Preventing Atrial Fibrillation: A Three-legged Stool

As the incidence of atrial fibrillation (AF) increases in step with the aging population, physicians are looking more closely at strategies to prevent the arrhythmia, as they continue to treat their patients already diagnosed. Targeting the causes, it is hoped, will help manage overall disease burden.

A recent comprehensive and thorough review in JACC highlights and categorizes prevention strategies into three major approaches, as summarized in the 2 tables and short description that follow.

Table 1. Targeting Modifiable Lifestyle Risk Factors

AF Modifiable Lifestye Factor

Relationship to AF

Clinician Intervention

Alcohol

>50% of US adults consume regularly

>21 drinks/wk increased AF by 39%.

>35 drinks/wk increased AF by 45% -90%.

In women, ≥2 drinks/day increased AF by 60%.

1.5 drinks/day increased AF by 25-46%.

Each drink/day increased AF by ~8%.

Counsel on avoiding unhealthy drinking and how even light to moderate drinking can increase AF risk.

Physical activity and cardiorespiratory fitness

Mixed data about relationship between exercise and AF.

Overall, vigorous exercise may be associated with ↑ AF; moderate activity appears protective.

Avoid sedentary lifestyle

Psychosocial

Anger, tension, hostility increase AF by 10-30%.

Panic disorder increased AF by 73%.

Job strain increased AF by 23%.

Stress triggered 54% of AF episodes.

Happiness had protective effect (88% lower risk of AF after adjustment).

Encourage positive emotions; treat depression, anxiety, stress promptly.

Smoking

Current or former smoking increased AF by 51%; risk decreases after quitting smoking.

Secondhand smoke associated with higher risk.

Up to 12% AF cases avoided with quitting smoking.

Offer smoking cessation interventions.

Healthy diet

Obesity, DM, dyslipidemia (see Table 2) associated with AF.

Counsel on healthy food choices and maintenance of healthy weight.

Next: Controlling CV Risk Factors, Treating CVD

Table 2. Controlling Cardiovascular Risk Factors and Treating Concurrent Cardiovascular Disease

AF Cardiovascular Risk Factor

Relationship to AF

Clinician Intervention

Obesity (worldwide):

14% of men
10% of women

Obesity increased AF by 49%.

BMI had linear association with AF risk – each unit increase in BMI increased AF by 4-8%.

Weight gain from 20 yrs to midlife of 16-35% increased AF 34% and >35% increased AF by 61%.

18% AF cases preventable by achieving optimal body weight.

Success of AF ablation higher with weight loss.

Achieve weight reduction:

>10% weight loss: 46% freedom from AF.

3-9% weight loss: 22% freedom from AF.

<3% weight loss:

13% freedom from AF.

Hypertension or widened pulse pressure

Every 10 mmHg increase in SBP increases AF by 11%.

Population attributable risk 14-20%.

Each 20 mmHg increase in pulse pressure (reflects aortic stiffness) increases AF by 26%.

Treat BP – ARBs and ACEIs reduce risk in structural (ie, LVH, CHF) and functional heart disease.

Diabetes

DM increases AF risk by 34%.

AF risk increases by 3% for each additional year of DM duration.

Each 1% increase HbA1c increases AF by 13% (DM pts) and 5% (nonDM pts).

Treating DM does not reduce AF risk – unclear if DM may be a “marker” of risk rather than causal.

Dyslipidemia and statins

Each 1-SD increase in LDL-C, AF risk reduced 10%.

HDL-C and TGs not thought to influence AF risk; only LDL-C and TC.

Treat dyslipidemia to prevent MI (as below).  Statins do not lower AF risk.

Obstructive sleep apnea: ≥5 apneic episodes/hr of sleep

OSA increased odds of AF 2.2X.

Cause-effect relationship between OSA and AF has been established.

In small study, CPAP reduced AF:

Untreated OSA: 82% AF recurrence.

CPAP-treated: 42% AF recurrence.

No OSA: 53% AF recurrence.

Myocardial infarction

7-12% incidence of new-onset AF after MI.

Prompt reperfusion reduces incidence.

Heart failure (HFREF, HFPEF)

~33% of CHF patients with AF.

CHF increases AF 4.5X in men and 5.9X in women.

Treat risk factors for CHF, start GDMT for CHF.

Next: Work at the population level

In addition to modifying lifestyle and treating cardiovascular risk factors, targeting AF at a population level is the third tenet of this “three-legged stool” for decreasing the burden from this growing disease. The authors advocate using risk prediction models to identify populations at the highest risk for AF. They warn, however, that even the best models only offer moderate discriminatory ability. Moreover, as the majority of AF arises from the low-risk population and risk is continuous along the spectrum, the authors suggest that clinicians ought to focus on making small advances in the treatment of risk factors as outlined above. 

They conclude that even incremental improvements in the above factors will shift the overall distribution of AF to decrease both the prevalence and the incidence over time. To decrease the morbidity from this disease, the focus has to now start becoming disease prevention, not just disease management.

Source:

Du X, Dong J, Ma C. Is atrial fibrillation a preventable disease?  J Am Coll Cardiol. 2017;  69:1968-1982; DOI: 10.1016/j.jacc.2017.02.020.