Aortic valve replacement for endocarditis: Determinants of early and late outcome

Background and aim of the study: The study aim was to determine risk factor s for operative mortality, recurrent infection, reoperation and long-term s urvival following aortic valve replacement (AVR) for infective endocarditis . Methods: Between 1973 and 1997, 109 patients (91 male, 18 female, mean age 52.6 years) underwent isolated AVR for infective endocarditis,in our unit. Native valve endocarditis was present in 89 (81.6%) and prosthetic valve en docarditis in 20 (18.4%). Active culture-positive endocarditis was present in 53 (48.6%). Preoperatively, 99 patients (90.8%) were in NYHA classes III and IV. Indications for surgery included cardiac failure in 41 patients, v alvular dysfunction in 38, vegetations in 18, sepsis in seven, abscess in s ix and embolism in four. Mechanical valves were implanted in 69 patients (6 3.3%) and bioprostheses in 40 (36.7%), including a homograft in 19 (17.4%). Follow up was complete (mean 5.8 years; range: 0-23.8 years; total 633.5 p atient-years). Results: The operative mortality was 10.1% (11 deaths). At ten years, freed om from recurrent infection was 94.2%, and freedom from reoperation 83.6%. Biological valve and younger age were significant adverse parameters for fr eedom from reoperation (p = 0.01 and p = 0.01). There have been 21 late dea ths, 15 due to cardiac causes. Kaplan-Meier survival, including operative m ortality, at five and ten years was 77.4% and 68.0%, respectively. On Cox p roportional hazards regression, Staphylococcus aureus infection (p = 0.008) and older age (p = 0.04) were independent adverse predictors of survival. Conclusion: AVR for endocarditis carries a relatively high operative mortal ity, but can result in a satisfactory freedom from recurrent infection, reo peration and long-term survival. Analysis of our series demonstrates that i mplantation of a biological valve limits the freedom from reoperation and t hat infection by Staph. aureus reduces the probability of longterm survival .