Escore de risco para acidente vascular cerebral em cirurgia cardíaca

Abstract

Introduction: Stroke is a complication responsible for high morbidity and mortality after cardiac surgery, affecting 1.3 to 4.3% and mortality between 13% and 41%. Several models have been proposed to assess the risk of mortality after cardiac surgery. However, most of these models doesn´t evaluate the postoperative morbidity. Objective: To develop a risk score model for postoperative stroke in patients undergoing cardiac surgery (coronary artery bypass surgery, valve replacement surgery and combined - CABG + valve replacement), with cardiopulmonary bypass (CPB). Methods: The study sample included data from 4,862 adult patients who underwent cardiac surgery between January 1996 to December 2012, at the Hospital São Lucas. Logistic regression was used to evaluate the relationship between risk factors and the development of stroke. After univariate and multivariate analysis, data from 3,258 patients were used to develop the model. Its performance has been validated in the remaining patients (n = 1,604). The final model was constructed with the total sample, remaining the same variables. The accuracy of the model was tested using the area under the ROC curve. Results: The estimated incidence for stroke in the postoperative period was 3% (149). Among patients who developed stroke, 59.1% were male, 51% were aged ≥ 66 years and 31.5% died. The mean age of the study population was 58.9 ± 12 years. In multivariate analysis, five variables remained independent predictors for the outcome: age, urgent / emergency surgery, peripheral arterial occlusive disease (PAOD), history of cerebrovascular disease (CVD) and cardiopulmonary bypass (CPB) time> 110 minutes. The area under the ROC curve obtained was 0.71 (95% CI 0.66 to .75). Conclusion: The risk score allows to establish the calculation of the incidence of stroke after cardiac surgery using clinical and surgical variables (age, surgical priority, PAD, CVD history and CPB time). From these variables, it was possible to construct a risk score that classifies patients as low, medium, high and very high operative risk for cerebrovascular stroke.