Less alcohol = less atrial fibrillation
Alcohol Abstinence in Drinkers with Atrial Fibrillation. N Engl J Med 2020; 382:20-28.
Atrial fibrillation (AF) is the most common arrhythmia and is associated with increased risk of stroke, heart failure and death. Most patients with atrial fibrillation require anticoagulation to reduce the risk of stroke. The stroke risk is assessed with CHA2DS2-VASc score (1 point for heart failure, hypertension, diabetes, vascular disease, age >65 and female sex, 2 points for stroke/TIA and age >75); anticoagulation is usually recommended in men with score 1 and more and women with score 2 and more. The prevalence of atrial fibrillation is increasing due to ageing population and lifestyle factors including increase in obesity and physical inactivity.
Alcohol was always suspected to be one of the strongest driving forces of atrial fibrillation and cardiologists have been recommending reduced intake for some time, but until recently there was no clinical trial to support this. That has now changed thanks to the team led by Dr Voskoboinik from Alfred Hospital, Melbourne, Australia, who organised a multicentre randomised controlled trial ETOH-AF (Exploring The link between alcOhol and Atrial Fibrillation recurrence). It was a remarkable trial carried out without industry support and targeting lifestyle change rather than medication.
The study entered 140 patients (mean age 62 years) with paroxysmal or persistent atrial fibrillation who had been consuming at least 10 drinks per week. Their mean weekly intake was 17 drinks. 70 patients were assigned to an abstinence group and another 70 patients were counselled to continue their alcohol consumption as usual.
In the abstinence group, only 43 patients (61%) actually gave up alcohol completely during the study, but even so, overall 86% of them were able to dramatically reduce alcohol intake by more than 70%.
At 6 months, recurrent AF was seen in 37 patients in the abstinence group and 51 in the control group, for an adjusted hazard ratio (HR) of 0.52 (95% CI, 0.30 - 0.89; P = 0.014). Percentage of time spent in atrial fibrillation was also significantly lower in the abstinence group. Weight and body-mass index decreased significantly in the abstinence group (P < 0.001 for both); they rose significantly in the control group. Blood pressure also fell significantly in the abstinence group.
Motivated patients, who are regular drinkers and have atrial fibrillation, can therefore cut their chances of AF recurrence by almost half if they stop drinking, or at least substantially lower their alcohol intake. The study suggests that a significant reduction in alcohol intake reduces not only AF burden and severity of symptoms but also lowers blood pressure and reduces weight. It was not necessary to completely abstain from alcohol - although that may be ideal - as long as the reduction in drinking was significant. A complete abstinence may not be a realistic goal anyway; the study screened around 700 patients - and almost 500 refused to participate because they wouldn’t agree to be potentially allocated to the abstinence group.