(P-357) Utilization Patterns of Direct Oral Anticoagulants in Medicare Beneficiaries with Cancer and Non-valvular Atrial Fibrillation

Background: Although clinical guidelines recommend using direct oral anticoagulants (DOACs) over warfarin in patients with non-valvular atrial fibrillation (NVAF) who are at increased risk of stroke, no clear recommendations are made for patients with cancer and NVAF.

Objectives: We characterized oral anticoagulant use and patient factors associated with DOACs use in cancer patients with NVAF.

Methods: We used Surveillance, Epidemiology, and End Results (SEER)-Medicare-linked data and included patients aged ≥66 years diagnosed with cancer (breast, bladder, colorectal, esophagus, lung, ovary, kidney, pancreas, prostate, stomach, and uterus) from 2010 to 2016. We limited the cohort to individuals with a new diagnosis of NVAF following cancer diagnosis and those who did not use oral anticoagulants during the 12-months before NVAF diagnosis. We evaluated DOACs and warfarin use within 3 months after the NVAF diagnosis. Among patients who received any oral anticoagulants, we constructed a multivariable logistic regression model to determine the independent association of sociodemographic factors, cancer-related characteristics, comorbidities, risk of stroke (assessed by CHA₂DS₂-VASc score), risk of bleeding (assessed by HAS-BLED score), and co-medications with the use of DOACs compared to warfarin.

Results: Of 19,295 patients with cancer and NVAF, 7,524 (39%) used oral anticoagulants; 4,168 (21.6%) used DOACs and 3,356 (17.4%) used warfarin within 3 months after NVAF. Among patients who used oral anticoagulants (n=7,524), the use of DOACs increased from 1.3% in 2010 to 75.6% in 2016. After adjustment of all characteristics, patients with higher income per capita were more likely to use DOACS (OR 1.53, 95%CI 1.130-1.79 for the fourth quartile vs. the first quartile). A CHA₂DS₂-VASc score of ≥6 (OR 0.59, 95% CI 0.36-0.97) compared to a score of 1, reduced the likelihood, whereas HAS-BLED score of 2 (OR 1.37, 95% CI 1.01-1.88) compared to score of 1, increased the likelihood of DOACs use.

Conclusions: Among cancer patients with newly diagnosed NVAF, the use of DOACs has markedly increased from 2010 to 2016. As opposed to clinical guideline recommendations in the general population, DOACs are prescribed less often to cancer patients who are at higher risk of stroke.