Abstract Aims This study aimed to determine the impact of heart failure (HF) on clinical outcomes in patients with atrial fibrillation (AF). Methods and results We analysed data from Polish participants of the EURObservational Research Programme‐AF General Long‐Term Registry. The primary endpoint was all‐cause death, and the secondary endpoints included hospital readmissions, cardiovascular (CV) interventions, thromboembolic and haemorrhagic events, rhythm control interventions, and other CV or non‐CV diseases development during one‐year follow up. Overall, 688 patients with available data on HF were included into analysis; 51% (n = 351) had HF; of these 48% (n = 168) had reduced ejection fraction (HFrEF), 22% (n = 77) mid‐range EF (HFmrEF), and 30% (n = 106) preserved EF (HFpEF). Compared with patients without HF, those with HF had higher mortality rate (aHR 5.61; 95% CI 1.94–16.22, P