Increasing wait-time mortality for severe aortic stenosis: a population-level study of the transition in practice from surgical aortic valve replacement to transcatheter aortic valve replacement

Background — Transcatheter aortic valve replacement (TAVR) has emerged as a reasonable alternative to surgical aortic valve replacement (SAVR) for patients with severe aortic stenosis (AS). There is limited data on temporal trends in wait-times and access to care for patients with AS, irrespective of treatment modality. We sought to investigate the trends in wait-times for the treatment (either SAVR or TAVR) of AS in Ontario, Canada, and to understand the drivers of wait-list mortality and hospitalization due to heart failure.

Methods — In this population-level retrospective cohort study, we identified patients from April 1, 2012, to March 31, 2018, who were referred for treatment of symptomatic severe AS awaiting either SAVR or TAVR. The primary outcome was the median total wait-time from referral date to either SAVR or TAVR procedure. Primary clinical outcomes were all-cause mortality and heart failure-related hospitalizations while on the wait-list.

Results — The referral cohort consisted of a total of 22 876 referrals for aortic valve replacement, with (N=8098) TAVR and (N=14 778) SAVR referrals. The mean and median wait times for the overall AVR cohort were 87 and 59 days, respectively. The TAVR subcohort had longer wait-times (median 84 days) compared with the SAVR subcohort (median 50 days). Year over year, there was a statistically significant an increase in wait-times (P<0.001) for the overall AS cohort as well as each of the TAVR (P<0.0001) and SAVR (P<0.0001) subgroups. Wait-time mortality was 2.5% (TAVR 5.2% and SAVR 1.05%), while the cumulative probability of heart failure hospitalization was 3.6% (TAVR 7.7% and SAVR 1.3%).

Conclusions — In patients with severe symptomatic AS awaiting aortic valve replacement, there has been a trend of increasing wait times for both SAVR and TAVR. This was associated with increasing mortality and hospitalizations related to heart failure while on the wait-list.