Derrick Y Tam1, Harindra C Wijeysundera2, David Naimark3, Mario Gaudino4, John G Webb5, David J Cohen6, Stephen E Fremes1. 1. Division of Cardiac Surgery, Department of Surgery, Schulich Heart Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Canada; Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Canada. 2. Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Canada; ICES, Toronto, Canada; Division of Cardiology, Department of Medicine, Schulich Heart Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Canada. 3. Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Canada. 4. Department of Cardiothoracic Surgery, Weill Cornell Medical College, New York, NY. 5. Center for Heart Valve Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada. 6. Kansas City, MO.
Abstract
Background: Recent clinical trial results showed that transcatheter aortic valve replacement (TAVR) is non-inferior 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 (DES) was used to model hypothetical scenarios of TAVR versus SAVR durability where 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. DES 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 low surgical risk aortic stenosis patients with mean age 73.4±5.9 years. In the base case scenario, standardized difference in life expectancy was <0.10 between TAVR and SAVR until transcatheter valve prosthesis failure time was 70% shorter than surgical prostheses. At a transcatheter valve failure time <30% compared to surgical valves, SAVR was the preferred option. In younger patients, life expectancy was reduced when TAVR durability was 30%, 40%, and 50% shorter than surgical valves in 40, 50, and 60-year-old patients respectively. Conclusions: Based on 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 similar demographics to 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 regarding TAVR versus SAVR in older low risk patients based on 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.
Background: Recent clinical trial results showed that transcatheter aortic valve replacement (TAVR) is non-inferior 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 (DES) was used to model hypothetical scenarios of TAVR versus SAVR durability where 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. DES 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 low surgical risk aortic stenosispatients with mean age 73.4±5.9 years. In the base case scenario, standardized difference in life expectancy was <0.10 between TAVR and SAVR until transcatheter valve prosthesis failure time was 70% shorter than surgical prostheses. At a transcatheter valve failure time <30% compared to surgical valves, SAVR was the preferred option. In younger patients, life expectancy was reduced when TAVR durability was 30%, 40%, and 50% shorter than surgical valves in 40, 50, and 60-year-old patients respectively. Conclusions: Based on 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 similar demographics to 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 regarding TAVR versus SAVR in older low risk patients based on 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.