Risk of severe primary graft dysfunction in patients bridged to heart transplantation with continuous-flow left ventricular assist devices.

BACKGROUND: Primary graft dysfunction (PGD) remains a significant cause of post-transplant morbidity and mortality. The exact mechanism and risk factors for this phenomenon remain unknown in the contemporary era.

METHODS: In this study we reviewed adult patients undergoing heart transplantation (HT) at our institution between 2009 and 2017. Severe PGD was defined as the need for mechanical circulatory support (MCS) within the first 24 hours after HT. Multivariate logistic regression analysis was used to identify risk factors for severe PGD, focusing on those bridged to transplant (BTT) with a continuous-flow left ventricular assist device (CF-LVAD).

RESULTS: Fifty-six of 480 (11.7%) HT patients experienced severe PGD. Eighty percent of the severe PGD patients were BTT with a CF-LVAD (odds ratio [OR] 3.86, 95% confidence interval [CI] 1.94 to 7.68, p < 0.001). Among the BTT patients, significant associations between >1 year of CF-LVAD support (OR 2.48, 95% CI 1.14 to 5.40, p = 0.022), pre-HT creatinine (OR 3.35, 95% CI 1.42 to 7.92, p = 0.006), elevated central venous pressure/pulmonary capillary wedge pressure (CVP/PCWP) ratio (OR 3.32, 95% CI 1.04 to 10.60, p = 0.043), use of amiodarone before HT (OR 2.69, 95% CI 1.20 to 6.20, p = 0.022), and severe PGD were identified. RADIAL score did not accurately predict severe PGD in this contemporary cohort. Those patients who developed severe PGD had decreased 1-year post-transplant survival (78.3% vs 91.8%, p = 0.007).

CONCLUSIONS: Use of CF-LVAD as BTT is associated with an increased risk of severe PGD. Increased time on device support, renal dysfunction, right ventricular dysfunction as assessed by CVP/PCWP ratio, and pre-transplant amiodarone may identify those patients at high risk. Further research is warranted focusing on optimal timing of device implantation and transplantation, as well as the underlying mechanisms of PGD.