Predictors of stroke in patients undergoing coronary artery bypass grafting surgery: a prospective, nested, case-control study.

The objective of the present study was to assess the risk factors for stroke in patients undergoing coronary artery bypass grafting (CABG) surgery. We conducted a nested case-control study from a 9-year, prospective hospitalization cohort (n = 6245). Inclusion in the cohort included CABG between October 1993 and June 2002. Exclusion criteria included any other simultaneously performed surgery. Cases were defined as patients who underwent CABG and experienced a stroke (171 cases, 2.7% of the total), and controls were patients who underwent CABG without a stroke. Cases were matched to controls at a ratio of 1:3 (513 controls). The 39 predictor variables were pump time, body surface area, creatinine, previous percutaneous transcoronary angioplasty (PTCA), clamp time, coronary perfusion time, previous cardiac surgeries, hypertension, race, sex, previous myocardial infarction, family history of coronary disease, history of cerebrovascular disease, preoperative neurologic disease, pulmonary hypertension, aortic disease, previous intervention within 30 days, angina history, bleeding history, previous vascular surgery, diabetes, age, myocardial findings, chronic obstructive pulmonary disease, New York Heart Association class, previous gastrointestinal disease, current vascular disease, systemic diseases, vessels at last PTCA, PTCA result, current smoking, tobacco history, dialysis, current anticoagulant therapy, character of operation, left ventricular hypertrophy, hypercholesterolemia, and chronic corticosteroid therapy. There were 13 significant predictors of stroke. Regression analysis revealed 3 independent predictors of stroke: age >70 years (odds ratio [OR], 4.61; 95% confidence interval [CI], 2.84-6.07), poor preoperative neurologic status (OR, 4.24; 95% CI, 2.02-5.79), and previous cardiac surgery (OR, 1.75; 95% CI, 1.05-2.91). We conclude that in patients undergoing CABG surgery, the independent predictors for stroke, in order of risk, are age >70 years, poor preoperative neurologic status, and previous cardiac surgery.