Clinical outcome after bioprosthetic aortic root replacement: A Meta-Analysis and Microsimulation model

Background and aim of the study This study aims to provide an overview of clinical outcome after bioprosthetic aortic root replacement and lifetime event-risk estimates of mortality and valve-related events, and the potential effect of type of prosthesis used. Methods A systematic literature search was conducted between January 2000 and August 2019. Inclusion criteria: aortic root replacement in adults. Data were pooled by inverse-variance weighting and entered a microsimulation model to calculate lifetime event-risk and (event-free) life expectancy. Results Of 2,106 publications, 31 were included (N = 5,227 patients, 74% stentless valves). Mean age was 65.4 years (74% male). Pooled early mortality was 5.5% (95% CI: 4.3-7.2%). During follow-up (mean 4.1 years, total 22.706 patient-years), late mortality was 4.8%/patient-year and reoperation 0.9%/patient-year. Linearized-occurrence-rates for thromboembolism, endocarditis, and hemorrhagic events:1.2; 0.9 and 0.5 %/patient-year; no significant difference between stented and stentless prosthesis. Translating into a 60-year-old patient, an estimated life expectancy of 14 years (general population: 22 years) and lifetime risks of thromboembolism, endocarditis and reintervention of 21%, 13%, and 8%, respectively is expected. Conclusions The study shows impaired survival and a notable lifetime risk of valve-related events after bioprosthetic aortic root replacement. The risk of thromboembolism is prominent, especially during earlier follow-up, suggesting higher risk of thromboembolism early after operation. Type of prosthesis, stented or stentless, is not associated with higher valve-related events. Moreover, this study could be used as a benchmark to compare outcome with other aortic root replacement procedures.