Patients with cancer and atrial fibrillation treated with doacs: A prospective cohort study

Background: Limited data are available on the use of direct oral anticoagulants (DOACs) in patients with cancer and atrial fibrillation (AF). Methods: Consecutive patients with non-valvular AF treated with DOACs were enrolled in a prospective cohort with the aim of evaluating thromboembolic (ischemic stroke or transient ischemic attack or systemic embolism) and major bleeding (MB) events according to presence and type of cancer. The risk of study outcomes over time was compared using Kaplan-Meier method and log-rank test or Cox proportional hazards regression. Results: 2304 patients with non-valvular AF receiving DOACs were enrolled and 16 excluded: 2288 analysed of whom 289 (12.6%) had cancer. Gastrointestinal (21%), genitourinary (15%), prostate (15%), haematological (14%), breast (13%), and lung (8%) were the more frequent sites of cancer. After a mean follow-up of 451 days, thromboembolic events occurred in 2.1% and 0.8% patient-year of cancer and non-cancer patients (adjusted-HR 2.58, 95% CI 1.08-6.16, p = 0.033). The rate of MB was 6.6% and 3.0% patient-year in cancer and non-cancer patients (adjusted-HR 2.02, 95% CI 1.25-3.27, p = 0.004). The differences in bleeding were mainly accounted for by bleeding at gastrointestinal and genitourinary sites. No significant differences were found concerning the rates of non-cancer-related mortality, fatal bleeding or fatal thrombotic events. Conclusions: In this study, the higher bleeding risk found in cancer compared to non-cancer patients was mainly due to an excess of bleeding at gastrointestinal and at genitourinary sites. Larger studies on the optimal management of cancer patients with AF are needed.