Long-acting beta-agonists and anticholinergics pose similar cardiovascular risks

Patients with chronic obstructive pulmonary disease (COPD) faced increased risk of a cardiovascular event after starting treatment with a long-acting bronchodilator, whether it was a beta-agonist or an anticholinergic, a new study found.

Researchers conducted a nested case-control analysis of a retrospective cohort study, using a database of adults 66 years or older in Ontario, Canada, treated for COPD between September 2003 and March 2009. They compared the rate of emergency department (ED) visits and hospitalizations for cardiovascular events among patients newly prescribed a drug in either class and those not taking either type of drug.

Results were published by JAMA Internal Medicine on May 20.

Of the almost 200,000 patients, 28% had a hospitalization or ED visit for a cardiovascular event. Patients in the newly prescribed group were significantly more likely to have an event than non-users (adjusted odds ratio, 1.31 for beta-agonists vs. non-use [95% confidence interval [CI], 1.12 to 1.52; P<0.001) and 1.14 for anticholinergics vs. non-use (95% CI, 1.01 to 1.28; P=0.03]). Between the two medications, there was no significant difference in events.

The results confirm previous observational studies finding cardiovascular risks of these drugs, although they contradict some data from randomized controlled trials, perhaps due to differences between patient populations in controlled trials and the real world, the study authors speculated. As with any observational study, there is a risk of confounding, but it appears that new users of these drug classes have similarly increased risk of cardiovascular events.

“These results support the need for close monitoring of all patients with COPD who require long-acting bronchodilators regardless of drug class,” the authors concluded.

The findings are helpful, but still leave a lot of unanswered questions, including what kind of monitoring is appropriate for these patients, wrote the author of an accompanying commentary. Physicians are also still uncertain, and await future research findings, on the relative safety of different delivery methods of anticholinergics and the use of a beta-agonist alone or with an inhaled corticosteroid, the commentary noted.