SNOWMASS, COLO. – Overlooking the common modifiable risk factors in patients with atrial fibrillation is missing out on an excellent opportunity to help curb the growing global pandemic of the arrhythmia, Patrick T. O’Gara, MD, said at the Annual Cardiovascular Conference at Snowmass.
“My purpose here is a wake up call to improve screening for and treatment of modifiable risk factors in patients with atrial fibrillation,” declared Dr. O’Gara, professor of medicine at Harvard Medical School, Boston.
Dr. Patrick T. O'Gara
Overweight/obesity: Investigators at the University of Adelaide (Australia) demonstrated in the LEGACY trial that patients with atrial fibrillation (AF) and a BMI of 27 kg/m2 or more reduced their AF symptom burden in a dose-response fashion as they shed excess pounds as part of an intensive weight management program. Those who shed at least 10% of their baseline body weight had a 46% rate of 5-year freedom from AF without resort to rhythm control medications or ablation procedures of 46%. With 3%-9% weight loss, the rate was 22%. And with 3% weight loss, it was 13%.
The best results came from sustained linear weight loss. Weight fluctuations of greater than 5% – the classic yoyo dieting pattern – partially offset the overall benefit of weight loss with respect to recurrent AF (J Am Coll Cardiol. 2015 May 26;65(20):2159-69).
In a separate study, the same team of Australian investigators offered an opportunity to participate in a risk factor management program to patients with AF and a BMI of 27 kg/m2 or more who were undergoing radiofrequency ablation for their arrhythmia. Participants had significantly fewer repeat ablation procedures during followup and were also less likely to be on antiarrhythmic drugs than the patients who opted for usual care (J Am Coll Cardiol. 2014 Dec 2;64(21):2222-31).
Alcohol: The ‘holiday heart’ syndrome is well known, but alcohol consumption beyond binging can increase risk for AF. Dr. O’Gara noted that in a recent review article entitled “Alcohol and Atrial Fibrillation: A Sobering Review,” investigators at the University of Melbourne showed that while the relationship between the number of standard drinks per week and risk of cardiovascular mortality is J-shaped, with a nadir at 14-21 drinks per week in men and fewer in women, the risk of developing AF is linear over time and appears to increase incrementally with every additional drink per week (J Am Coll Cardiol. 2016 Dec 13;68(23):2567-76).
Also, a prospective study of nearly 80,000 Swedes free from AF at baseline, coupled with a meta-analysis of seven prospective studies found that for each additional drink per day consumed the risk of developing AF rose over time by roughly a further 10% compared to that of teetotalers (J Am Coll Cardiol. 2014; Jul 22;64(3):281-9).
Physical inactivity: In the prospective Tromso Study, in which more than 20,000 Norwegian adults were followed for 20 years, leisure time physical activity displayed a J-shaped relationship with the risk of developing AF. Moderately active subjects were an adjusted 19% less likely to develop AF than those with low physical activity, while the risk in subjects who regularly engaged in vigorous physical activity was 37% higher than in the low-activity group (Eur Heart J. 2016 Aug 1;37(29):2307-13).
“This effect of moderate exercise might be due to the associated weight loss, improved endothelial function, better sleep, perhaps a better balance between the sympathetic and parasympathetic nervous systems,” Dr. O’Gara observed.
How much physical activity is right for patients with AF? Dr. O’Gara said one of the best reviews he’s seen came from the University of Adelaide group (Circulation. 2016 Feb 2;133(5):457-9). They recommended a total of 120-200 minutes of exercise per week spread over three to five sessions. While the research base is strongest for moderate-intensity exercise, the Australians also noted the effectiveness and safety of a novel program of repeated 4-minute intervals of high-intensity exercise at 85%-95% of peak heart rate as demonstrated in a randomized controlled trial by investigators at the Norwegian University of Science and Technology in Trondheim. They showed this approach resulted in reduced time in AF and decreased AF symptoms coupled with improved quality of life and left atrial and ventricular function (Circulation. 2016 Feb 2;133(5):466-73).
“I think you could look at this review and feel very confident that there is some evidence base to substantiate your strong recommendation that patients actively engage in exercise as treatment for their atrial fibrillation,” the cardiologist said.
Sleep apnea: Investigators at Brigham and Women’s Hospital in Boston have demonstrated that effective treatment of sleep apnea with continuous positive airway pressure in patients with atrial fibrillation is associated with smaller atrial size and ventricular mass, lower blood pressure, and a significantly reduced risk of recurrent AF following an AF ablation procedure (J Am Heart Assoc. 2013 Nov 25;2(6):e000421).
“Sleep hygiene is one of the least attended aspects of cardiovascular health,” according to Dr. O’Gara. “We need to ask the partner or spouse, ‘How well does your partner sleep? Do you hear thrashing about, snoring, gagging, or notice restless legs?’ Heart failure folks are really tuned into this, but in the practice of seeing patients come into the emergency room with new-onset atrial fibrillation, it’s tenth on the list of five questions one would ask.”
Dr. O’Gara reported having no financial conflicts.