Characteristics and outcomes of left ventricular assist device recipients transplanted before and after the new donor heart allocation system.

BACKGROUND

Concerns about the impact of the new donor heart allocation system on posttransplant outcomes have emerged after its implementation. We sought to evaluate the characteristics and outcomes of left ventricular assist device (LVAD) recipients transplanted before and after the implantation of the new policy on October 18, 2018.

METHODS

Data on bridge to transplantation of adult patients with LVAD between January 2015 and October 2021, with durable LVAD as a (BTT), was queried from the United Network of Organ Sharing (UNOS) registry. The main outcomes were 30-day all-cause mortality, 30-day fatal graft failure, 1-year all-cause mortality, treated acute rejection at 1 year and renal replacement therapy (RRT) for acute renal failure.

RESULTS

In our study, 7096 patients met the inclusion criteria including 2435 in the new allocation system. The transplanted patients in the new allocation system era had older donor age, longer ischemic time, and higher proportion of newer generation LVADs. Adjusted 30-day all-cause mortality was significantly lower for LVAD recipients in the new allocation system era (2.5% vs. 3.6%; sub-hazard ratio [SHR] 0.36, 95% Confidence intervals [CI] 0.27-0.48, p < 0.001) without differences in the risk of fatal graft failure and 1-year mortality (7.8% vs. 9.6%). Significantly lower adjusted 30-day mortality with HVAD and HM3 devices than HM2 in the new allocation system era was found, without differences in 1-year mortality. Acute allograft rejection requiring treatment was significantly lower (Odds Ratio 0.78, 95% CI 0.65-0.94, p = 0.01), whereas a trend toward higher risk of renal failure requiring RRT was identified.

CONCLUSIONS

Despite changing donor characteristics and longer ischemic times, posttransplant outcomes in LVAD recipients have not worsened with the implementation of the new allocation system and this finding is related to the use of newer generation continuous flow LVADs.