Transcatheter aortic valve implantation (TAVI) is a minimally invasive therapy for patients with severe aortic stenosis. In Ontario, increases in capacity have not matched the rapidly growing demand for TAVI. As a result, wait-times for TAVI in Ontario exceed guideline targets, and waitlist morbidity is consequently considerable. The objective of this study was to evaluate the clinical implications of expanded TAVI capacity.

We performed a decision analysis using an open, parallel, resource-constrained microsimulation from the Ontario Ministry of Health perspective. Simulated patients entered the model during a five-year period, and stayed in the model until death or end of time horizon. Referral numbers increased annually according to historical trends. The additional capacity required to meet wait-time benchmarks in five years was identified by a sensitivity analysis. Clinical outcomes were estimated for three strategies: (i) current practice with annual capacity increases; (ii) accelerated capacity increases achieving benchmarks after five years; and (iii) no increase in capacity. Outcomes included pre-procedural mortality and hospitalization, and the proportion of TAVIs performed urgently.

Over the five years, we estimated that TAVI referrals would increase from 1,980/year to 3,268/year. To achieve wait-time benchmarks during this period, TAVI rates must be increased by approximately 6.3 percent annually, for a total of 12,220 procedures performed over the 5 years. Compared to current TAVI capacity increase, an accelerated increase in capacity achieving wait-time benchmarks led to a reduction of 29.36 percent in pre-procedural deaths, as well as 26.38 percent in pre-procedural hospitalizations and 30.31 percent in nonelective TAVIs.

Increases in TAVI capacity in Ontario must be accelerated to meet wait-time benchmarks in five years. Expansion of TAVI care in Ontario would be associated with considerable reductions in mortality and hospitalizations. Without intervention, both wait-times and adverse outcomes on the waitlist are expected to continue increasing. Prioritization strategies to mitigate the adverse effects of long wait-times must be used until wait-time targets are achieved.