Effects of preoperative β-blocker use on clinical outcomes after coronary artery bypass grafting: A report from the Japanese cardiovascular surgery database

Background: The authors evaluated the effect of preoperative β-blocker use on early outcomes in patients undergoing coronary artery bypass grafting (CABG) in Japan. Methods: The authors analyzed 34,980 cases of isolated CABGs, performed between 2008 and 2011, at the 333 sites recorded in the Japanese Cardiovascular Surgical Database. In addition to the use of multivariate models, a one-to-one matched analysis, based on estimated propensity scores for patients with or without preoperative β-blocker use, was performed. Results: The study population (mean age, 68 yr) comprised 20% women, and β-blockers were used in 10,496 patients (30%), who were more likely to have risk factors and comorbidities than patients in whom β-blockers were not used. In the β-blocker and non-β-blocker groups, the crude in-hospital mortality rate was 1.7 versus 2.5%, whereas the composite complication rate was 9.7 versus 11.6%, respectively. However, after adjustment, preoperative β-blocker use was not a predictor of in-hospital mortality (odds ratio, 1.00; 95% CI, 0.82 to 1.21) or complications (odds ratio, 0.99; 95% CI, 0.91 to 1.08). When the outcomes of the two propensity-matched patient groups were compared, differences were not seen in the 30-day operative mortality (1.6 vs. 1.5%, respectively; P = 0.49) or postoperative complication (9.8 vs. 9.7%; P = 1.00) rates. The main findings were broadly consistent in a subgroup analysis of low-risk and high-risk groups. Conclusion: In this nationwide registry, the use of preoperative β-blockers did not affect short-term mortality or morbidity in patients undergoing CABG.