Excessive supraventricular ectopic activity and risk of incident atrial fibrillation in a consecutive population referred to ambulatory cardiac monitoring

Background Excessive supraventricular ectopic activity (ESVEA), defined as ≥720 premature atrial contractions (PAC) per day or any runs of ≥20 PACs, has been proposed as a surrogate marker for paroxysmal atrial fibrillation (PAF). Objective We aimed to estimate the prognostic impact of ESVEA on the future development of PAF in consecutive patients referred to ambulatory cardiac monitoring. Methods The cohort consists of a population with comorbidities referred to 48-hour ambulatory electrocardiogram aged 30–98 (n = 1316) between 2009 and 2011. After exclusion of known or current atrial fibrillation (AF) (n = 527) and patients with pacemakers (n = 7), 782 patients were included, with a median follow-up of 8.1 years. Events of incident AF and death were retrieved from patient records. Results Mean age was 58.6 ± 15.5 years and 56.5% were women. A total of 101 patients had ESVEA at baseline (12.9%). During follow-up, 69 (8.9%) developed incidental AF. Twenty-three patients with ESVEA developed AF (23%). Incidence rate of AF in patients with and without ESVEA was 37.1/1000 person-years and 9.1 per 1000 person-years, respectively ( P < .001). ESVEA was associated with incident AF after adjustment for potential confounders in Cox regression analysis (hazard ratio [HR]: 2.39; 95% confidence interval [CI]: 1.40–4.09) and in competing risk analysis with death as competing risk (subdistribution HR: 2.35; 95% CI: 1.30–4.17). Conclusion ESVEA increases the risk of incident AF substantially in a population referred to ambulatory cardiac monitoring.