Alcohol abstinence delays AF recurrence

Abstaining from alcohol may reduce the risk of atrial fibrillation (AF) recurrence in individuals who regularly consume alcohol, according to a small study from Australia.

“[A]mong regular drinkers, a substantial reduction in alcohol consumption by patients with symptomatic AF was associated with a reduction in recurrence of AF and a reduced proportion of time spent in AF,” said the researchers. “Regular alcohol consumption is a potentially modifiable risk factor for AF.”

A total of 140 adults (mean age 62 years, 85 percent male) with symptomatic paroxysmal or persistent AF in sinus rhythm who consumed ≥10 standard alcoholic drinks* per week were randomized 1:1 to continue with their regular alcohol consumption (control group) or abstain from alcohol for 6 months. Individuals with alcohol dependence or abuse, left ventricular ejection fraction <35 percent, clinically significant non-cardiac conditions, or psychiatric disorders were excluded.

Both groups reduced their alcohol intake over the study period, from 16.8 to 2.1 drinks/week in the abstinence group (87.5 percent reduction) and from 16.4 to 13.2 drinks/week in the control group (19.5 percent reduction).

After a 2-week blanking period, fewer individuals in the abstinence group experienced an AF recurrence, defined as a ≥30 second episode of atrial tachyarrhythmia, compared with the control group at 6 months (53 percent vs 73 percent). [N Engl J Med 2020;382:20-28]

Time to AF recurrence was significantly longer in the abstinence compared with the control group (hazard ratio [HR], 0.55, 95 percent confidence interval, 0.36–0.84; p=0.005).

There was also a significantly lower AF burden, defined as the percentage of time a patient was in AF during the 6-month follow-up period, in the abstinence than the control group (median percent of time in AF, 0.5 percent vs 1.2 percent; p=0.01).

A smaller proportion of patients in the abstinence than control group experienced moderate or severe symptoms of AF (according to EHRA** classification) at 6 months (10 percent vs 32 percent).

Post hoc analysis showed that individuals who drank 1–9 drinks/week or ≥10 drinks/week, regardless of group, had a higher risk of AF recurrence than those who were completely abstinent (HR, 2.1 and HR, 2.3, respectively).

The researchers suggested that there may be multiple mechanisms behind the effect of alcohol abstinence on reduced AF recurrence, including via weight loss. In this study, at 6 months, individuals in the abstinence group had experienced greater weight loss than those in the control group (mean difference, -3.7 kg).

“Since epicardial fat has proarrhythmic properties that are mediated by inflammation and profibrotic paracrine effects, reduction in epicardial fat through weight loss may mitigate these proarrhythmic effects,” the researchers said.

A potential reduction in blood pressure and subsequently hypertension with alcohol abstinence could also have some influence, they added.

The applicability of alcohol abstinence needs to be addressed, they said, noting that a majority of the participants initially identified for study inclusion declined to be abstinent. Furthermore, some studies have shown a benefit of light-to-moderate alcohol intake on certain cardiovascular outcomes such as myocardial infarction and stroke. [Circulation 2016;133:979-987] “[P]otential cardiovascular benefits of modest alcohol consumption must be reconciled with the potential for atrial proarrhythmia,” the researchers noted.