Subclinical atrial fibrillation and the risk of heart failure: insights from ARTESiA

AIMS: Heart failure (HF) and clinical atrial fibrillation are closely linked, but the relationship between device-detected subclinical atrial fibrillation (SCAF) and HF is unclear. We aimed to determine incidence and clinical risk factors for HF events among patients with SCAF. METHODS: We included 3986 patients from the ARTESiA (Apixaban for the Reduction of Thromboembolism in Patients with Device-Detected Subclinical Atrial Fibrillation) trial. ARTESiA investigated the effect of apixaban versus aspirin for stroke prevention in patients with episodes of SCAF ≤24 hours. In this secondary analysis, we explored the number and duration of SCAF episodes at baseline as risk markers for HF hospitalization or HF-related death. SCAF progression was analysed as a time-dependent covariate and defined as the development of SCAF >24 hours or clinical atrial fibrillation. RESULTS: Over a mean follow-up of 4.1 ± 1.7 years, SCAF progression was observed in 1244 patients (31%). Heart failure hospitalization or HF-related death occurred in 515 (13%) patients at a rate of 3.3 [95% confidence interval (CI) 3.1-3.6] per 100 person-years. A total of 172 HF-related events occurred after SCAF progression (7.2 events, 95% CI 6.2-8.3, per 100 PY). SCAF progression was an independent risk factor for HF hospitalization or HF-related death (hazard ratio 2.72, 95% CI 2.24-3.31). CONCLUSION: Heart failure hospitalization and HF-related death are common in patients with SCAF. Progression to longer SCAF episodes or clinical AF were associated with HF events, but episodes