Study evaluates differences between men and women with atrial fibrillation

Among patients with atrial fibrillation, women have more symptoms, more functional impairment and worse quality of life compared with men, according to an observational cohort study.

Women also had a higher risk of stroke or systemic embolism, higher risk-adjusted survival and lower risk-adjusted cardiovascular death compared with men.

Lead researcher Jonathan P. Piccini, MD, MHS, of the Duke Clinical Research Institute in Durham, North Carolina, and colleagues published their results in JAMA Cardiology on May 18.

The researchers analyzed the ORBIT-AF (Outcomes Registry for Better Informed Treatment of Atrial Fibrillation) study, a prospective registry of 10,135 patients with incident and prevalent atrial fibrillation who enrolled at 176 sites between June 2010 and August 2011.

At baseline, the mean age was approximately 75 years old, and 42 percent of patients were women. The women were older, had lower frequencies of obstructive sleep apnea and coronary artery disease, and had higher frequencies of left ventricular ejection fraction of 50 percent or greater. Women also had worse renal function, worse overall Atrial Fibrillation Effects on Quality of Life scores and higher median CHA2 DS2 -VASc scores.

When accounting for baseline risk, women had a lower adjusted risk for all-cause mortality, cardiovascular death and noncardiovascular death after a median follow-up period of 2.3 years.

After risk adjustment, the incidence of new-onset heart failure, MI, revascularization, major bleeding, all-cause hospitalization and sudden cardiac death were similar between men and women. In addition, women had a higher risk for stroke or non-central nervous system embolism.

The researchers cited a few limitations of the study, including that sites and patients volunteered to participate in the registry. In addition, the median age was older than patients from other atrial fibrillation registries. They also said there may have been residual or unmeasured confounding.

“Despite a higher risk for stroke, women had improved risk-adjusted all-cause survival and lower risk-adjusted cardiovascular death compared with men,” the researchers wrote. “The reasons for this stroke-survival paradox may have important implications for [atrial fibrillation]-directed therapies in women and men.”