The prevalence of atrial fibrillation (AF) is estimated to reach 12.1 million by 2030, fueled primarily by the steady aging of the population. As prevalence rises, clinicians are becoming increasingly facile with the three “pillars” of AF management—prevention of thromboembolism, rhythm control, and rate control. However, the guidelines and data for prevention of AF, which may actually be more critical to management of this epidemic, continue to be limited.
A recent "Review Topic of the Week,” in the December 29 issue of Journal of the American College of Cardiology, presented an excellent summary of the data and recommendations for modification of seven atherosclerotic cardiovascular disease risk factors, which are also risk factors for AF. The main conclusions are summarized below.
1) Obesity. The first recommendation they offer is for weight loss, given the association of AF with increased BMI. A recent meta-analysis found that for every 5 kg/m2 increase in BMI, there was a 10-29% higher relative risk for new-onset or post-operative AF. BMI is now part of prediction models for new-onset AF.
2) Exercise. The next recommendation is for light- to moderate-intensity exercise (since long-duration endurance training and extreme athleticism have been associated with increased risk of AF). In the Cardiovascular Health Study, among those who walked for exercise, walking greater distances or at a faster pace was associated with a greater reduction in incident AF. In the Women’s Health Initiative study, increased physical activity was associated with less incident AF and appeared to mediate some of the relationship between obesity and AF.
3) Hypertension. Elevated blood pressure (BP) has consistently been one of the strongest predictors of AF so the authors argue strongly for control in those with already elevated BP and for prevention in those without known hypertension (HTN). There is also a well-established association between HTN and increased risk of AF and complications of AF, particularly stroke.
4) Cholesterol. There are some studies that suggest that low HDL cholesterol may increase risk of AF but others have not found this association. Results from studies of statins and of fish oils in AF prevention also have been mixed. Overall, the data on control of dyslipidemia and AF risk is somewhat inconclusive except in one setting: AF prophylaxis during the perioperative period for cardiac surgery. In such cases, statin use in patients with known AF has been shown to be associated with a lower risk of perioperative recurrence.
5) Diabetes. It is well established that diabetes is an independent risk factor for AF and treating those with prediabetes is critical to preventing development of AF. However, there is not enough evidence to suggest that any particular strategy for diabetes management (ie, oral agents vs insulin) directly affects the risk for future AF. Optimal disease management and prevention of macrovascular complications, however, may indirectly impact the risk.
6) Obstructive sleep apnea (OSA). OSA is one of the most important risk factors for development of AF and in a multivariate analysis, had a greater association with AF than BMI, HTN, or diabetes. Treating OSA aggressively is a cornerstone of AF prevention, especially in those who have undergone cardioversion or ablation. In addition, if a rhythm control strategy is being considered, the evidence suggests routine OSA screening to maximize chances of success.
7) Tobacco/Alcohol. Alcohol has been related to AF risk in a dose-dependent manner (hence the term “holiday heart”) but the evidence for tobacco use and risk of incident AF is conflicting. Unfortunately, it is also not clear whether alcohol or tobacco cessation decreases AF burden. Nonetheless, the authors suggest both strategies should be part of an overall approach to lower AF risk.
Miller JD, Aronis KN, Chrispin J,et al. Obesity, exercise, obstructive sleep apnea, and modificable atherosclerotic cardiovascular disease risk factors in atrial fibrillation. J Am Coll Cardiol. 2015;66:2899-2906. doi:10.1016/j.jacc.2015.10.047. (Free full text)