Abstract 16535: EVALUATION OF NOVEL ORAL ANTICOAGULANT PRESCRIPTION PATTERNS IN A TERTIARY CARE CLINIC

Introduction:Evidence supports utilization of Direct Oral Anticoagulants (DOAC) in patients at risk for stroke or thromboembolic events in the setting of non-valvular atrial fibrillation (AF) . Unfortunately, a number of patients may be at risk of adverse outcomes related to under treatment. We sought to describe DOAC prescribing patterns at a large AF clinic and understand the rate and reasons for subclinical DOAC dosing in these patients.Methods:Baseline, and follow up data for all patients on low dose Rivaroxaban (R) (15mg OD), Dabigatran (D) (110mg BiD), and Apixaban(A) (2.5mg BiD) was collected for analysis. Patients were then stratified into one of 3 groups based on the DOAC prescribed. History of cardiovascular, renal, and hepatic disease, as well as the HAS-BLED score was obtained for all patients.Results:629 patients were included in this analysis (Mean age: 82.3?7.6 years, 68.9% Male, A: 152, D: 242, R: 210). Average HAS-BLED score was 2.4 (A: 2.5?1.1, D: 2.2?0.8, R: 2.7?1.0) for all patients. Overall 63% (A: 52%, D:75%, R: 58%) were appropriately prescribed the lower dose of DOAC. Patients who were undertreated had an average HAS-BLED score of 2.5 (A: 2.5?0.9, D: 2?0.8, R: 2.5?1.0) vs. 2.4 (A: 2.5?1.0, D: 2.3?1.0, R: 2.9?1.0) P=0.16, for patients appropriately receiving the lower dose. Of the undertreated patients 12 had prior history of stroke (A: 3, D: 3, R: 6). Reasons for dose reduction included concomitant treatment with antiplatelet agents in 33 patients (A: 5, D: 7, R: 21), age greater than 80 as a sole factor in 93 patients (A: 56, D: 0, R: 37) and elevated creatinine (Scr>130umol/L) as a sole factor in 21 patients (A: 4, D: 4, R: 13). Of the patients on reduced dose of DOAC, those on Rivaroxaban were the most likely to be undertreated (P=0.03). The most significant factor for prescription of lower DOAC dose was age greater than 80 years (P=0.001).Conclusion:A significant number of patients with non-valvular AF who have clinical indications for oral anticoagulation therapy are undertreated with DOACs. Age greater than 80 appears to be the main reason for undertreatment. This pattern is not driven by objectively higher risk of bleeding according to the patient?s HAS-BLED score.