Background: Infective endocarditis(IE) is a serious disease and in many cases surgery is necessary. Whether the type of prosthesis implanted for aortic valve replacement(AVR) for IE impacts patient survival is a matter of debate. The aim of the present study is to quantify differences in long-term survival, recurrence of endocarditis AVR for IE according to prosthesis type among patients aged 40 to 65 years. Methods: This was an analysis of the INFECT-REGISTRY. Overall, 4365 patients were diagnosed and operated on for IE from 2000 to 2021. Of these, 549 aged between 40 and 65 years underwent AVR. 268(48.8%) received mechanical prostheses, and 281(51.2%) biological ones. Confounders were adjusted using optimal full matching propensity score. Results: A significant trend in reduction of implantation of mechanical vs biological prostheses was observed during the study period(p<0.0001). Long-term survival was significantly higher among patients receiving a mechanical prosthesis than those receiving a biological prosthesis (hazard ratio [HR] 0.546,95%CI: 0.322-0.926, p=0.025). Mechanical prostheses were significantly associated with less recurrent endocarditis after AVR (HR 0.268,95%CI:0.077-0.933,p=0.039).Conclusions: The present analysis of the INFECT-REGISTRY shows increased survival and reduced recurrence of endocarditis after mechanical aortic valve prosthesis implant for IE in middle-aged patients.
