Repeat valvular operations: bench optimization of conventional surgery.

BACKGROUND: Repeat heart valve operations have become a quite common procedure. We reviewed our experience with reoperative valvular surgery during a 6-year period to assess the risk factors affecting in-hospital mortality and medium-term survival.
METHODS: A series of 316 redo procedures performed on a total of 290 patients in the period between 1997 and 2002 at our institution was retrospectively analyzed. Univariate and multivariable analyses were performed.
RESULTS: In-hospital mortality was 3.8%; overall mortality at the end of a 30-month follow-up was 9.3%. We identified advanced New York Heart Association class, advanced age, depressed ejection fraction, emergent or urgent presentation, impairment of renal function, and involvement of tricuspid valve as predictors of mortality. In contrast, duration of cardiopulmonary bypass and multiple valve procedure were not associated with increased short-term risk.
CONCLUSIONS: The present study is characterized by particular attention in reducing confounding variables and biases correlated to heterogeneities. The main determinants of mortality are related to the degree of patients' illness rather than to inherent technical factors of reoperations. Although highest-risk individuals (previous coronary artery bypass grafting or coexistence of aortic aneurysm) were excluded from the study, our data suggest that patients undergoing isolated redo valvular procedures now face operative risks that are comparable to primary intervention.