Atrial fibrillation is associated with an increased risk of myocardial infarction: Insights from a meta-analysis

Abstract

Background and aimsThe presence of atrial fibrillation (AF) markedly increases the risk of stroke and mortality in patients. Whether AF is a risk factor for myocardial infarction (MI) is discrepant from current studies. The aim of this meta-analysis was to ascertain the association of AF with incident MI. MethodsStudies were identified through PubMed, CENTRAL, EMBASE, reviews and reference lists of relevant papers. Results of the MI outcome were presented as hazard ratio (HR) and 95% confidence interval (CI). Statistical analyses were performed with Stata 12.0 (Stata Corp LP, College Station, Texas, USA). ResultsTwelve studies, with a total of 169,306 patients, were included in the analysis. AF was associated with a 47% increased risk of MI (HR:1.47; 95% CI: 1.21–1.80; p = 0.000; I2 = 84.1%), while in patients free of coronary heart disease at baseline the risk could be increased by 71% (HR:1.71; 95% CI: 1.36–2.14; p = 0.000; I2 = 83.1%). Moreover, patients with AF had higher MI risk in the studies with lower mean age (<60 years) (HR:1.66; 95% CI: 1.26–2.20; p = 0.000; I2 = 82.9%) than in the studies with higher mean age (≥60 years) (HR:1.35; 95% CI: 1.00–1.82; p = 0.000; I2 = 84.9%). Sex difference also existed, and the association between AF and MI was stronger in women (HR:2.02; 95% CI: 1.60–2.56; p = 0.017; I2 = 61.0%) than in men (HR:1.44; 95% CI: 1.13–1.84; p = 0.000; I2 = 76.1%). ConclusionsAF is associated with an increased risk of incident MI, especially in patients free of coronary heart disease at baseline, young patients and women. The findings need confirmation in well-designed observational trials.