Net benefit of oral anticoagulants in patients with atrial fibrillation and active cancer: a nationwide cohort study

Aims To estimate the net cerebrovascular benefit of prophylactic treatment with oral anticoagulants (OACs) in patients with atrial fibrillation (AF) and active cancer. Methods and results We included all Swedish patients who had been diagnosed with AF in a hospital or in a hospital-associated outpatient unit between 1 July 2005 and 1 October 2017. Patients with active cancer (n = 22 596) and without cancer (n = 440 848) were propensity score matched for the likelihood of receiving OACs at baseline. At baseline, 38.3% of cancer patients with AF and high stroke risk according to CHA2DS2-VASc score received OACs. There was a net benefit of OACs, assessed by the composite outcome of ischaemic stroke, extracranial arterial thromboembolism, all major bleedings, and death, both among patients with active cancer [hazard ratio (HR): 0.81, confidence interval (CI): 0.78-0.85] and among patients without cancer (HR: 0.81, CI: 0.80-0.82). When limiting follow-up to 1 year to minimize the effects of possible treatment cross-over and additionally accounting for death as a competing risk in cancer patients, a net cerebrovascular benefit regarding ischaemic stroke or intracranial bleeding was observed for OACs [subhazard ratio (sHR): 0.67, CI: 0.55-0.83]. A net cerebrovascular benefit was also seen for non-vitamin K antagonist OACs over warfarin after competing risk analyses in cancer patients (sHR: 0.65, CI: 0.48-0.88). Conclusion Patients with AF and active cancer benefit from OAC treatment.