Atrial fibrillation detected at screening is not a benign condition: outcomes in screen-detected versus clinically detected atrial fibrillation. Results from the Prevention of Renal and Vascular End-stage Disease (PREVEND) study.

Aims: It is unknown whether screen-detected atrial fibrillation (AF) carries cardiovascular risks similar to clinically detected AF. We aimed to compare clinical outcomes between individuals with screen-detected and clinically detected incident AF.

Methods: We studied 8265 participants (age 49 ± 13 years, 50% women) without prevalent AF from the community-based Prevention of Renal and Vascular End-stage Disease (PREVEND) study. By design of the PREVEND study, 70% of participants had a urinary albumin concentration >10 mg/L. Participants underwent 12-lead ECG screening at baseline and every 3 years. AF was considered screen-detected when first diagnosed during a study visit and clinically detected when first diagnosed during a hospital visit. We analysed data from the baseline visit (1997-1998) up to the third follow-up visit (2008). We used Cox regression with screen-detected and clinically detected AF as time-varying covariates to study the association of screen-detected and clinically detected AF with all-cause mortality, incident heart failure (HF) and vascular events.

Results: During a follow-up of 9.8 ± 2.3 years, 265 participants (3.2%) developed incident AF, of whom 60 (23%) had screen-detected AF. The majority of baseline characteristics were comparable between individuals with screen-detected and clinically detected AF. Unadjusted, both screen-detected and clinically detected AF were strongly associated with mortality, incident HF, and vascular events. After multivariable adjustment, screen-detected and clinically detected AF remained significantly associated with mortality (HR 2.21 (95% CI 1.09 to 4.47) vs 2.95 (2.18 to 4.00), p for difference=0.447) and incident HF (4.90 (2.28 to 10.57) vs 3.98 (2.49 to 6.34), p for difference=0.635). After adjustment, screen-detected AF was not significantly associated with vascular events, whereas clinically detected AF was (1.12 (0.46 to 2.71) vs 1.92 (1.21 to 3.06), p for difference=0.283).

Conclusion: Screen-detected incident AF was associated with an increased risk of adverse outcomes, especially all-cause mortality and incident HF. The risk of outcomes was not significantly different between screen-detected AF and clinically detected AF.