A prospective Swedish observational study assessed the level of alcohol consumption and the risk of atrial fibrillation (see DOI: org/10.1016/j.jacc.2014.03.048). In this study, 79,019 men and women from 2 large population-based cohorts (the Cohort of Swedish Men and the Swedish Mammography Cohort), initially free of atrial fibrillation (AKA afib), completed alcohol ingestion questionnaires (as part of 350-item questionnaire), followed for >12 years (with 860K person-years of followup).
Findings:
–7245 incident cases of afib
–Compared with current drinkers of <1 drink/week (with 12 grams alcohol/drink), multivariate relative risks were:
–1-6 drinks/wk: RR=1.01 (0.94-1.09)
–7-14 drinks/wk: RR=1.07 (0.98-1.17)
–15-21 drinks/wk: RR=1.14 (1.01-1.28)
–>21 drinks/wk: RR=1.39 (1.22-1.58)
–No difference in association with alcohol by gender. Above RRs were similar if excluded binge drinkers (>5 drinks on single occasion)
–In their meta-analysis of 7 prior studies with 12554 incident cases of afib, they found relative risks:
–for 1 drink/day: RR=1.08 (1.06-1.10)
–for 2 drinks/day: RR=1.17 (1.13-1.21)
–for 3 drinks/day: RR=1.26 (1.19-1.33)
–for 4 drinks/day: RR=1.36 (1.27-1.46)
–for 5 drinks/day: RR=1.47 (1.34-1.61)
So, pretty impressive association in both their study and the meta-analysis that moderate alcohol consumption is associated with the development of atrial fibrillation, and that this association is not just with binge drinking (“holiday heart”). However, on the other side, is the lower risk of coronary artery disease with moderate alcohol consumption (though there is argument that these studies showing benefit of alcohol are pretty biased). Seems reasonable to me (though untested) that people at high risk of developing afib (e.g., some combination of advanced age, systolic hypertension, heart failure, increased BMI, mitral valve disease, frequent PACs or increased PR interval) be advised to avoid alcohol on a regular basis.
Geoff