Aortic cross-clamp time and cardiopulmonary bypass time: prognostic implications in patients operated on for infective endocarditis

OBJECTIVES: Prolonged aortic cross-clamp (XCT) and cardiopulmonary bypass time (CPBT) are associated with increased morbidity and mortality following cardiac surgery. The aim of this study was to assess the predictors of mortality and other severe postoperative complications in patients undergoing surgery for infective endocarditis (IE), focusing in particular on the role of prolonged XCT and CPBT. METHODS: A retrospective single-centre study was conducted from January 2000 to January 2017, including all patients undergoing valvular surgery for IE. The primary end point was early postoperative mortality. The main secondary end point was a composite end point for severe postoperative complications. RESULTS: During the study period, 264 patients were included. Early postoperative mortality was 14%. Prolonged CPBT [odds ratio (OR) 1.008, 95% confidence intervals (CIs) 1.003-1.01; P=0.009] and increasing age (OR 1.04, 95% CI 1.01-1.07; P = 0.02) independently predicted mortality, while an inverse association was observed for left ventricular ejection fraction (OR 0.93, 95% CI 0.89-0.97; P= 0.0007). The best mortality cut-offs were >72 min for XCT and >166 min for CPBT. Prolonged CPBT also predicted severe complications, along with age, stroke, preoperative mechanical ventilation and reduced left ventricular ejection fraction. When XCT was included in the multivariable models instead of CPBT, it was associated with both mortality and severe complications. CONCLUSIONS: Prolonged XCT and CPBT are associated with mortality and development of severe complications after valvular surgery for IE. Further validation of safe limits for XCT and CPBT might provide novel insights on how to improve intraoperative and postoperative outcomes of patients with IE.