Waitlist and transplant outcomes in heart transplant candidates bridged with temporary endovascular right ventricular assist devices.

BACKGROUND: Advances in mechanical circulatory support and changes in allocation policy have shifted waitlisting practices for heart transplantation (HT) in the United States. This analysis reports waitlist and transplant outcomes among HT candidates bridged with temporary endovascular right ventricular assist devices (tRVADs). METHODS: Patients awaiting HT from 2008 to 2022 in the United Network of Organ Sharing registry were grouped by the presence of tRVAD while waitlisted and propensity matched. Waitlist outcomes were HT and a competing outcome of death/deterioration requiring waitlist inactivation. Competing-risks regression was used to model waitlist outcomes. Subanalyses were performed to compare waitlist outcomes among patients with durable and temporary left ventricular assist devices (LVADs) with and without concomitant tRVADs. One-year posttransplant mortality was estimated using Kaplan-Meier analysis. RESULTS: Of 41,507 HT candidates, 133 (0.3%) had tRVADs. After propensity matching, patients with tRVAD had a similar likelihood of HT and an elevated hazard for death/deterioration (hazard ratio 2.2, 95% confidence interval 1.4-3.2, p < 0.001) compared to those without tRVAD. Most patients with tRVAD (84%) had concomitant LVADs. tRVAD was associated with an elevated risk for deterioration/death among those with temporary LVADs but not durable LVADs. For patients undergoing HT, tRVAD was associated with an increased risk for 1-year mortality compared to propensity-matched recipients. CONCLUSIONS: Bridging with tRVAD is uncommon and primarily used in patients requiring biventricular support. tRVADs are associated with waitlist inactivation or death, particularly with concomitant temporary LVAD support. As temporary devices are increasingly used as a bridge to HT, outcomes of patients with tRVADs should inform future allocation policy, particularly for candidates with biventricular failure.

Effects of Percutaneous LVAD Support on Right Ventricular Load and Adaptation.

Both operative and hemodynamic mechanisms have been implicated in right heart failure (RHF) following surgical left ventricular assist device (LVAD) implantation. We investigated the effects of percutaneous LVAD (pLVAD; Impella®, Abiomed) support on right ventricular (RV) load and adaptation. We reviewed all patients receiving a pLVAD for cardiogenic shock at our institution between July 2014 and April 2017, including only those with pre- and post-pLVAD invasive hemodynamic measurements. Hemodynamic data was recorded immediately prior to pLVAD implantation and up to 96 h post-implantation. Twenty-five patients were included. Cardiac output increased progressively during pLVAD support. PAWP improved early post-pLVAD but did not further improve during continued support. Markers of RV adaptation (right ventricular stroke work index, right atrial pressure (RAP), and RAP to pulmonary artery wedge pressure ratio (RAP:PAWP)) were unchanged acutely implant but progressively improved during continued pLVAD support. Total RV load (pulmonary effective arterial elastance; EA) and resistive RV load (pulmonary vascular resistance; PVR) both declined progressively. The relationship between RV load and RV adaptation (EA/RAP and EA/RAP:PAWP) was constant throughout. Median vasoactive-inotrope score declined after pLVAD placement and continued to decline throughout support. Percutaneous LVAD support in patients with cardiogenic shock did not acutely worsen RV adaptation, in contrast to previously described hemodynamic effects of surgically implanted durable LVADs. Further, RV load progressively declined during support, and the noted RV adaptation improvement was load-dependent as depicted by constant EA/RA and EA/RAP:PAWP relationships. These findings further implicate the operative changes associated with surgical LVAD implantation in early RHF following durable LVAD.