Desarrollo y Validación Externa de un Puntaje Predictivo de Mediastinitis Postoperatoria en Cirugía Cardíaca derivado del Registro Multicéntrico CONAREC XXVI

Objective: The aim of this analysis was to define independent predictive variables for the development of mediastinitis after cardiovascular surgery and develop a validated score to stratify the risk for mediastinitis.Methods: Data were retrieved from the CONAREC XVI study comprising adults undergoing cardiovascular surgery between September 2007 and October 2008 in 49 centers of 16 provinces in Argentina. Mediastinitis was defined as the presence of clinical signs attributable to the condition or positive cultures. Epidemiological and clinical variables, type of surgery, intraoperativeand postoperative variables and complementary tests were evaluated. A logistic regression model was used toidentify the independent variables associated with perioperative mediastinitis. A two-tailed alpha error < 0.05 was consideredstatistically significant. A score was constructed and was externally validated in patients from other surgical centers.Results: A total of 2553 patients were analyzed: coronary artery bypass graft surgery, 1465 patients (57.4%); aortic valve replacement,359 (14.1%); mitral valve surgery, 169 (6.6%); combined procedure (revascularization-valve surgery), 312 (12.2%); other procedures, 248 (9.7%). The overall incidence of medistinitis was 1.88%. The variables associated with the development of mediastinitis were: smoking habits (OR, 2.3; 95% CI,1.1-5,1; p=0.02), severe left ventricular dysfunction (OR, 2.8; 95% CI,1.3-6.2; p=0.001), reoperation (OR, 4,6; 95% CI,1.8-11.3; p=0.01) and postoperative renal failure (OR, 4.3; 95% CI, 1.9-9,6;p=0.0001). A risk score was constructed assigning 1 point for severe left ventricular dysfunction, 1 point for the history of smoking habits, 2 points for the development of renal failure and 2 points for need for reoperation. The area under the ROC curve for mortality was 0.72 (95% CI, 0.64-0,81; Hosmer Lemeshow test p=0.9). The external validation was performed on1657 patients, mean age 62.8±13.3 years. The incidence of mediastinitis was 1.6%. The area under the ROC curve for the development of mediastinitis was 0.70 (95% CI, 0.58-0.80; p=0.001).Conclusions: The construction of a predictive score for the development of postoperative mediastinitis after cardiovascular surgery is relevant for daily practice for the prevention and early detection of this severe complication.