Research Activities #261, May 2002

blockers (drugs to slow the heart rate and reduce contractions of the heart muscle) prior to bypass surgery appear to have improved survival and fewer complications during and after the procedure, according to a study supported by the Agency for Healthcare Research and Quality (HS10403). Researchers indicate that up to 1,000 lives potentially could be saved each year by giving patients beta blockers. This is the first study to examine the outcomes of beta blocker use before bypass surgery. It was conducted by researchers at the Society of Thoracic Surgeons and the Duke Clinical Research Institute. Using an observational study approach, they accessed the Society of Thoracic Surgeons’ National Adult Cardiac Surgery Database to evaluate the use of beta blockers and health outcomes among 629,877 patients undergoing heart bypass surgery between 1996 and 1999 at 497 U.S. and Canadian hospitals. Patients who received beta blocker therapy before bypass surgery had lower rates of death in and out of the hospital within 30 days of surgery than those who did not have the therapy, 2.8 percent versus 3.4 percent, respectively. This modest survival benefit remained after adjusting for multiple preoperative risk factors such as diabetes and age. Also, use of beta blockers improved outcomes in patients for whom this therapy is considered risky. These include patients with heart failure, older age, underlying lung disease, and diabetes. In addition, use of beta blockers lessened the incidence of major complications, including stroke, renal failure, and extended duration of ventilation. These findings are consistent with those previously identified for beta blockers when used before noncardiac surgery or percutaneous coronary intervention (to restore normal blood flow to plaque-narrowed cardiac arteries). Although bypass surgery is one of the most commonly performed procedures in North America, only about 60 percent of patients were taking a beta blocker at the time of their surgery, according to the researchers. They believe that these Research Activities