Study Links Atypical Afib to Worse Outcomes

According to new research, atypical and asymptomatic presentations of atrial fibrillation (Afib) are connected to a much greater risk of poor outcomes; a finding that remained statistically significant after adjusting for comorbidities and warfarin use.

A team led by researchers from the Mayo Clinic studied 1,000 randomly selected incident cases of Afib in Minnesota’s Olmstead County—located near the Mayo Clinic—between the years 2000 and 2010. Among the 476 uncomplicated cases of Afib, 40% were typical presentations with palpilations, while 26% demonstrated atypical symptoms such as dyspnea, fatigue or lightheadedness. In addition, 34% were asymptomatic. Over the course of the 6-year follow-up period, 59 cerebrovascular events and 149 deaths occurred among this population, according to the authors.
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Overall, the investigators found that multiple risks were higher for those with asymptomatic Afib upon presentation. In comparison to typical symptomatic Afib patients, patients presenting with asymptomatic Afib showed a 2.70-fold elevated risk of cerebrovascular events, a 3.12-fold higher risk of cardiovascular mortality, and a 2.96-fold greater risk of all-cause mortality. While previous studies have revealed no effect or reduced risk in asymptomatic Afib patients, the inclusion of secondary Afib may have confounded the findings in this case, the authors noted, adding that the study could not establish a cause for the difference in prognosis among the various patient groups.

“Most patients with atrial fibrillation present with symptoms other than palpitations, and often with no symptoms at all,” says Peter Noseworthy, MD, a physician in the department of cardiovascular diseases at the Mayo Clinic, and a co-author of the study.        

However, he says, “it’s important for clinicians to keep in mind that these patients are at risk for adverse events and need aggressive risk-factor control.”

—Mark McGraw

Reference:

Konstantinos S, Gersh B, et al. Typical, Atypical, and Asymptomatic Presentations of New-Onset Atrial Fibrillation in the Community: Characteristics and Prognostic Implications. Heart Rhythm. 2016. [epub ahead of print]. DOI: http://dx.doi.org/10.1016/j.hrthm.2016.03.003