Aims This study aimed to examine the prognostic significance of a history of cancer and atrial fibrillation (AF) in antithrombotic therapy for patients with chronic heart failure (CHF). Methods and results We enrolled consecutive 4876 CHF patients (69 +/- 12 years; women, 31.9%) in our multicentre, hospital-based cohort study, the Chronic Heart Failure Analysis and Registry in the Tohoku District-2 (CHART-2), with a median follow-up of 8.7 years. Among them, 14% and 41% had a history of cancer and AF, respectively. AF patients with a history of cancer were older, more frequently men. History of cancer was not statistically associated with higher rate of composite of stroke, systemic thrombosis, and major bleeding defined by International Society on Thrombosis and Haemostasis [Fine-Gray sub-distribution hazard ratio (sHR) accounting for the competing risk of all-cause death, 0.91; 95% confidence interval (CI), 0.56-1.48; P = 0.715]. The patients with history of cancer and AF had a heightened risk for the composite of stroke, systemic thrombosis, and major bleeding (sHR, 1.64; 95% CI, 1.04-2.60; P = 0.033), especially in those aged >75 years (sHR, 2.14; 95% CI, 1.01-4.53; P = 0.046) and those with ischaemic heart disease (IHD; 2.48; 1.30-4.72; P = 0.006). Furthermore, 36% of AF patients with a history of cancer did not receive anticoagulant therapy. Conclusions The CHF patients with history of cancer and AF had higher risk for stroke, systemic thrombosis, and major bleeding, especially in the elderly and those with IHD, but considerable number of the patients did not receive anticoagulant therapy, indicating the need for better optimal anticoagulation strategy.
