Risk Factors Associated with Ischemic Stroke in the Immediate Postoperative Period of Cardiac Surgery

ABSTRACT Introduction: Stroke remains a major complication of cardiac surgery. Despite all efforts, the incidence of postoperative stroke remains as high as 6%. We aimed to investigate risk factors for ischemic stroke in a contemporary cohort of patients undergoing cardiac surgery. Methods: This is a retrospective cohort study of 678 consecutive adult patients who underwent cardiac surgery requiring cardiopulmonary bypass in a tertiary hospital in Brazil between July 1, 2011, and December 31, 2018. The primary outcome was the rate of early (perioperative and seven-day postoperative) stroke, defined as the occurrence of the outcome during the index admission. We developed a predictive model of stroke using the Poisson regression analysis with robust variance. Results: Postoperative stroke occurred in 24 patients (3.5%), 23 (3.3%) were ischemic, and 21 (3.0%) were diagnosed in the first 72 hours after surgical procedure. After multivariate analysis, the following factors were significantly associated with stroke: previous stroke/transient ischemic attack (relative risk [RR]=2.75; 95% confidence interval [CI], 1.11-6.82), carotid artery disease (RR=4.0; 95% CI, 1.43-11.0), previous atrial fibrillation (RR=3.26, 95% CI, 1.31-8.1), and postoperative platelets > 200,000/mm3 (RR=2.26; 95% CI, 1.01-5.1). Conclusion: We developed a contemporary model to determine risk predictors for stroke after cardiac surgery. This model may help clinicians to identify patients at risk and could be useful in clinical practice.