Heart Transplant Outcomes in Patients with Urgent Listing Priority in Canada

Purpose 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. Methods 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. Results 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). Conclusion 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.