Preoperative beta-blocker use should not be a quality metric for coronary artery bypass grafting

Background Preoperative beta-blockade for coronary artery bypass grafting (CABG) has become an accepted hospital quality metric. However, single-institution reports regarding the benefits of beta-blocker (ß-blocker) use are conflicting. The purpose of this study was to evaluate the associations between preoperative beta-blocker use and outcomes within a large, regional cohort. Methods Patient records from a statewide, multi-institutional Society of Thoracic Surgeons (STS) certified database for isolated CABG operations (2001 to 2011) were extracted and stratified by preoperative ß-blocker use. The influence of preoperative ß-blockers on risk-adjusted outcomes was assessed by hierarchical regression modeling with adjustment for preoperative risk using calculated STS predictive risk indices. Results A total of 43,747 (age, 63 years; ß-blocker 80% versus non ß-blocker 20%) patients were included. Median STS predicted risk of mortality scores for ß-blocker patients were incrementally lower (1.2% vs 1.4%, p < 0.001). Non ß-blocker patients more frequently developed pneumonia (3.5% vs 2.8%, p = 0.001), while ß-blocker patients surprisingly had greater intraoperative blood usage (16% vs 11%, p < 0.001). There was no difference in unadjusted mortality (ß-blocker: 1.9% vs non ß-blocker: 2.2%, p = 0.15). After risk adjustment, preoperative ß-blocker use was not associated with mortality (p = 0.63), morbidity, length of stay (p = 0.79), or hospital readmission (p = 0.97). Conclusions Preoperative ß-blocker use is not associated with risk-adjusted mortality, several measures of morbidity, or hospital resource utilization after CABG operations. Thus, these data suggest that the routine use of preoperative ß-blockers for CABG operations should not be used as a measure of surgical quality.