In atrial fibrillation (AF) patients, future heart failure (HF) events were shown to be predicted by increased NT‐proBNP (N‐terminal pro‐B‐type natriuretic peptide) levels regardless of the presence of HF. This observation promotes routine quantification of NT‐proBNP in the evaluation of AF cases.

• This study included patients with cardiovascular conditions who had clinical assessment, 7‐day ECG monitoring, and echocardiography to diagnose AF and HF, and NT‐proBNP was centrally quantified.

• Follow‐up data were present in 1,616 of 1,621 patients (99.7%) and analysis was done at 2.5 years (median age, 70 [interquartile range, 60–78] years; 40% women).

• In patients with neither AF nor HF, HF hospitalization or cardiovascular death rose from 36 of 488 (3.2/100 person‐years), to 55 of 354 (7.1/100 person‐years) in AF only cases, 92 of 369 (12.1/100 person‐years) in HF only cases, and 128 of 405 (17.7/100 person‐years) in those with AF plus HF.

• Higher NT‐proBNP levels predicted the outcome in those with AF only (C‐statistic, 0.82) as well as in other phenotype groups (C‐statistic in AF plus HF, 0.66).