Early and Midterm Outcomes following Aortic Valve Replacement with Mechanical versus Bioprosthetic Valves in Patients aged 50 to 70 Years

Abstract

Objectives: To compare 7-year survival and freedom from reoperation, as well as early clinical and hemodynamic outcomes, after surgical aortic valve replacement (SAVR) with mechanical or bioprosthetic valves in patients aged 50-70 years. Methods: single-center retrospective cohort study including adults aged 50-70 years who underwent SAVR in 2012 with a mechanical or bioprosthetic valve. Median follow-up was 7 years. Univariable analyses were performed using Kaplan-Meier curves and Log-Rank tests for survival and freedom from reoperation analyses. Multivariable time-to-event analyses were conducted using Cox Regression. Results: Of a total of 193 patients, 76 (39.4%) received mechanical valves and 117 (60.6%) received bioprosthetic valves. Using a forward stepwise Cox regression, prosthesis type was not retained by the model, but a trend for better survival was found when adjusting only for EuroSCORE II (HR: 0.35, 95%CI: 0.12-1.02, p=0.054). Freedom from reoperation at 7 years was higher in the mechanical group (100% vs 95,5%, Log-Rank=0.076). Median EuroSCORE II was higher in the mechanical group (2.52% vs 1.95%, p=0.06), as was early mortality (2.6% vs 7.9%). After adjusting for EuroSCORE II, there was no significant difference in early mortality (OR=2,32 [0,515-10,496]). Regarding hemodynamic performance at follow-up echocardiogram, there were no differences other than left ventricular mass regression, which was not as pronounced in the mechanical group (-12% vs -21%, p=0.002). Conclusion: Mechanical and bioprosthetic aortic valves prostheses were comparable in terms of mid-term survival and early hemodynamic performance, in the 50-70 age group. Further prospective and larger studies are needed to provide evidence-based recommendations on this topic.