COPD is an independent risk factor for cardiovascular death in patients with atrial fibrillation, but not an independent risk factor for stroke

by Bruce Sylvester: Researchers reported on May 20, at American Thoracic Society/ATS 2015 annual meeting in Denver that the presence of chronic obstructive pulmonary disease, COPD, is an independent  risk factor  for death from a cardiovascular disease in patients with atrial fibrillation, but it is not independently associated with increase in the risk of stroke or systemic embolism.

“Other studies have shown that COPD is an independent risk factor for cardiovascular disease, but what hadn’t been studied was whether COPD was an independent risk factor for stroke, specifically among patients with atrial fibrillation,” said Michael Durheim, MD, a pulmonary and critical care fellow at Duke University Medical Center in Durham, North Carolina.

Researchers from Duke and the Mayo Clinic analyzed retrospectively data from 18,206 subjects in ARISTOTLE (Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation), a trial comparing two anticoagulants, apixaban and warfarin, for reducing the risk of stroke or systemic embolism in atrial fibrillation patients.

The endpoint of this new analysis was the correlation  between the presence of COPD and stroke events in the patient population.

The researchers reported that COPD was present in 1,950 (10.8%) of the 18,134 subjects for whom pulmonary disease history was available.

After adjusting for age, smoking and other independent risk factors, COPD was not associated with an increased risk of stroke or systemic embolism (adjusted HR 0.86 [95% CI 0.61, 1.21], p = 0.382). But COPD was associated with increased risk for death from all causes by 54 percent (adjusted HR 1.54 [95% CI 1.31, 1.82], p < 0.001), including cardiovascular and non-cardiovascular death.

Durheim said that since COPD independently raises mortality in patients with atrial fibrillation, more studies are needed to “elucidate the mechanisms” by which COPD contributes to an increase in the risk of death.

He added that the effect of apixaban compared with warfarin on stroke or systemic embolism did not differ between subjects with and without COPD (HR 0.92 vs 0.78, interaction p = 0.617). “The presence of COPD doesn’t need to affect provider’s choice of an anticoagulant,” he said.