Preoperative beta-blocker therapy in coronary artery bypass surgery: a propensity score analysis of outcomes

Preoperative beta-blockade in patients undergoing coronary artery bypass grafting (CABG) has recently been shown to be beneficial in improving the early outcomes after surgery. We aimed to quantify the effect of preoperative beta-blockade on outcomes in our own patient population. We performed a retrospective analysis on CABG patients identified from our prospectively collected cardiac surgery database. Logistic regression was used to adjust in-hospital outcomes for differences in patient and disease characteristics. Treatment selection bias was controlled by deriving a propensity score for beta-blocker therapy. Consecutive patients (4381) underwent CABG on cardiopulmonary bypass between 1 April 1997 and 31 March 2002, with 2836 (64.7%) on preoperative beta-blocker therapy. After adjustment with the propensity score, beta-blocker therapy was significantly associated with a reduction in post-operative stroke (adjusted OR 0.59, p=0.011). The incidence of atrial arrhythmia was significantly increased in patients who had received preoperative beta-blockers (adjusted OR 1.21, p=0.011). There were no significant differences in operative mortality or other morbidity outcomes. Preoperative beta-blocker therapy significantly reduces the incidence of post-operative cerebrovascular events in patients undergoing on-pump coronary artery bypass surgery.