Canadian scientists are urging physicians to closely monitor older patients taking bronchodilator and anticholinergic drugs to treat COPD because they have a greater risk of heart attacks.
Their analysis, published today in JAMA Internal Medicine, found a 28 percent greater risk of acute myocardial infarction (heart attack), heart failure, stroke, and cardiac arrhythmia among patients ages 66 and older who received new prescriptions for long-acting bronchodilators.
Andrea Gershon, M.D., M.S., of the Institute for Clinical Evaluative Sciences in Ontario, led the study, which focused on long-acting inhaled beta-agonists (LABAs) and long-acting inhaled anticholinergics (LAAs), currently used as first-line treatments for COPD.
Her study population included 191,000 seniors in Ontario who sought treatment for COPD between September 2003 (when LAAs were first commonly prescribed) and March 2009. Patients not using LABAs or LAAs formed the control group for the study.
Canadians have universal public health insurance, and complete medical records were available to the researchers. The study authors found no significant difference in heart attack risk between patients using LABAs and those using LAAs.
What Are Bronchodilators?
Long-acting beta-agonists and anticholinergics relax and open a patient's airways, making it easier to breathe. These drugs are considered the gold standard for treating COPD.
LABAs target smaller airways, while LAAs target the central airways. For this reason, they are often used in combination to provide more comprehensive relief of COPD symptoms.
According to an in-depth report on COPD treatments from the University of Maryland Medical Center, previous studies have shown that both of these drugs increase cardiovascular risk. However, these studies are considered by some in the medical community to be inconclusive.
One study showed that using an inhaled anticholinergic medication for more than one month was linked to a nearly 60 percent greater risk of heart attack, stroke, or death. Another study found that the short-acting anticholinergic ipratropium increased the risk of death from cardiovascular causes by 30 percent, particularly in recently diagnosed men.
At the same time, large, randomized clinical trials performed by drug developers suggest there is no increased risk of a cardiovascular event with either of these drug types.
To be on the safe side, Gershon and her colleagues urge caution. “Close monitoring of COPD patients requiring long-acting bronchodilators is needed regardless of drug class,” the study concludes.
What Causes COPD?
COPD is a progressive lung disease caused by long-term exposure to cigarette smoke, air pollution, chemical fumes, dust, and other toxic gases. It is the third leading cause of death in the U.S., according to the American Lung Association.
Over time, COPD damages the lungs and causes a loss of elasticity in the airways and air sacs, which makes it much harder for patients to breathe. People with COPD have both emphysema and chronic bronchitis.
COPD is considered a preventable disease most often caused by smoking. An estimated 90 percent of deaths from COPD are linked to smoking, according to the Centers for Disease Control and Prevention.
Other drugs used to treat COPD symptoms include expectorants and mycolytics to loosen mucus in the airways, antibiotics to treat acute bronchial infections and pneumonia, and quinolones to clear certain types of bacteria from the lungs.
For now, only bronchodilator drugs—however flawed—are able to improve lung function and quality of life for those living with COPD.