DOACs safe and effective in preventing VTE in obese patients
This retrospective study showed no difference in the recurrence of VTE, PE and DVT occurrence, and bleeding events within 12 months after an acute VTE in obese patients treated with either a DOAC or warfarin.
Effectiveness and Safety of Direct Oral Anticoagulants versus Warfarin in Obese Patients with Acute Venous ThromboembolismLiterature - Coons JC, Albert L, Bejjani A et al., - Pharmacotherapy. 2020. doi: 10.1002/phar.2369.
Introduction and methods
Data on the use of direct oral anticoagulants (DOACs) in obese patients are limited to post-hoc subgroup analyses, as no clinical trials have specifically studied these medications in obese patients [1,2]. Data from pharmacokinetic (PK) and pharmacodynamic studies of DOAC use in obese patients are also limited, but suggest modest effects of obesity on PK parameters, such as lower drug exposure and diminished peak concentrations [1]. Guidance statements advice against DOAC use in patients with a body weight >120 kg or a BMI >40 kg/m², due to lack of clinical information [2]. When VKAs can not be used in patients >120 kg or with a BMI ≥35kg/m², DOAC may be suggested, according to a consensus statement [3]. This study aimed to evaluate the effectiveness and safety of DOACs vs warfarin in obese patients with acute venous thromboembolism (VTE).
This retrospective matched cohort study included 1840 patients with acute VTE and a body weight between 100 and 300 kg, and who did not have a diagnosis of atrial fibrillation or atrial flutter. 632 Patients received a DOAC (580 patients [91.8%] received rivaroxaban, 33 patients [5.2%] apixaban and 19 patients [3%] dabigatran). 1208 Patients received warfarin. Patients in the warfarin group were matched in a 2:1 ratio to patients in the DOAC group.
The primary outcome was recurrence of VTE within 12 months of the index admission date. Secondary outcomes were bleeding, pulmonary embolism (PE) and deep vein thrombosis (DVT) within 12 months of the index admission date.
Main results
- The median body weight was 115 kg in the DOAC group and 116 kg in the warfarin group. Median BMI was 38.8 kg/m² in the DOAC group and 39.2 kg/m² in the warfarin group. 41.8% And 41.1% of the patients had a body weight > 120 kg in the DOAC and warfarin groups, respectively. In the DOAC group, 26.9% of the patients had a BMI between 35 and 39 kg/m² and 43.6% had a BMI >40, in the warfarin group was this 23.7% and 45.3%, respectively.
- 6.5% Of the patients (41 patients) in de DOAC group and 6.4% (77 patients) in the warfarin group met the primary outcome of VTE recurrence within 12 months (HR: 1.03, 95%CI:0.71-1.50, P=0.93).
- PE occurred in 3.7% and 3.8% in the DOAC and warfarin groups, respectively (P=0.94). DVT occurred in 3% and 3.5% in the DOAC and warfarin groups, respectively (P=0.56).
- Bleeding within 12 months occurred in 1.7% of the patients (11 patients) in the DOAC group and in 1.2% (14 patients) in the warfarin group (P=0.31). Among bleeding events, gastrointestinal and genitourinary bleedings were most common in both groups.
Conclusion
This retrospective matched cohort study in patients with acute VTE and a body weight between 100 and 300 kg, showed similar rates for VTE recurrence, occurrence of PE and DVT and bleeding events within 12 months of the index admission date in patients that were treated with a DOAC compared to those treated with warfarin.
References
1. Upreti VV, Wang J, Barrett YC, et al. Effect of extremes of body weight on the pharmacokinetics, pharmacodynamics, safety and tolerability of apixaban in healthy subjects. Br J Clin Pharmacol 2013;6:908-16.
2. Martin K, Beyer-Westendorf J, Davidson BL, Huisman MV, Sandset PM, Moll S. Use of the direct oral anticoagulants in obese patients: guidance from the SSC of the ISTH. Journal of thrombosis and haemostasis. JTH 2016;6:1308-13.
3. Burnett AE, Mahan CE, Vazquez SR, Oertel LB, Garcia DA, Ansell J. Guidance for the practical management of the direct oral anticoagulants (DOACs) in VTE treatment. Journal of thrombosis and thrombolysis 2016;1:206-32.