Validation of MagedanzSCORE as a predictor of mediastinitis after coronary artery bypass graft surgery

Abstract

Objective: The aim of this study is to evaluate the applicability of a new score for predicting mediastinitis - MagedanzSCORE - in patients undergoing coronary artery bypass graft (CABG) surgery in the Division of Cardiovascular Surgery of Pronto Socorro Cardiológico de Pernambuco - PROCAPE.

Methods: Retrospective study involving 500 patients operated between May/2007 and April/2010. The registers contained all the information used to calculate the MagedanzSCORE. The outcome of interest was mediastinitis. We calculated sensitivity, specificity, positive predictive value, negative predictive value, concordance and accuracy. The accuracy of the model was evaluated by ROC (receiver operating characteristic) curve.

Results: The incidence of mediastinitis was 5.6%, with a lethality rate of 32.1%. In univariate analysis, the five variables of the MagedanzSCORE were predictors of postoperative mediastinitis: chronic obstructive pulmonary disease (OR 6.42; 95.0% CI 2.76-14.96; P<0.001), obesity (OR 3.06; 95.0% CI 1.32-7.09; P=0.009), surgical reintervention (OR 82.40; 95.0% CI 30.40-223.30; P<0.001), multiple transfusion (OR 3.33; 95.0% CI 1.52-7.29; P=0.003) and stable angina class IV or unstable (OR 2.59; 95.0% CI 1.19-7.64; P=0.016) according to Canadian Cardiovascular Society. The score had a sensitivity of 96.4%, specificity of 90.0%, positive predictive value of 36.5%, negative predictive value of 99.8% and 90.4% concordance. The accuracy measured by the area under the ROC curve was 96.2% (95.0% CI 94.5%-97.9%).

Conclusions: The MagedanzSCORE proved to be a simple and objective index, revealing a satisfactory predictor of development of postoperative mediastinitis in patients undergoing CABG surgery at our institution.