The medicines under scrutiny are called inhaled anticholinergics, which work by relaxing the muscles around constricted airways and relieving symptoms such as shortness of breath.
The use of two commonly prescribed anticholinergics, Spiriva and Atrovent, for more than a month boosted the risk of heart attack, stroke, or dying of cardiovascular problems by 58%, says Sonal Singh, MD, MPH, assistant professor of internal medicine at Wake Forest University School of Medicine in Winston-Salem, N.C., and lead author of the study, which appears in The Journal of the American Medical Association.
Singh and colleagues pooled the results of 17 randomized trials that included nearly 15,000 patients who took the anticholinergics or a control treatment. "Every study points in the same direction," he tells WebMD.
Meanwhile, pharmaceutical industry spokespeople issued a statement strongly disagreeing with the conclusions of the study, issuing their own new analysis that they say confirms the safety of Spiriva.
They found that the COPD medicines increased risk of death from cardiovascular disease as well as the risk of stroke or heart attack when the three outcomes were grouped together, but the drugs did not significantly increase the risk of death from all causes.
While 1.2% of control patients had a heart attack, stroke, or died from cardiovascular disease during the follow-up (which ranged from six weeks to five years), 1.8% of those on the anticholinergics did. That accounts for the 58% increase.
When Singh looked at the individual outcomes, rather than as a group, the increased risk for stroke didn't turn out to be significant, but the risk for heart attack and death from cardiovascular disease remained so.
The latest research isn't the first to uncover the risk. Atrovent was linked with a 34% increased risk of cardiovascular death by other researchers, who published their findings in the Annals of Internal Medicine last week.