores over threshold, was independently associated with future clinical events. The regression coefficient P values were <0.001, 0.46, and 0.773, for gene expression profiling variability, ordinal, and threshold scores, respectively. The hazard ratio for a 1 unit increase in variability was 1.76 (95% CI, 1.4-2.3).

DISCUSSION

The variability of a heart recipient's gene expression profiling test scores over time may provide prognostic utility. This information is independent of the probability of acute cellular rejection at the time of testing that is rendered from a single ordinal gene-expression profiling test score.

Deep RNA sequencing reveals dynamic regulation of myocardial noncoding RNAs in failing human heart and remodeling with mechanical circulatory support

BACKGROUND

Microarrays have been used extensively to profile transcriptome remodeling in failing human heart, although the genomic coverage provided is limited and fails to provide a detailed picture of the myocardial transcriptome landscape. Here, we describe sequencing-based transcriptome profiling, providing comprehensive analysis of myocardial mRNA, microRNA (miRNA), and long noncoding RNA (lncRNA) expression in failing human heart before and after mechanical support with a left ventricular (LV) assist device (LVAD).

METHODS AND RESULTS

Deep sequencing of RNA isolated from paired nonischemic (NICM; n=8) and ischemic (ICM; n=8) human failing LV samples collected before and after LVAD and from nonfailing human LV (n=8) was conducted. These analyses revealed high abundance of mRNA (37%) and lncRNA (71%) of mitochondrial origin. miRNASeq revealed 160 and 147 differentially expressed miRNAs in ICM and NICM, respectively, compared with nonfailing LV. Among these, only 2 (ICM) and 5 (NICM) miRNAs are normalized with LVAD. RNASeq detected 18 480, including 113 novel, lncRNAs in human LV. Among the 679 (ICM) and 570 (NICM) lncRNAs differentially expressed with heart failure, ≈10% are improved or normalized with LVAD. In addition, the expression signature of lncRNAs, but not miRNAs or mRNAs, distinguishes ICM from NICM. Further analysis suggests that cis-gene regulation represents a major mechanism of action of human cardiac lncRNAs.

CONCLUSIONS

The myocardial transcriptome is dynamically regulated in advanced heart failure and after LVAD support. The expression profiles of lncRNAs, but not mRNAs or miRNAs, can discriminate failing hearts of different pathologies and are markedly altered in response to LVAD support. These results suggest an important role for lncRNAs in the pathogenesis of heart failure and in reverse remodeling observed with mechanical support.

HeartWare and HeartMate II left ventricular assist devices as bridge to transplantation: a comparative analysis

BACKGROUND

The purpose of this study is to comparatively analyze outcomes of heart transplant patients bridged to transplantation with HeartWare (HW-VAD) versus HeartMate II (HMII-VAD) left ventricular assist devices.

METHODS

The United Network for Organ Sharing Database was reviewed to identify first-time heart transplant recipients who were bridged to transplantation with either HW-VAD (n=141) or HMII-VAD (n=1824) from January 2009 through July 2012.

RESULTS

Recipients of HW-VAD had a higher proportion of female patients (27.0% versus 18.9%; p=0.019), a lower body surface area (2.01±0.25 m2 versus 2.06±0.25 m2; p=0.035), and a trend toward a higher peak percentage of panel reactive antibody against human leukocyte class I antigens (40.4%±32.8% versus 33.0%±30.4%; p=0.070). Pretransplantation recipient cardiac index (2.33±0.66 L⋅min(-1)⋅m(-2) versus 2.33±0.68 L⋅min(-1)⋅m(-2)), serum creatinine (1.21±0.43 mg/dL versus 1.26±0.57 mg/dL), and total bilirubin (1.34±3.45 mg/dL versus 1.06±1.84 mg/dL) were comparable between the two groups (p>0.05 for all comparisons). After transplantation, there were no significant differences in freedom from rejection or freedom from cardiac allograft vasculopathy. Posttransplant graft survival rates were similar between the HW-VAD group and the HMII-VAD group at 1, 2, and 3 years (88.4% versus 87.8%, 79.9% versus 83.8%, and 77.4% versus 79.9%, respectively; p=0.843).

CONCLUSIONS

These findings suggest similar hemodynamic unloading, pretransplant end-organ function, and posttransplant outcomes in patients bridged to transplantation with both the HW-VAD and HMII-VAD.