Risk factors for cerebrovascular accident after isolated coronary artery bypass grafting in Veterans.

Background: Cerebrovascular accident (CVA) after coronary artery bypass grafting (CABG) is a devastating complication. Patient comorbidities and intraoperative elements contribute to the risk of CVA. The aim of this study is to identify risk factors for CVA in Veterans undergoing CABG.

Methods: Veterans undergoing isolated CABG from 2008 to 2019 were retrospectively identified using the Veterans Affairs Surgical Quality Improvement Program (VASQIP) database. Thirty-day postoperative outcomes were observed. Univariate analysis followed by multivariable logistic regression identified independent risk factors for postoperative CVA. Receiver operating characteristic diagnostics identified optimal inflection points between continuous risk factors and odds of CVA.

Results: Twenty-eight thousand seven hundred fifty-seven patients met inclusion criteria. Incidence of CVA was 1.1% (310 cases). In multivariate analysis, preoperative cerebrovascular disease had the strongest association with postoperative CVA (adjusted odds ratio = 2.29; p < .001). There was an inverse relationship between CVA incidence and ejection fraction (EF), with EF of 35%-39% conferring a 2.11 times higher risk compared to EF >55% (p < .001). CVA incidence was not different in on-pump versus off-pump cases; however, after 104 min or more on bypass patients had a 55% greater adjusted odds of CVA (p < .001). Other risk factors included poor kidney function, prior myocardial infarction, and intra-aortic balloon pump use.

Conclusion: The risk of CVA after CABG is multifactorial and involves multiple organ systems, including cardiac disease, poor renal function, and cerebrovascular disease, which was the strongest contributing risk factor. Optimization of these comorbidities and time on bypass may help improve clinical outcomes and lower the risk of this devastating complication.