Prediabetes Is Associated With Increased Risk of Heart Failure Among Patients With Atrial Fibrillation

OBJECTIVE To evaluate the association between prediabetes and heart failure (HF) and the association of HF with changes in glycemic status. RESEARCH DESIGN AND METHODS Patients newly diagnosed with atrial fibrillation (AF) between 2015 and 2018 were divided into three groups (normoglycemia, prediabetes, and type 2 diabetes) according to their baseline glycemic status. The primary outcome was incident HF. The Fine and Gray competing risks model was applied, with death defined as the competing event. RESULTS Among 17,943 patients with AF (mean age 75.5 years, 47% female), 3,711 (20.7%) had prediabetes, and 10,127 (56.4%) had diabetes at baseline. Over a median follow-up of 4.7 years, HF developed in 518 (14%) patients with normoglycemia, 646 (15.7%) with prediabetes, and 1,795 (17.7%) with diabetes. Prediabetes was associated with an increased risk of HF compared with normoglycemia (subdistribution hazard ratio [SHR] 1.12, 95% CI 1.03–1.22). In patients with prediabetes at baseline, 403 (11.1%) progressed to diabetes, and 311 (8.6%) reversed to normoglycemia at 2 years. Compared with remaining prediabetic, progression to diabetes was associated with an increased risk of HF (SHR 1.50, 95% CI 1.13–1.97), whereas reversion to normoglycemia was associated with a decreased risk (SHR 0.61, 95% CI 0.42–0.94). CONCLUSIONS Prediabetes was associated with an increased risk of HF in patients with AF. Compared with patients who remained prediabetic, those who progressed to diabetes at 2 years experienced an increased risk of HF, whereas those who reversed to normoglycemia incurred a lower risk of HF.