Sex-Related Differences in Use and Outcomes of Left Ventricular Assist Devices as Bridge to Transplantation

Objectives: This study examined sex-related differences in use and outcomes of continuous-flow left ventricular assist devices (CF-LVADs) among individuals awaiting heart transplantation using the United Network for Organ Sharing registry. Background: Advanced therapies for heart failure including CF-LVADs remain underused in women. There have been contradictory results regarding sex-specific outcomes. Many studies have been limited by small sample sizes or included pulsatile-flow devices. Methods: De-identified patient-level data were obtained from the United Network for Organ Sharing database. The database was queried to identify adult patients (≥18 years of age) who required mechanical circulatory support with HeartWare HVAD (Medtronic, Minneapolis, Minnesota), HeartMate II (Abbott, Lake Bluff, Illinois), or HeartMate 3 (Abbott) as bridge to heart transplantation between 2008 and 2018. Each patient was assigned a propensity score. The primary outcomes of interest were rates of transplantation and death. Results: A total of 13,305 patients (2,771 women, 20.8%) received support with CF-LVAD in the study period. There were significant sex disparities in CF-LVAD use in listed patients (29.9% men vs. 18.9% women in 2017). Female patients receiving CF-LVAD support had lower chances of heart transplantation (55.1% vs. 67.5%), increased risk of waitlist mortality (7.0% vs. 4.2%), and delisting for worsening clinical status (8.5% vs. 4.7%) at 2 years post-implantation (all p < 0.001). After adjusting for device type, sex was still a significant predictor of waitlist mortality (hazard ratio: 1.51; p < 0.001). Conclusions: Durable mechanical circulatory support with CF-LVADs remains underused in women. When matched with similar male control subjects, women experienced higher mortality and lower rates of heart transplantation.