Impact of Transcatheter Aortic Valve Durability on Life Expectancy in Low-Risk Patients With Severe Aortic Stenosis

Abstract

Background:

Recent clinical trial results showed that transcatheter aortic valve replacement (TAVR) is noninferior and may be superior to surgical aortic valve replacement (SAVR) for mortality, stroke, and rehospitalization. However, the impact of transcatheter valve durability remains uncertain.

Methods:

Discrete event simulation was used to model hypothetical scenarios of TAVR versus SAVR durability in which TAVR failure times were varied to determine the impact of TAVR valve durability on life expectancy in a cohort of low-risk patients similar to those in recent trials. Discrete event simulation modeling was used to estimate the tradeoff between a less invasive procedure with unknown valve durability (TAVR) and that of a more invasive procedure with known durability (SAVR). Standardized differences were calculated, and a difference >0.10 was considered clinically significant. In the base-case analysis, patients with structural valve deterioration requiring reoperation were assumed to undergo a valve-in-valve TAVR procedure. A sensitivity analysis was conducted to determine the impact of TAVR valve durability on life expectancy in younger age groups (40, 50, and 60 years).

Results:

Our cohort consisted of patients with aortic stenosis at low surgical risk with a mean age of 73.4±5.9 years. In the base-case scenario, the standardized difference in life expectancy was <0.10 between TAVR and SAVR until transcatheter valve prosthesis failure time was 70% shorter than that of surgical prostheses. At a transcatheter valve failure time <30% compared with surgical valves, SAVR was the preferred option. In younger patients, life expectancy was reduced when TAVR durability was 30%, 40%, and 50% shorter than that of surgical valves in 40-, 50-, and 60-year-old patients, respectively.

Conclusions:

According to our simulation models, the durability of TAVR valves must be 70% shorter than that of surgical valves to result in reduced life expectancy in patients with demographics similar to those of recent trials. However, in younger patients, this threshold for TAVR valve durability was substantially higher. These findings suggest that durability concerns should not influence the initial treatment decision concerning TAVR versus SAVR in older low-risk patients on the basis of current evidence supporting TAVR valve durability. However, in younger low-risk patients, valve durability must be weighed against other patient factors such as life expectancy.