Atrial fibrillation detected at screening is not a benign condition - a comparison of clinical outcomes in screen-detected vs. hospital-detected atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Dutch Heart Foundation Background Screening for atrial fibrillation (AF) improves detection of AF. However, it is unknown whether AF detected at screening carries risks similar to clinically detected AF, and if it should be treated similarly. Purpose We aimed to compare clinical outcomes in individuals with screen-detected vs. hospital-detected incident AF. Methods We studied 8265 individuals (mean age 49 ± 13 years, 50% women) without prevalent AF from the population-based PREVEND (Prevention of Renal and Vascular End-Stage Disease) cohort study. By design, 70% of PREVEND participants had urinary albumin concentration ≥10 mg/l. AF was considered screen-detected when first detected on a 12-lead electrocardiogram (ECG) during one of the PREVEND study visits, and hospital-detected when first detected on a hospital ECG. Using Cox regression models with screen-detected and hospital-detected AF as time-varying covariates, we studied the association of screen-detected vs. hospital-detected AF with mortality, incident heart failure (HF), and incident cardiovascular (CV) events. Results During a mean follow-up of 9.7 years, 265 participants (3.2%) developed incident AF (mean age 62 ± 9 years, 30% women, 65% hypertension, 23% obesity, 9% diabetes, 15% history of myocardial infarction, 3% history of stroke, 2% prevalent HF). Of all incident AF cases, 60 (23%) were screen-detected and 205 (77%) hospital-detected. Baseline characteristics were generally comparable between participants with screen-detected and hospital-detected AF. A larger proportion of incident AF was screen-detected in men (26%) compared to women (15%). In univariabe analysis, both screen-detected and hospital-detected AF were strongly associated with death, incident HF, and incident CV events. After multivariable adjustment, hospital-detected AF was significantly associated with death (HR 2.95, 95% CI 2.18-4.00), incident HF (HR 3.98, 95% CI 2.49-6.34), and incident CV events (HR 1.92, 95% CI 1.21-3.06). Screen-detected AF was significantly associated with death (HR 2.21, 95% CI 1.09-4.47) and incident HF (HR 4.90, 95% CI 2.28-10.57), but not with incident CV events (HR 1.12, 95% CI 0.46-2.71). Conclusions In a population-based cohort enriched for microalbuminuria, almost a quarter of incident AF cases was first detected through ECG screening. Compared to hospital-detected AF, screen-detected AF was similarly associated with adverse outcomes. Although randomised trials are needed, this study highlights that AF screening may help decrease the general burden of CV disease.