Objectives: To date, evidence on optimal anticoagulant options in patients with AF who concurrently have active cancer remains elusive. The objective of this study was To describe anticoagulant patterns among patients with a concomitant diagnosis of AF and cancer and to compare clinical outcomes associated with different anticoagulation strategy.

Methods: Data were obtained from the University of Utah and Huntsman Cancer Institute (HCI) Hospitals. Patients were included if they were 18 years old or older, had diagnosis of AF and cancer based on ICD 10 codes. Patients who did not receive anticoagulant were excluded. Outcome was type and pattern of anticoagulant. Clinical outcomes were stroke, bleeding and all-cause mortality.

Results: From October 1999-December 2020, there were 566 AF patients who concurrently had active cancer. Mean age ± standard deviation was 76.2 ± 10.7 and 57.6% were males. Mean CHA₂DS₂-VASc Score was 5.8 ±1.8. Comparing to warfarin, patients who received direct oral anticoagulants (DOACs) were associated with similar risk of stroke (adjusted hazard ratio, aHR 0.8, 95% confidence interval [CI] 0.2-2.7, P=0.67). On contrary, those who received heparin were associated with significantly higher risk of stroke comparing to warfarin (aHR 2.4, 95%CI 1.0-5.6, P=0.04). Comparing to warfarin, DOACs and heparin was associated with similar risk of overall bleeding with aHR 1.1 (95%CI 0.7-1.6, P=0.7) and aHR 1.1 (95%CI 0.6-1.7, P=0.26), respectively. Patients who received heparin but not DOACs were associated with increased risk of death as compared to warfarin, aHR 4.5 (95%CI 2.8-7.2, P<0.001) and 1.2 (95%CI 0.7-2.2, P=0.47).

Conclusions: In patients with active cancer and AF, heparin, compared to warfarin, was associated with an increased risk of stroke and all-cause mortality. Furthermore, DOACs were associated with similar risk of stroke, bleeding and death as compared to warfarin. Further prospective trials are needed to confirm these findings.