Frequent premature atrial complexes predict new occurrence of atrial fibrillation and adverse cardiovascular events

Abstract

To investigate the relation between baseline frequency of premature atrial complexes (PACs) and new atrial fibrillation (AF) and adverse cardiovascular events. Four hundred and twenty-eight patients without AF or structural heart disease undergoing 24 h electrocardiography monitoring for palpitations, dizziness, or syncope were recruited. One hundred and seven patients with number of PACs at the top quartile (i.e. > 100PACs/day) were defined to have frequent PACs. After 6.1-year follow-up, 31 patients (29%) with frequent PACs developed AF compared with 29 patients (9%) with PACs ≤ 100/day (P< 0.01). Cox regression analysis revealed that frequent PACs [hazard ratio (HR): 3.22 (95% confidence interval (CI): 1.9-5.5; P< 0.001)], age >75 years (HR: 2.3; 95% CI: 1.3-3.9; P= 0.004), and coronary artery disease (HR: 2.5; 95% CI: 1.4-4.4; P= 0.002) were independent predictors for new AF. Concerning the composite endpoint (ischaemic stroke, heart failure, and death), patients with frequent PACs were more at risk than those without (34.5 vs. 19.3%) (HR: 1.95; 95% CI: 1.37-3.50; P= 0.001). Cox regression analysis showed that age >75 years (HR: 2.2; 95% CI: 1.47-3.41; P< 0.001), coronary artery disease (HR: 2.2, 95% CI: 1.42-3.44, P< 0.001), and frequent PACs (HR: 1.6; 95% CI: 1.04-2.44; P= 0.03) were independent predictors for the secondary composite endpoint. Frequent PACs predict new AF and adverse cardiovascular events.