With atrial fibrillation rates rising as the population ages, more than 12.1 million Americans are expected to have the condition by 2030. Recent research from the Smidt Heart Institute at Cedars-Sinai is challenging the conventional wisdom about AFib and could lead to major improvements in how it is managed, diagnosed and treated.

Heightened Risk Factor

Women have long been thought to face a lower risk of AFib than men. But a Cedars-Sinai study published in JAMA Cardiology revealed that women are actually 50% more likely to develop the arrhythmia when the height differences between genders was factored in.

The findings arose from a prospective cohort analysis within the randomized VITAL Rhythm Study. VITAL examined the effects of vitamin D and omega-3 fatty acid supplements on older adults who were diagnosed with AFib after no prior history of heart disease.

“This is the first study to show an actual flip in the risk of atrial fibrillation,” notes the study’s senior author Christine Albert, MD, MPH, who is the VITAL trial leader and chair of the Department of Cardiology in the Smidt Heart Institute.

The taller people are, the greater their risk for AFib. And since women tend to be shorter than men, previous studies have shown them to have a lower risk of developing the condition.

“Our study, however, suggests that if a man and a woman are the same height, the woman would be more likely to develop AFib,” says Albert, the Lee and Harold Kapelovitz Distinguished Chair in Cardiology at Cedars-Sinai. “So, instead of asking why women are protected from AFib, we now must seek to understand why women are at higher risk.”

As the general population increases in size—both in height and weight—cardiologists can expect greater numbers of AFib cases. “It’s now more imperative than ever to be offering preventive strategies and early diagnostic interventions to all patients—regardless of sex or gender,” Albert says.

Fish Oil Fallacy

Another VITAL finding showed that, while fish oil offers certain health benefits, taking omega-3 fatty acid supplements has no effect on preventing AFib. Instead, a number of studies suggest that high doses of omega-3 could actually increase one’s risk for AFib.

To get to the heart of the issue, Albert and colleagues conducted a meta-analysis of findings from seven different trials. They found that patients taking more than 1 gram of omega-3 supplements daily had a 49% increased risk of AFib, compared to just 12% increased risk for patients who took 1 gram or less each day.

Based on these results, Albert recommends that clinicians discuss the potential risk of AFib with patients before suggesting high-dose omega-3 supplements to keep potentially harmful triglycerides in check. She also advises them to inform patients of the signs and symptoms of AFib so an early diagnosis can be made and coupled with appropriate treatment. In addition, risk-to-benefit ratios in studies examining the effects of omega-3 fatty acid supplements should be better defined.

As Cedars-Sinai continues redefining AFib prevention and management strategies, Albert says, these studies constitute important steps “for the medical community to take note of” in “discussing AFib risk with all patients, whether male or female.”

For more information about Cedars-Sinai’s AFib program and research, please call 424-314-2406.