Age-Based Outcomes After Surgical Aortic Valve Replacement With Bioprosthetic Versus Mechanical Valves

Recommendations for prosthesis type in older patients who underwent surgical aortic valve replacement (SAVR) are established, albeit undervalidated. The purpose of this study is to compare outcomes after bioprosthetic versus mechanical SAVR across various age groups. This was a retrospective study using an institutional SAVR database. All patients who underwent isolated SAVR were compared across valve types and age strata (<65 years, 65 to 75 years, >75 years). Patients who underwent concomitant operations, aortic root interventions, or previous aortic valve replacement were excluded. Objective survival and aortic valve reinterventions were compared. Kaplan-Meier survival estimation and multivariate regression were performed. A total of 1,847 patients underwent SAVR from 2010 to 2023. A total of 1,452 patients (78.6%) received bioprosthetic valves, whereas 395 (21.4%) received mechanical valves. Of those who received bioprosthetic valves, 349 (24.0%) were aged <65 years, 627 (43.2%) were 65 to 75 years, and 476 (32.8%%) were older than 75 years. For patients who received mechanical valves, 308 (78.0%) were aged <65 years, 84 (21.3%) were between 65 and 75 years, and 3 (0.7%) were >75 years. The median follow-up in the total cohort was 6.2 (2.6 to 8.9) years. No statistically significant differences were observed in early-term Kaplan-Meier survival estimates between SAVR valve types in all age groups. However, the cumulative incidence estimates of aortic valve reintervention were significantly higher in patients aged under 65 years who received bioprosthetic than those who received mechanical valves, with 5-year reintervention rates of 5.8% and 3.1%, respectively (p = 0.002). On competing risk analysis for valve reintervention, bioprosthetic valves were significantly associated with an increased hazard of aortic valve reintervention (hazard ratio 3.35, 95% confidence interval 1.73 to 6.49, p <0.001). In conclusion, SAVR with bioprosthetic valves (particularly, in patients aged <65 years) was comparable in survival to mechanical valve SAVR but significantly associated with increased valve reintervention rates.