Incident heart failure in patients with screening-detected atrial fibrillation: a post hoc analysis of the STROKESTOP and STROKESTOP II studies.

BACKGROUND AND AIM: Atrial fibrillation is associated with increased risks of stroke, heart failure, and death. While stroke prevention is a key focus, heart failure is more frequent and a major contributor to mortality in atrial fibrillation. This study aimed to assess the incidence and timing of heart failure in screening-detected atrial fibrillation. METHODS: This post hoc analysis included participants without prior heart failure from the STROKESTOP and STROKESTOP II randomized screening studies, in which individuals aged 75-76 years were invited to ECG-based atrial fibrillation screening. Incident heart failure diagnoses were obtained from national registries. Incidence rates were calculated per 100 person-years, and Cox regression was used to estimate hazard ratios (HRs). RESULTS: In STROKESTOP, 23% of participants with screening-detected atrial fibrillation developed heart failure (3.76 per 100 person-years), compared with 4.43 in patients with known atrial fibrillation and 1.08 in patients without atrial fibrillation. Screening-detected atrial fibrillation was associated with a threefold higher heart failure risk vs. no atrial fibrillation (adjusted HR 3.19) and a risk comparable to known atrial fibrillation (adjusted HR 2.86). In STROKESTOP II, 20% developed heart failure (4.19 per 100 person-years), compared with 3.52 in known atrial fibrillation and 0.93 without atrial fibrillation. Screening-detected atrial fibrillation was associated with a fourfold higher heart failure risk vs. no atrial fibrillation (adjusted HR 4.73) and a higher risk than known atrial fibrillation (adjusted HR 2.59). CONCLUSION: Screening-detected atrial fibrillation is associated with a high risk of heart failure, comparable to known atrial fibrillation, and is not a benign condition.