Contemporary Sex-Based Outcomes after Orthotopic Heart Transplantation for Patients Bridged with Newer Generation Left Ventricular Assist Devices

Abstract

Prior work has shown that female sex is associated with a significantly increased risk of death after orthotopic heart transplantation (OHT). The impact of sex on outcomes of OHT following bridging with newer generation durable left ventricular assist devices (LVADs) is less established. This study evaluated sex-based differences in OHT outcomes in recipients bridged with a HeartMate III (HM3) or HeartWare (HVAD) LVAD. The United Network for Organ Sharing (UNOS) database was queried to study OHT recipients bridged with a newer generation (HM3 or HVAD) LVAD between 2010 and 2018. The primary outcome was mortality at 1-year follow-up. Secondary outcomes included rates of posttransplant complications. Propensity score matching was utilized to adjust for residual bias among male and female recipients. Cox multivariable analysis was employed to determine independent predictors of the primary outcomes of death at 30 days, 90 days, and 1 year following OHT. A total of 3,010 patients (76.7% male) bridged with newer generation LVADs underwent OHT. Male patients were significantly older (53.0 vs 49.7 years, p<0.001) and had more comorbidities. Males were also more likely to require dialysis post-transplant (13.6% vs 9%, p<0.001). After adjusting for relevant covariates, both age and heart failure etiology, but not sex, were independent predictors of mortality at 30 days, 90 days, and 1 year. Propensity matching resulted in a well-matched subset of 656 patients. In the matched cohorts, sex did not impact post-transplant outcomes, including renal failure, cerebrovascular events, allograft rejection, functional status, or mortality (all p>0.05). Survival at 1 year after OHT was 94.6% in males and 96.9% in females for patients bridged with newer generation LVADs (p=0.45). In our study of 3,010 OHT recipients, we found that matched females bridged with newer generation HVAD or HM3 LVADs have comparable post-transplant outcomes. Furthermore, survival at 1-year follow-up was not impacted by sex and instead was driven by well-established risk factors including increasing age, worse pre-operative renal function, and heart failure etiology. These data suggest considerable progress in mitigating sex differences in heart failure outcomes in the modern era.