Researchers found that beta-blockers significantly reduce mortality in patients with chronic obstructive pulmonary disease (COPD) undergoing non-cardiac surgery, according to a study in the October issue of the American Journal of Respiratory and Critical Care Medicine.
“Patients with COPD frequently have unrecognized, atherosclerotic disease. This is also a major cause for late morbidity and mortality,” said principal investigator Don Poldermans, MD, PhD, of the Erasmus Medical Center in Rotterdam, the Netherlands.
The researchers wrote that clinical trials on the benefits of using preoperative beta-blockers to lower the risk of cardiovascular (CV) events in patients undergoing non-cardiac surgery have yielded inconsistent results. Recent guidelines from the American Heart Association (AHA), however, recommend beta-blockers before non-cardiac surgery for patients who are at high risk for or who have known CV disease.
Yet, patients with COPD, who have an increased risk of cardiovascular disease, often do not receive preoperative beta-blockers because of potential side-effects such as aggravated bronchospasm or airway obstruction, according to the authors. Moreover, the benefits of beta-blockers have not been examined in a population of patients with COPD undergoing non-cardiac disease.
Investigator evaluated the mortality outcomes of more than 3,000 consecutive patients who underwent vascular surgery at Erasmus between 1990 and 2006. They looked at the effect of a low dose of beta-blockers (less than 25 percent maximum recommended therapeutic dose), compared to an intensified dosage (more than 25 percent maximum recommended therapeutic dose).
Of the 3,371 patients evaluated, 31 percent received cardio-selective beta-blockers at their initial hospitalization. The researchers found that cardio-selective beta-blockers were independently associated with reduced 30-day mortality in both patients with and without COPD. In the 30 days after surgery, the COPD patients who did not receive beta-blockers were twice as likely to die as those who did (8 vs. 4 percent).
During the follow-up period, 40 percent of COPD patients on beta-blockers died, whereas 67 percent who were not on beta-blockers died. The finding was not statistically significant. Researchers noted the beta-blockers were well tolerated, without inducing respiratory adverse events.
They also found that in COPD patients, an intensified, but not a low dose, of beta-blockers was associated with reduced 30-day mortality, but in the long term, both intensified and low dosages were associated with similar reductions in mortality. In patients without COPD, both low and intensified doses were associated with reduced mortality in 30-days but in the long term, only the intensified dose was associated with a nonsignificant trend in reduced mortality.
The findings demonstrate that carefully selected patients with COPD can tolerate cardioselective beta-blockers without experiencing respiratory complications. They also show that COPD patients may be protected by beta-blocker therapy from CV complications of surgery, such as MI, the researchers concluded.