THE EFFICACY AND SAFETY OF DIRECT ORAL ANTI-COAGULANTS IN THE PREVENTION OF CEREBROVASCULAR ACCIDENT AND VENOUS THROMBOEMBOLIC EVENTS IN PATIENTS WHO WEIGH > 120 KG OR BMI > 40 WHEN COMPARED TO WARFARIN IN THE SETTING OF AN URBAN SAFETY-NET HOSPITAL

Abstract

TOPIC: Pulmonary Vascular Disease TYPE: Original Investigations PURPOSE: In the United States, we use direct oral anticoagulant (DOAC) medications for the treatment and prevention of cerebrovascular accident (CVA) and venous thromboembolic events (VTE): pulmonary embolism (PE) and deep venous thrombosis (DVT). DOACs are a convenient alternative to vitamin K antagonists. However, the Federal Drug Administration (FDA) has approved DOAC usage in patients with body weight less than 120 kilogram (kg) or body mass index (bmi) less than 40. Our clinical observations hypothesize that patients who were outside of the FDA approved weight category, “obese”, would have similar incidences of new CVA and VTE as “normal” weight population. METHODS: All patients using warfarin or DOAC for CVA and VTE prevention seen at MetroHealth Medical Center over a 10-year period were reviewed in this retrospective study. Selection criteria were all males and females greater than the age of 18 on warfarin, rivaroxaban, apixaban or dabigatran. Exclusion criteria were pregnant females, prisoners, and patients who were noncompliant with medications, or lost to follow up. Each chart was reviewed for indication for anticoagulation, if the patient developed a CVA or VTE while on anticoagulation, then grouped by weight class and anticoagulant used. Comparisons were analyzed with chi-square and Cochran-Mantel-Hanenszel calculations. RESULTS: 467 patients were reviewed. 108 of the patients were in the warfarin “normal” and 74 in the warfarin “obese” categories. 209 patients were in the DOAC “normal” and 76 in the DOAC “obese” categories. 54.8% were female (37.6% “normal” weight and 17.2% “obese”) and 45.2 % were male (30.2% “normal” and 15% “obese”). 340 patients on anticoagulation for atrial fibrillation or atrial flutter, 115 patients for VTE, and 12 patients for other indications. New CVA occurrences were evaluated in these four populations in patients with atrial fibrillation or atrial flutter. In the “normal” warfarin category 5% (4/75) of patients had a CVA while on anticoagulation verses 2% (1/41) in the “obese” group (P=0.4631). In the “normal” DOAC category 6% (10/168) of patients had CVA while on anticoagulation verses 2% (1/56) in the “obese” group (P=0.2114). The Cochran-Mantel-Hanenszel calculation when comparing the groups showed P=0.1510, Odds Ratio of 0.3436, CI= 0.075-1.5604. New VTE occurences were reviewed in all patients. In the “normal” warfarin category 6% (7/108) of patients had evidence of new VTE while on anticoagulation verses 12% (9/74 in the “obese” category (P =0.1870). In the “normal” DOAC category 0.5% (1/209) of patients had evidence of new VTE while on anticoagulation verses 5% (4/76) patients (P=0.0064). The Cochran-Mantel-Hanenszel calculation when comparing the three groups against the DOAC “obese” group found to have a P= 0.0153, Odds Ratio of 2.8640, 95% CI = 1.1612-7.0642. CONCLUSIONS: The risk of newly diagnosed VTE is significantly higher in “obese” DOAC patients. No statistically significant difference in the risk of CVA was observed in the “obese” vs “normal”populations. CLINICAL IMPLICATIONS: Our data provides important information on the risk of VTE in obese patients on DOACs. Further research is needed before making the decision to anticoagulated this subgroup of patients with DOACs. DISCLOSURES: No relevant relationships by ASHISH ANEJA, source=Web Response No relevant relationships by Sara Ghoneim, source=Web Response No relevant relationships by Pooja Mishra, source=Web Response No relevant relationships by Srinivasa Potla, source=Web Response No relevant relationships by Charles Thomas, source=Web Response