Impact of Early and Delayed Stroke on In-Hospital and Long-Term Mortality After Isolated Coronary Artery Bypass Grafting

Stroke after coronary artery bypass grafting (CABG) is an infrequent, yet devastating complication with increased morbidity and mortality. We sought to determine risk factors for early (intraoperatively to 24 hours) and delayed (>24 hours to discharge) stroke and to identify their impact on long-term mortality after CABG. We studied 4,140 consecutive patients who underwent isolated CABG from 1992 to 2003. Long-term survival data (mean follow-up 7.4 years) were obtained from the National Death Index. Independent predictors for stroke and in-hospital mortality were determined by multivariate logistic regression analysis including all available preoperative, intraoperative, and postoperative risk factors. Independent predictors for long-term mortality were determined by multivariate Cox regression analysis. One hundred two patients (2.5%) developed early stroke and 36 patients (0.9%) delayed stroke. Independent predictors for early stroke were age, recent myocardial infarction, smoking, femoral vascular disease, body mass index, reoperation for bleeding, postoperative sepsis and/or endocarditis, and respiratory failure, whereas those for delayed stroke were female gender, white race, preoperative renal failure, respiratory failure, and postoperative renal failure. Early stroke was an independent predictor for in-hospital (odds ratio 3.49, 95% confidence interval [CI] 1.56 to 7.80, p = 0.002) and long-term (hazard ratio 1.70, 95% CI 1.30 to 2.21, p <0.001) mortalities. Delayed stroke was not an independent predictor for in-hospital (odds ratio 0.90, 95% CI 0.23 to 3.51, p = 0.878) or long-term (hazard ratio 0.66, 95% CI 0.38 to 1.17, p = 0.156) mortality. In conclusion, risk factors for early in-hospital stroke differ from those of delayed in-hospital stroke after CABG. Early stroke is an independent predictor for in-hospital and long-term mortalities, suggesting the need for a more frequent follow-up and appropriate pharmacologic therapy after discharge.