Heart Transplant Outcomes in Patients with Urgent Listing Priority in Canada

Abstract

<h3>Purpose</h3> Patients waiting for heart transplant (HT) urgently in Canada are listed status 4, defined as mechanically ventilated on inotropes, dependent on temporary mechanical circulatory support (T-MCS), or with durable left ventricular assist device (LVAD) complications. Our objectives were to describe wait time and survival to HT for status 4 patients and describe their post-HT outcomes. <h3>Methods</h3> We conducted a retrospective review of consecutive adults (≥ 18 y) listed for HT using the Canadian Blood Services database and evaluated post-HT outcomes in patients transplanted status 4 at 5 centers between 2013-2019. We evaluated the incidence of HT and death/delisting using competing risk analyses. Post-HT survival was assessed using Kaplan-Meier survival estimates and compared using the logrank test. <h3>Results</h3> Of 204 listed status 4, 81% survived to HT. Time to HT for status 4 patients was 24 (IQR 8-101) days and significantly shorter compared to all listing groups except 3.5 (Fig). Adjusting for age, sex, blood group, height and weight, patients listed status 4 were more likely to survive to HT (HR 1.37, 95% CI: 1.08-1.74) and equally likely to die or be delisted (HR 1.55, 95% CI: 0.90-2.69), Fig). The urgent indication for 62 patients transplanted status 4 was: T-MCS (48%), LVAD complication (40%), refractory ventricular arrhythmia not on T-MCS (6%), and other (5%). Of 30 patients on T-MCS pre-HT, 17% were supported with IABP, 30% with VA-ECMO, and 53% with CentriMag. 30-day and 1-year survival were 95% for the overall cohort. Over 2.9 (IQR 1.6-4.7) years of follow up, cumulative post-HT survival was comparable between patients transplanted from VA-ECMO vs. other status 4 indications, and patients transplanted from any T-MCS vs. no T-MCS (p=0.13, p=0.69 respectively). <h3>Conclusion</h3> Patients listed urgent priority status 4 have acceptable wait times to HT and are not more likely to die waiting compared to other listing groups. Patients transplanted status 4, including those bridged with T-MCS, achieve good short-term post-HT survival.