Type 2 diabetes increases the long‐term risk of heart failure and mortality in patients with atrial fibrillation

Aims Impact of type 2 diabetes mellitus (T2DM) on non‐thromboembolic outcomes in atrial fibrillation (AF) is insufficiently explored. This prospective cohort study of AF patients aimed (i) to analyse the association between T2DM and heart failure (HF) events (including new‐onset HF), and all‐cause and cardiovascular mortality, (ii) to assess the impact of baseline T2DM treatment on outcomes, and (iii) to explore characteristics of new‐onset HF phenotypes in relation to T2DM status. Methods and results Of 1803 AF patients (515/1288, with/without prior HF), 389 (22%) had T2DM at baseline. After 5 years of median follow‐up, T2DM patients had an 85% greater risk of HF events [adjusted hazard ratio (aHR) 1.85; 95% confidence interval (CI) 1.51–2.28; P