Can prosthesis type influence the recurrence of infective endocarditis after surgery for native valve endocarditis? A propensity weighted comparison

OBJECTIVES: Our goal was to investigate whether the incidence of valve-related adverse events might be different depending on the valve substitute after valve replacement for left-sided native valve endocarditis.METHODS: We assessed the long-term freedom from recurrence, reoperation and survival of 395 patients who had valve replacements for native valve endocarditis (314 mechanical vs 81 biological). Age <18 years, reoperation, prosthetic endocarditis, right valve involvement, valve repair and homograft implants were the main exclusion criteria. The balance between the 2 groups was addressed by weighting the results on the inverse of the propensity score.RESULTS: After inverse probability of treatment weighting (IPTW), freedom from recurrence of infective endocarditis was not significantly different (mechanical 84.1 +/- 3.2% vs 50.6 +/- 21.7%; P = 0.29) nor was freedom from reoperation different (mechanical 85.7 +/- 3.1% vs biological 50.9 +/- 21.9%; P = 0.29). Excluding competing deaths, patients receiving a bioprosthesis had a similar subdistribution hazard of the above end points compared to recipients of a mechanical valve [recurrence IPTW: hazard ratio (HR) 1.631, 95% confidence interval (CI) 0.756-3.516; P = 0.21; reoperation IPTW-HR 1.737, 95% CI 0.780-3.870; P = 0.18]. Mechanical valves were associated with improved long-term survival (34.9 +/- 5.8% vs 10.5 +/- 7.4% at 30 years; P = 0.0009; in particular: aortic valve subgroup 41.6 +/- 9.3% vs 10.1 +/- 8.2%; P < 0.0001), although the hazard of cardiovascular mortality did not favour either valve type (IPTW: HR 1.361, 95% CI 0.771-2.404; P = 0.29).CONCLUSIONS: Our analysis showed a clinical trend in favour of mechanical valves as valve substitutes for native valve endocarditis, especially in the aortic position. In view of long-term freedom from adverse events, the choice of the valve type should be tailored according to patient characteristics and specific clinical conditions.