Surgery for Complex vs. Simple Native Left-Sided Endocarditis: Insights from an Extended Follow-Up on Survival, Recurrent Infection, and Valve Durability

<b>Background/Objectives</b>: We compared short- and long-term outcomes of patients with native left-sided infective endocarditis (IE) confined to the valve leaflet ("simple") versus those with perivalvular extension ("complex") over two decades. <b>Methods</b>: From 2005 to 2024, 177 patients (mean age 59.6 ± 13.8 years, 71.8% male) underwent surgery for IE. Patients were classified as having simple (<i>n</i> = 129) or complex IE (<i>n</i> = 48) based on imaging and intraoperative findings. Mean follow-up was 86.5 ± 63.3 months (range: 2-232 months). Outcomes included operative and late mortality, recurrent infection, and reoperation. <b>Results</b>: Complex IE was associated with worse preoperative status, longer ICU stays, and mechanical ventilation times. Predictors of early mortality included critical preoperative state (OR 6.35, <i>p</i> = 0.001), chronic renal failure/dialysis (OR 3.01, <i>p</i> = 0.05), and staphylococcal IE (OR 5.62, <i>p</i> = 0.002) but not perivalvular extension. Overall survival at 1, 5, 10, 15, and 20 years was 83%, 74.2%, 59.9%, 51.3%, and 40.7%, with no significant difference between groups (<i>p</i> = 0.18). Female gender (HR 1.93, <i>p</i> = 0.04) and chronic renal failure (HR 3.5, <i>p</i> < 0.01) predicted late mortality. Freedom from re-endocarditis and reoperation d/t relapse of endocarditis was 94.2% and 97.3%, respectively. Freedom from re-intervention d/t structural valve degeneration was 92.1% at 10 years. Repair was performed in 28.2% of cases involving the mitral valve, with 93.1% freedom from reoperation. <b>Conclusions</b>: Surgery for complex IE is not an independent risk factor for long-term mortality. Rates of recurrent endocarditis and reoperation are remarkably low. Excellent durability of bioprostheses and mitral repair was demonstrated.