Preoperative beta-blocker use and mortality and morbidity following CABG surgery in North America.
BACKGROUND
beta-Blockade therapy has recently been shown to convey a survival benefit in preoperative noncardiac vascular surgical settings. The effect of preoperative beta-blocker therapy on coronary artery bypass graft surgery (CABG) outcomes has not been assessed.


OBJECTIVE
To examine patterns of use of preoperative beta-blockers in patients undergoing isolated CABG and to determine whether use of beta-blockers is associated with lower operative mortality and morbidity.


METHODS
Observational study using the Society of Thoracic Surgeons National Adult Cardiac Surgery Database (NCD) to assess beta-blocker use and outcomes among 629 877 patients undergoing isolated CABG between 1996 and 1999 at 497 US and Canadian sites.


METHODS
Influence of beta-blockers on operative mortality, examined using both direct risk adjustment and a matched-pairs analysis based on propensity for preoperative beta-blocker therapy.


RESULTS
From 1996 to 1999, overall use of preoperative beta-blockers increased from 50% to 60% in the NCD (P<.001 for time trend). Major predictors of use included recent myocardial infarction; hypertension; worse angina; younger age; better left ventricular systolic function; and absence of congestive heart failure, chronic lung disease, and diabetes. Patients who received beta-blockers had lower mortality than those who did not (unadjusted 30-day mortality, 2.8% vs 3.4%; odds ratio [OR], 0.80; 95% confidence interval [CI], 0.78-0.82). Preoperative beta-blocker use remained associated with slightly lower mortality after adjusting for patient risk and center effects using both risk adjustment (OR, 0.94; 95% CI, 0.91-0.97) and treatment propensity matching (OR, 0.97; 95% CI, 0.93-1.00). Procedural complications also tended to be lower among treated patients. This treatment advantage was seen among the majority of patient subgroups, including women; elderly persons; and those with chronic lung disease, diabetes, or moderately depressed ventricular function. Among patients with a left ventricular ejection fraction of less than 30%, however, preoperative beta-blocker therapy was associated with a trend toward a higher mortality rate (OR, 1.13; 95% CI, 0.96-1.33; P =.23).


CONCLUSIONS
In this large North American observational analysis, preoperative beta-blocker therapy was associated with a small but consistent survival benefit for patients undergoing CABG, except among patients with a left ventricular ejection fraction of less than 30%. This analysis further suggests that preoperative beta-blocker therapy may be a useful process measure for CABG quality improvement assessment.
Ferguson
T Bruce
TB
Department of Surgery, Louisiana State University Health Sciences Center, New Orleans, LA 70012-2822, USA. tbruceferg732@pol.net
Coombs
Laura P
LP
Peterson
Eric D
ED
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000368:Aged; D001026:Coronary Artery Bypass / Q000401:mortality*; D004363:Drug Utilization / Q000706:statistics & numerical data / Q000639:trends; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009017:Morbidity; D009656:North America; D017063:Outcome Assessment, Health Care; D011183:Postoperative Complications / Q000453:epidemiology; D011300:Preoperative Care; D016019:Survival Analysis
D000319:Adrenergic beta-Antagonists