Factor Xa Inhibitors versus warfarin in patients with morbid obesity and atrial fibrillation.

Factor Xa Inhibitors have emerged as a first-line agent in the management of non-valvular atrial fibrillation (NVAF), but there is a need for additional data surrounding their use in the morbidly obese population. The purpose of this study was to evaluate whether Factor Xa Inhibitors are as safe and effective as warfarin for the treatment of NVAF in individuals with a BMI ≥ 40 kg/m2 and/or weight ≥ 120 kg. This was a multi-center retrospective cohort study comparing the use of Factor Xa Inhibitors (apixaban and rivaroxaban) to warfarin for the management of NVAF in adult patients with a BMI ≥ 40 kg/m2 and/or weight ≥ 120 kg. The primary outcomes were stroke or systemic embolism and major bleeding within 12 months. A total of 3,156 patients were included in the final analysis; 1,396 in the warfarin group and 1760 in the Factor Xa Inhibitor group. The mean weight and BMI of the overall cohort was 134.1 kg and 44.7 kg/m2, respectively. There was no difference in stroke or systemic embolism (OR 1.21, 95% CI 0.78-1.85) or major bleeding (OR 0.99, 95% CI 0.65 - 1.53) with Factor Xa Inhibitors compared to warfarin after controlling for covariates. This analysis of real-world data suggests no difference in bleeding or thrombotic outcomes for severely obese patients with NVAF taking Factor Xa Inhibitors compared to warfarin. Overall, our study adds further data to support the use of Factor Xa Inhibitors as an alternative to warfarin in severely obese patients with NVAF.

Dobry P ，McGrew K ，Yun I ，Heath R ，Shafqat A ，Ascend-Higher ，Giuliano C ... -  《-》

Efficacy and safety of direct oral factor Xa inhibitors compared with warfarin in patients with morbid obesity: a single-centre, retrospective analysis of chart data.

Because studies of direct oral anticoagulants in patients with venous thromboembolism and non-valvular atrial fibrillation have had minimal representation of morbidly obese patients (ie, body-mass index [BMI] ≥40 kg/m2), their efficacy and safety in this population are unclear. We investigated whether apixaban and rivaroxaban are as effective and safe as warfarin in morbidly obese patients. We did a single-centre, retrospective analysis of chart data for all adult patients aged at least 18 years at Montefiore Medical Center (Bronx, NY, USA) with a BMI of at least 40 kg/m2 who were prescribed apixaban, rivaroxaban, or warfarin for either venous thromboembolism or atrial fibrillation between March 1, 2013, and March 1, 2017. Patients who had both venous thromboembolism and atrial fibrillation were excluded, as were patients with indications other than atrial fibrillation and venous thromboembolism. Outcomes of recurrent venous thromboembolism, stroke, and bleeding were measured from the first prescription date to the earliest of a thrombotic event, medication discontinuation, death, or end of study on June 30, 2017. Analyses were stratified by anticoagulation indication and adjusted for comorbidities, CHA2DS2-VASc score, and age where appropriate. Outcome rates were compared using Pearson's χ2 or Fisher's exact test. Time-to-event analyses accounting for length of follow-up were used to compare risks of outcomes. We obtained data for 795 patients: 150 prescribed apixaban, 326 rivaroxaban, and 319 warfarin. In 366 patients prescribed an anticoagulant for venous thromboembolism, the incidence of recurrent venous thromboembolism was similar between the apixaban, rivaroxaban, and warfarin cohorts (1/47 [2·1%, 95% CI 0·0-6·3], 3/152 [2·0%, 0·0-4·2], and 2/167 [1·2%, 0·0-2·9], respectively; p=0·74). Incidence of major bleeding in this patient group was also similar between the treatment cohorts (1/47 patients on apixaban [2·1%, 95% CI 0·0-6·3], 2/152 on rivaroxaban [1·3%, 0·0-3·1], and 4/167 on warfarin [2·4%, 0·1-4·7]; p=0·77). In 429 patients prescribed an anticoagulant for atrial fibrillation, incidence of stroke was similar between the treatment cohorts (1/103 patients on apixaban [1·0%, 95% CI 0·0-2·9], 4/174 on rivaroxaban [2·3%, 0·1-4·5], and 2/152 on warfarin [1·3%, 0·0-3·1], p=0·71). In this patient group, major bleeding occurred in 3/103 patients on apixaban (2·9%, 95% CI 0·0-6·2), 5/174 on rivaroxaban (2·9%, 0·4-5·4), and 12/152 on warfarin (7·9%, 3·6-12·2); p=0·063. Time-to-event analyses showed that risk of all outcomes in patients with venous thromboembolism, and stroke and composite bleeding in patients with atrial fibrillation, were similar between the anticoagulant cohorts. Our retrospective study provides further evidence of similar efficacy and safety between the direct oral anticoagulants apixaban and rivaroxaban, and warfarin in morbidly obese patients with atrial fibrillation and venous thromboembolism. These data, if confirmed in prospective studies, might enable patients with a BMI of at least 40 kg/m2 to benefit from more convenient, and possibly safer, anticoagulants. None.

Kushnir M ，Choi Y ，Eisenberg R ，Rao D ，Tolu S ，Gao J ，Mowrey W ，Billett HH ... -  《Lancet Haematology》

Risk of Major Bleeding, Stroke/Systemic Embolism, and Death Associated With Different Oral Anticoagulants in Patients With Atrial Fibrillation and Severe Chronic Kidney Disease.

Xu Y ，Ballew SH ，Chang AR ，Inker LA ，Grams ME ，Shin JI ... -  《Journal of the American Heart Association》

Rivaroxaban Versus Warfarin for Stroke Prevention and Venous Thromboembolism Treatment in Extreme Obesity and High Body Weight.

Perales IJ ，San Agustin K ，DeAngelo J ，Campbell AM ... -  《-》

Effectiveness and Safety of Apixaban Versus Warfarin in Obese Patients with Nonvalvular Atrial Fibrillation Enrolled in Medicare and Veteran Affairs.

Real-world studies have evaluated the use of anticoagulants in obese patients with nonvalvular atrial fibrillation (NVAF), but they have been limited by sample size or the use of diagnosis codes on claims to define obesity. This retrospective study used body weight data of ≥100 kg or a body mass index of ≥30 kg/m2 to identify elderly (aged ≥65 years) NVAF patients with obesity in dually enrolled Veterans Affairs and fee-for-service Medicare patients. It evaluated the risk of stroke/systemic embolism (SE) and major bleeding (MB) in patients that initiated apixaban versus warfarin. Stabilized inverse probability treatment weighting was used to balance the baseline characteristics between patients prescribed apixaban and warfarin in obese patients. Cox models were used to evaluate the relative risk of stroke/SE and MB. Overall, 35.9% (n = 26,522) of the NVAF population were obese, of which 13,604 apixaban and 12,918 warfarin patients were included. After inverse probability treatment weighting, patient characteristics were balanced. The mean age was 75 years, the mean CHA2DS2-VASc score (Congestive Heart Failure, Hypertension, Age ≥75 [Doubled], Diabetes Mellitus, Prior Stroke or Transient Ischemic Attack [Doubled], Vascular Disease, Age 65-74, Female) was 3.8, the mean HAS-BLED (Hypertension, Abnormal Renal/Liver Function, Stroke, Bleeding History or Predisposition, Labile INR, Elderly, Drugs/Alcohol Concomitantly) Score was ∼2.6, and >98% of patients were males. Obese apixaban patients were associated with a similar risk of stroke/SE (hazard ratio: 0.82; 95% confidence interval: 0.66 to 1.03) and a significantly lower risk of MB (hazard ratio: 0.62; 95% confidence interval: 0.54 to 0.70) versus warfarin. No significant interaction was observed between treatment and obesity status (nonobese, obese/nonmorbid, obese/morbid) for stroke/SE (interaction p = 0.602) or MB (interaction p = 0.385). In obese patients with NVAF, apixaban was associated with a similar risk of stroke/SE and a significantly lower risk of MB versus warfarin.

Deitelzweig S ，Sah J ，Kang A ，Russ C ，Preib M ，Dhamane AD ，Ratiu A ，Cato M ，Alfred T ，Levi E ，Di Fusco M ... -  《-》