A single center retrospective cohort study evaluating use of direct oral anticoagulants (DOACs) in morbidly obese veteran population

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

PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Efficacy and Safety of Direct Oral Anticoagulants versus Warfarin in Obese Patients (BMI ≥ 30 kg/m2) with Atrial Fibrillation or Venous Thromboembolism: An Updated Systematic Review and Meta-Analysis

Background: Real-world data show limited utilization of direct oral anticoagulants (DOACs) in obese patients (body mass index [BMI] ≥ 30 kg/m2) due to concerns regarding their efficacy and safety in this demographic. Aim: This review aimed to consolidate current evidence on the efficacy and safety of DOACs versus warfarin in obese patients with non-valvular atrial fibrillation (AF) or venous thromboembolism (VTE). The primary efficacy outcome assessed a composite of all-cause mortality, stroke, systemic embolism (SE), and myocardial infarction (MI). Methods: A systematic search was conducted in MEDLINE, SCOPUS, and Cochrane databases from inception to December 28, 2023. Data were synthesized using random-effects meta-analysis. Results: A total of 35 studies involving 434,320 participants were analyzed. DOAC use was associated with a significant reduction in the risk of the composite outcome (RR = 0.80, 95% CI [0.65, 0.98], I2 = 95%), hemorrhagic stroke (RR = 0.58, 95% CI [0.38, 0.88], I2 = 92%), major bleeding (RR = 0.76, 95% CI [0.63, 0.92], I2 = 94%), gastrointestinal bleeding (RR = 0.59, 95% CI [0.49, 0.72], I2 = 88%), and intracranial bleeding (RR = 0.45, 95% CI [0.34, 0.60], I2 = 44%) compared to warfarin. A non-significant benefit of DOACs was observed for all-cause mortality, MI, the composite of stroke or SE, ischemic stroke, SE, VTE, and minor bleeding compared to warfarin. Subgroup analysis indicated no significant effect modification based on the indication for anticoagulation or study design. Conclusions: DOACs demonstrated a favorable efficacy and safety profile in obese individuals compared to warfarin.

Safety and efficacy of direct oral anticoagulants in comparison to warfarin in obese patients with atrial fibrillation: A systematic review and meta-analysis

Background and Aim

Obesity affects nearly 650 million adults worldwide, and the prevalence is steadily rising. This condition has significant adverse effects on cardiovascular health, increasing the risk of hypertension, coronary artery disease, heart failure, and atrial fibrillation (AF). While anticoagulation for obese patients with AF is a well-established therapy for the prevention of thromboembolism, the safety and efficacy of different anticoagulants in this specific population are not well explored. This meta-analysis aimed to compare direct oral anticoagulants (DOAC) to vitamin K antagonists in obese populations with AF.

Methods

The PRISMA guidelines were followed for this meta-analysis, registered in PROSPERO (CRD42023392711). PubMed, PubMed Central, Embase, Cochrane Library, and Scopus databases were searched for relevant articles from inception through January 2023. Two independent authors screened titles and abstracts, followed by a full-text review in Covidence. Data were extracted in Microsoft Excel and analyzed using RevMan v5.4 using odds ratio as an effect measure.

Results

Two thousand two hundred fifty-nine studies were identified from the database search, and 18 were included in the analysis. There were statistically significant reductions in the odds of ischemic and hemorrhagic stroke in the DOAC group compared with the VKA group (OR 0.70, CI 0.66-0.75) and (OR 0.47, CI 0.35-0.62), respectively. In addition, the DOAC group exhibited lower odds of systemic embolism (OR 0.67, CI 0.54-0.83), major bleeding (OR 0.62, CI 0.54-0.72), and composite outcome (OR 0.72, CI 0.63-0.81).

Conclusion

Based on the findings from this meta-analysis, DOACs demonstrate superior safety and efficacy in obese patients with AF compared with VKAs. These results may have significant implications for guiding anticoagulation strategies in this patient population.

Effectiveness and safety of non-vitamin K antagonist oral anticoagulant in the treatment of patients with morbid obesity or high body weight with venous thromboembolism: A meta-analysis

BACKGROUND

Venous thromboembolism (VTE) poses a significant health risk to patients with morbid obesity or high body weight. Non-vitamin K antagonist oral anticoagulants (NOACs) are emerging treatments, but their effectiveness and safety compared with vitamin K antagonists (VKAs) in this population are yet to be thoroughly studied.

METHODS

We conducted a systematic review and meta-analysis, adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Four electronic databases were searched for relevant studies comparing the efficacy and safety of NOACs and VKAs in treating patients with VTE with a body mass index > 40 kg/m2 or body weight > 120 kg. Eligible studies were scored for quality using the Newcastle-Ottawa Scale.

RESULTS

Thirteen studies were included. The meta-analysis results showed that compared to VKAs, NOACs significantly decreased the risk of VTE occurrence (odds ratio = 0.72, 95% CI: 0.57-0.91, I2 = 0%, P < .001) and were associated with a lower risk of bleeding (odds ratio = 0.74, 95% CI: 0.58-0.95, I2 = 0%, P < .05). Subgroup analysis showed that in the cancer patient subgroup, both risks of VTE occurrence and bleeding were lower in the NOAC group than in the VKA group. In patients without cancer, the risk of VTE was significantly lower in the NOAC group.

CONCLUSION

NOACs appear to be more effective and safer than VKAs in patients with morbid obesity or a high body weight with VTE. However, further large-scale randomized controlled trials are required to confirm these findings.

DOAC compared with warfarin for VTE in patients with obesity: a retrospective cohort study conducted through the VENUS network

The effectiveness and safety of direct oral anticoagulants (DOAC) compared with warfarin remains uncertain in obese patients. We assessed the comparative effectiveness and safety of DOACs with warfarin for the treatment of VTE among obese patients. This multi-center retrospective cohort study included adults with a BMI ≥ 35 kg/m2 or weight ≥ 120 kg prescribed either DOAC (apixaban, dabigatran, edoxaban, rivaroxaban) or warfarin for a VTE diagnosis. The primary outcome was the 12-month rate of recurrent VTE. The secondary outcome was the 12-month rate of major bleeding. Among 5626 patients, 67% were prescribed warfarin and 33% were prescribed a DOAC. The 12-month VTE recurrence rate was 3.6% (67/1823) for patients treated with DOAC compared with 3.8% (143/3664) for patients treated with warfarin [odds ratio for recurrent VTE on warfarin versus DOAC (OR) (95% CI).07 (0.80, 1.45)]. The 12-month major bleeding rate was 0.5% (10/1868) for patients on DOAC versus 2.4% (89/3758) on warfarin [OR 4.25 (2.19, 8.22)]. Similar proportions of recurrent VTE occurred across BMI thresholds on DOAC and warfarin: for BMI ≥ 35 kg/m2 (N = 5412), 3.6% versus 3.8%, respectively [OR 1.08 (0.80, 1.46)]; for BMI ≥ 40 kg/m2 (N = 2321), 4.4% versus 3.5%, respectively [OR 0.80 (0.51, 1.26)]; and for BMI ≥ 50 kg/m2 (N = 560), 3.1% versus 3.7%, respectively [OR 1.18 (0.39, 3.56)]. Similar proportions of recurrent VTE occurred in patients with obesity treated for VTE with DOACs and warfarin. DOACs were associated with lower major bleeding compared to warfarin in patients with obesity and VTE.

Dilemmas Related to Direct-Acting Oral Anticoagulant Administration in Patients With Extreme Obesity

OBJECTIVE

The objective of the study was to discuss the controversies surrounding the use and dosing of direct-acting oral anticoagulants (DOACs) in obese patients recognizing the limitations of the existing evidence base that preclude strong recommendations.

DATA SOURCES

A literature search of MEDLINE was performed (2020 to end August 2022) subsequent to recent guidelines using the following search terms: direct acting anticoagulants, obesity, rivaroxaban, apixaban, edoxaban, dabigatran, dabigatran etexilate, and clinical practice guidelines.

STUDY SELECTION AND DATA ABSTRACTION

English-language studies and those conducted in adults were selected.

DATA SYNTHESIS

The available randomized studies evaluating DOACs had relatively small numbers of patients with more extreme forms of obesity (body mass index [BMI] > 40 kg/m²) and none of the larger studies had a specific focus on dosing DOACs in obese patients. Recent guidelines by the International Society on Thrombosis and Haemostasis (ISTH) have specific recommendations for dosing DOACs in obesity. There are pharmacokinetic/pharmacodynamic and observational studies published before and after the ISTH guidelines with a focus on DOAC dosing in obese patients that generally support the recommendations in the guidelines, but most involved small numbers of patients usually with BMIs <45 kg/m².

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

This review discusses DOAC dosing in obesity with important considerations for clinicians related to DOAC choice and dosing.

CONCLUSIONS

Dosing alterations of DOACs do not appear to be necessary when used for either prophylaxis or treatment in patients with BMIs up to approximately 45 to 50 kg/m², but research is needed for BMIs >50 kg/m².

Effectiveness and Safety of Dabigatran in Atrial Fibrillation Patients with Severe Obesity: a Real-World Retrospective Cohort Study

BACKGROUND

Direct oral anticoagulants such as dabigatran are the preferred anticoagulant in treating atrial fibrillation (AF) patients due to their effectiveness and safety. Whether this applies to severely obese patients needs to be determined.

OBJECTIVE

To compare the effectiveness and safety of dabigatran with warfarin among AF patients with severe obesity.

DESIGN

Retrospective cohort study.

PARTICIPANTS

AF patients with a BMI >40kg/m2 or a weight >120kg receiving dabigatran or warfarin between 10/01/2010 and 12/31/2019 in a large integrated health system and followed through 08/01/2020.

INTERVENTIONS

Not applicable.

MAIN MEASURES

Primary effectiveness outcome was composite thromboembolism including transient ischemic attack, ischemic stroke, or systemic embolism. Primary safety outcome was composite bleeding including gastrointestinal bleeding, intracranial bleeding, or other bleeding. Secondary outcomes included the individual outcomes and all-cause mortality. Propensity score matching (PSM) was performed to create a 1:1 matched cohort and Cox proportional hazards model was used to estimate the hazard ratio (HR) of each outcome for dabigatran users compared to warfarin users.

KEY RESULTS

A total of 6848 patients receiving either dabigatran or warfarin were identified. In a 1:1 matched cohort, dabigatran users had a HR of 0.71 (95% confidence interval (CI): 0.56-0.91) for composite thromboembolism, a HR of 1.24 (95%CI: 1.07-1.42) for composite bleeding, and a HR of 0.57 (95% CI: 0.45-0.71) for all-cause mortality when compared to warfarin users.

CONCLUSIONS

Among AF patients with a BMI >40kg/m2 or a weight >120kg in a real-world clinical setting, dabigatran was effective in reducing the risk of thromboembolism and mortality but was associated with an increased risk of bleeding when compared to warfarin. Dabigatran may be a reasonable option for AF patients with severe obesity.

Anticoagulation and BMI: effect of high body weight on the safety and efficacy of direct oral anticoagulants

Obesity is an epidemic with rising prevalence, and obese patients are predisposed to comorbid conditions that increase risk for thromboembolic events. It is critical to identify safe and effective anticoagulation therapy for use in this population. Direct oral anticoagulants (DOACs) are a preferred option for anticoagulation in patients of normal weight due to many benefits and equivalent safety and efficacy to their vitamin K antagonist counterparts. However, the safety and efficacy of DOACs in obese patients is not well understood. This review describes recent studies on the pharmacokinetics, safety and efficacy, and clinical outcomes of the DOACs apixaban, rivaroxaban, edoxaban and dabigatran in obese patient populations. DOACs may be a beneficial alternative to vitamin K antagonist therapy in obese patient populations.

Safety and efficacy of Apixaban and Rivaroxaban in obese patients with acute thrombosis/embolism

INTRODUCTION

Direct oral anticoagulants (DOACs) have significant advantages over vitamin K antagonists in the treatment of venous thromboembolism and as prophylaxis against recurrence. However, there is inadequate data to support the safety and efficacy of DOACs in the morbidly obese, and warfarin treatment is currently recommended by the International Society of Hemostasis and Thrombosis for this population.

MATERIALS AND METHODS

We performed a retrospective review of outcomes in 499 patients with BMI ≥ 40 kg/m² admitted from January 2013 to January 2020 with acute venous thromboembolism (VTE) and treated with either rivaroxaban (n=296) or apixaban (n=203).

RESULTS

There were 38 (7.6%) bleeding and clotting events within 60 days of the initiation of DOACs, of which 35 (7.0%) were bleeding events and 3 (0.6%) were clotting events. Patients treated with rivaroxaban had more bleeding episodes (23, 7.8% vs. 12, 5.9%) and higher mortality (21, 7.1% vs. 13, 6.4%) compared with those treated with apixaban; however, these differences were not statistically significant (p=.427 and p=.764, respectively). Most of the bleeding occurred in the genitourinary and gastrointestinal tracts.

CONCLUSIONS

Our study indicates that apixaban and rivaroxaban are not associated with an increase in VTE recurrence in the morbidly obese; however, bleeding rates were slightly higher in the rivaroxaban group compared to the apixaban group.

Apixaban Use in Obese Patients: A Review of the Pharmacokinetic, Interventional, and Observational Study Data

Abstract

Relatively little is known about the influence of extreme body weight on the pharmacokinetics (PK), pharmacodynamics (PD), efficacy, and safety of drugs used in many disease states. While direct oral anticoagulants (DOACs) have an advantage over warfarin in that they do not require routine drug monitoring, some may regard this convenience as less compelling in obese patients. Some consensus guidelines discourage using DOACs in patients weighing > 120 kg or with a body mass index > 35–40 kg/m², given a sparsity of available data in this population and the concern that fixed dosing in obese patients might lead to decreased drug exposure and lower efficacy. Per the prescribing information, apixaban does not require dose adjustment in patients weighing above a certain threshold (e.g., ≥ 120 kg). Data from healthy volunteers and patients with nonvalvular atrial fibrillation (NVAF) or venous thromboembolism (VTE) have shown that increased body weight has a modest effect on apixaban’s PK. However, the paucity of exposure data in individuals > 120 kg and the lack of guideline consensus on DOAC use in obese patients continue to raise concerns about potential decreased drug exposure at extreme weight. This article is the first to comprehensively review the available PK data in obese individuals without NVAF or VTE, and PK, PD, efficacy, effectiveness, and safety data for apixaban in obese patients with either NVAF or VTE, including subgroup analyses across randomized controlled trials and observational (real-world) studies. These data suggest that obesity does not substantially influence the efficacy, effectiveness, or safety of apixaban in these patients.

Trial Registration ARISTOTLE: NCT00412984; AVERROES: NCT00496769; AMPLIFY: NCT00643201; AMPLIFY-EXT: NCT00633893; ADVANCE-1: NCT00371683; ADVANCE-2: NCT00452530; ADVANCE-3: NCT00423319

Video abstract

Evaluation of Apixaban safety and effectiveness in morbidly obese patients with atrial fibrillation: a retrospective cohort study

Background

The benefit of apixaban to reduce stroke risk in morbidly obese patients with nonvalvular atrial fibrillation (AF) is still undetermined. The International Society of Thrombosis and Hemostasis recommends avoiding the use of direct oral anticoagulants (DOAC)s in morbidly obese patients (body mass index > 40 or weight > 120 kg) because of limited clinical data. This exploratory study aims to evaluate the effectiveness and safety of using apixaban in morbidly obese (body mass index (BMI) ≥ 40) patients with AF.

Methods

An exploratory retrospective cohort study was conducted at a single-center, including adult patients with non-valvular AF using apixaban between 01/01/2016 and 31/12/2019. Patients were excluded if they were known to have liver cirrhosis Child-Pugh C, mechanical valve, serum creatinine > 1.5 mg/dL, follow up < 3 months, or using apixaban with a dose of ≤5 or > 10 mg/day. Included patients were categorized into two groups based on their BMI (BMI<40 Vs. BMI ≥ 40). The primary outcome was all thrombotic events, while the secondary outcomes were major and minor bleeding after apixaban initiation. Propensity score (PS) matching was used (1:1 ratio) based on the patient’s age, gender, and HAS-BLED score.

Results

A total of 722 patients were eligible; 254 patients were included after propensity score matching based on the selected criteria. The prevalence of all thrombotic events was similar between the two groups in the first year of apixaban initiation (OR (95%CI): 0.58 (0.13, 2.5), p-value = 0.46). In addition, the odds of developing major and minor bleeding were not statistically significant between the two groups (OR (95%CI): 0.39 (0.07, 2.03), p-value = 0.26 and OR (95%CI): 1.27 (0.56, 2.84), p-value = 0.40), respectively).

Conclusion

This exploratory study showed similar effectiveness and safety of apixaban use in both morbid and non-morbid obese patients with non-valvular AF. However, a larger randomized controlled trial with a longer follow-up period needs to confirm our findings.

Comparative Effectiveness and Safety of Direct Oral Anticoagulants vs Warfarin Among Obese Patients With Atrial Fibrillation

Background

Obese patients are underrepresented in clinical trials assessing the comparative effectiveness and safety of use of direct oral anticoagulants vs use in atrial fibrillation (AF) patients.

Methods

Using data from Quebec provincial administrative databases, for the years2010-2017, we created a retrospective cohort of patients with inpatient or outpatient coding for AF and obesity who were newly prescribed an oral anticoagulant. The primary safety outcome was a composite of intracranial, gastrointestinal, and major bleeding from other sites, and the primary effectiveness outcome was a composite of ischemic stroke, systemic embolism, acute myocardial infarction, and death in the first year after oral anticoagulant initiation. Treatment groups were compared using inverse-probability-of-treatment-weighting Cox proportional-hazards models.

Results

A total of 2263 patients were included, of whom 1253, 403, and 539 filled a warfarin, standard-dose rivaroxaban, and standard-dose apixaban prescription, respectively. Standard-dose rivaroxaban was associated with a similar composite safety (hazard ratio [HR] 0.91; 95% confidence interval [CI] 0.44-1.91) and composite effectiveness risk (HR 1.42; 95% CI 0.99-2.04) compared to warfarin, whereas standard-dose apixaban was associated with a lower composite safety (HR 0.40; 95% CI 0.16-0.98) and similar composite effectiveness risk (HR 0.96; 95% CI 0.67-1.39).

Conclusion

Use of direct oral anticoagulants in obese AF patients was associated with a similar effectiveness and safety profile to that of warfarin use.

Inter- and intra-individual concentrations of direct oral anticoagulants: The KIDOAC study

BACKGROUND

Direct oral anticoagulants (DOACs) do not require concentration monitoring. However, whether DOAC concentrations are stable and their variation between and within patients is not well studied.

METHODS

Patients on vitamin K antagonists (VKA) who switched to rivaroxaban, apixaban, or dabigatran were included between 2018 and 2020. Blood was drawn at DOAC trough and peak concentrations at week 0, 2, and 8. Plasma drug concentrations were determined by anti-factor Xa concentrations (rivaroxaban, apixaban) or diluted thrombin time (dabigatran). Inter- and intra-individual variability was assessed by calculating the coefficient of variation (CV). Linear regression models were employed to evaluate associations between DOAC trough concentrations and previous VKA dosage, creatinine clearance, and body mass index (BMI).

RESULTS

One hundred fifty-two patients were included, of whom 96 (63%) were male and with a mean age of 73.9 ± 8.4 years. For the inter-individual variability, the CV ranged between 48% and 81% for trough values and between 25% and 69% for peak values among patients using the recommended DOAC dose. Intra-individual variability was substantially lower, as here the CV ranged between 18% and 33% for trough values and between 15% and 29% for peak values among patients using the recommended DOAC dose. Previous VKA dosage and creatinine clearance were inversely associated with DOAC trough concentrations. No association was found between BMI and DOAC trough concentrations.

CONCLUSION

Inter-individual variability of DOAC concentrations was higher than intra-individual variability. Lower previous VKA dosage and creatinine clearance were associated with higher DOAC trough concentrations. These findings support further study into an optimal target range, in which the risks of both bleeding and thrombosis are minimal.

Oral Anticoagulant Use in Morbid Obesity and Post Bariatric Surgery: A Review

Bariatric surgery has emerged as a therapy for obesity and the associated comorbidities. Obesity has been shown to be a risk factor for atrial fibrillation as well as venous thromboembolism, both of which are conditions that warrant anticoagulation. There is significant underrepresentation of the morbidly obese population in prospective trials that evaluated direct oral anticoagulants and vitamin K antagonists in atrial fibrillation and venous thromboembolism. We aim to review all the available data that assessed these oral anticoagulants in the morbidly obese population (body mass index >40 kg/m² and weight >120 kg) and in the post-bariatric surgery population. Our findings suggest that direct oral anticoagulants may be safe and effective for anticoagulation in morbidly obese patients for both atrial fibrillation and venous thromboembolism. However, warfarin is the preferred agent in the post-bariatric surgery population, given the limited number of studies on direct oral anticoagulants in this population. Further adequately powered randomized control trials are needed to confirm the safety and efficacy of these oral anticoagulants in the morbidly obese and post-bariatric surgery population.

Anti-Xa Levels in Morbidly Obese Patients Using Apixaban or Rivaroxaban, Before and After Bariatric Surgery

BACKGROUND

Despite limited evidence about the efficacy and safety of anticoagulation in patients post bariatric surgery, both vitamin K antagonists (VKA) and direct-acting oral anticoagulants (DOACs) are commonly prescribed.

AIM

To evaluate plasma anti-Xa levels of DOACs in morbidly obese (MO) patients before and after a Roux-en-Y gastric bypass (RYGB) procedure.

PATIENTS AND METHODS

Retrospective, cross-sectional, and longitudinal study of anti-Xa activity of apixaban or rivaroxaban in MO patients (N = 41).

RESULTS

Preoperative analysis of plasma anti-Xa levels were within the normal range in patients using apixaban (n = 29; body mass index [BMI] 44.5 ± 5.1 kg/m²) as well as those using rivaroxaban (n = 12; BMI 42.6 ± 5.9 kg/m²). Postoperative anti-Xa levels of apixaban were all within the therapeutic range, whereas anti-Xa levels of rivaroxaban were subtherapeutic in nine out of 14 (64%) patients. Perioperative longitudinal follow-up in patients using apixaban (n = 18) showed no significant change in anti-Xa levels after RYGB.

CONCLUSION

Plasma anti-Xa levels of apixaban in MO patients remained within the therapeutic range up to a body weight of 144 kg. In patients using rivaroxaban, no statistically significant relation between anti-Xa levels and bodyweight was found. After RYGB, plasma anti-Xa levels of apixaban were unaffected, whereas plasma anti-Xa levels of rivaroxaban tended to become subtherapeutic.

Effectiveness and Safety of Direct Oral Anticoagulants in Patients with Nonvalvular Atrial Fibrillation and Weighing ≥ 120 Kilograms versus 60-120 Kilograms

BACKGROUND

Direct oral anticoagulants (DOACs) have become favorable choices for anticoagulation due to their fixed-dose schedule, limited need for monitoring, and non-inferiority or superiority to warfarin. DOACs are currently not recommended in patients with a body weight ≥ 120 kg or body mass index ≥ 40 kg/m² due to limited data regarding safety and efficacy.

OBJECTIVE

The aim of this study was to compare the safety and efficacy of DOACs in patients with nonvalvular atrial fibrillation (NVAF) and weighing ≥ 120 kg with those weighing < 120 kg.

METHODS

A single-center, retrospective study was conducted in patients weighing ≥ 120 kg who received either apixaban, dabigatran, or rivaroxaban for stroke risk reduction in NVAF, and matched to patients who weighed < 120 kg. The primary outcome was the incidence of stroke, deep vein thrombosis, pulmonary embolism, or myocardial infarction, while the safety outcome was the incidence of major or clinically relevant non-major bleeding based on the International Society on Thrombosis and Haemostasis (ISTH) definitions.

RESULTS

A total of 318 patients weighing ≥ 120 kg with NVAF and meeting the inclusion criteria were evaluated and matched with 318 patients weighing < 120 kg. The primary outcome occurred in 2.5% of patients in the ≥ 120 kg group and in 3.1% of patients in the < 120 kg group (p = 0.632). The safety outcome occurred in 5.3% and 6.6% of patients in these respective groups (p = 0.503).

CONCLUSION

Apixaban, dabigatran, or rivaroxaban may be well-tolerated and effective anticoagulant options in patients with NVAF weighing ≥ 120 kg.

Oral anticoagulant use in patients with morbid obesity: A systematic review and meta-analysis

OBJECTIVES

Obesity is associated with increased risks of atrial fibrillation (AF) and venous thromboembolism (VTE) for which anticoagulation is commonly used. However, data on the efficacy and safety of oral anticoagulants in patients with morbid obesity are limited.

METHODS

We conducted a systematic review and meta-analysis to evaluate the efficacy and safety of direct oral anticoagulants (DOACs) or vitamin K antagonists (VKAs) for AF or VTE in patients with morbid obesity.

RESULTS

We included 3 randomized controlled trials (5 studies) and 18 observational studies in adult patients with a body weight ≥ 120 kg, body mass index (BMI) ≥ 40 kg/m2 or classified as morbid obesity who received DOACs or VKAs for AF or VTE (N=77,687). The primary efficacy outcome was stroke/systemic embolism or recurrent VTE, and the primary safety outcome was major bleeding. DOACs were associated with a pooled incidence rate of stroke/systemic embolism of 1.16 per 100 person-years, compared to 1.18 with VKAs. The incidence of recurrent VTE on DOACs was 3.83 per 100 person-years, compared to 6.81 on VKAs. In both VTE and AF populations, DOACs were associated with lower risks of major bleeding compared to VKAs. However, all observational studies had moderate to serious risks of bias.

CONCLUSIONS

Patients with morbid obesity on DOACs had similar risks of stroke/systemic embolism, lower rates of recurrent VTE and major bleeding events compared to those on VKAs. However, the certainty of evidence was low given that studies were mostly observational with high risk of confounding.

Direct Oral Anticoagulants Versus Warfarin in Morbidly Obese Patients With Nonvalvular Atrial Fibrillation: A Systematic Review and Meta-analysis

BACKGROUND

Direct oral anticoagulants (DOACs) have been increasingly preferred over warfarin; however, The International Society of Thrombosis and Hemostasis recommended avoiding the use of DOACs in morbidly obese patients (body mass index >40 or weight >120 kg) because of limited clinical data.

STUDY QUESTION

Are DOACs effective and safe in morbidly obese patients with nonvalvular atrial fibrillation (NVAF).

DATA SOURCES

We performed a comprehensive search for published studies indexed in PubMed/MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials that evaluated the efficacy and safety of DOACs in morbidly obese patients with NVAF.

STUDY DESIGN

Information on patient characteristics, comorbidities, primary anticoagulation indications, pharmacologic treatment, and outcomes were collected. The primary outcome of interest was stroke or systemic embolism (SSE) rate. The secondary outcome was major bleeding (MB).

RESULTS

A total of 10 studies including, 89,494 morbidly obese patients with NVAF on oral anticoagulation therapy (45,427 on DOACs vs. 44,067 on warfarin) were included in the final analysis. The SSE rate was significantly lower in DOACs group compared with warfarin group [odds ratio: 0.71; 95% confidence interval (CI): 0.62-0.81; P < 0.0001; I2 = 0%]. MB rate was also significantly lower in DOACs group compared with the warfarin group (odds ratio: 0.60; 95% CI: 0.46-0.78; P < 0.0001; I2 = 86%). On subgroup analysis, SSE and MB event rates were significantly lower in rivaroxaban and apixaban than warfarin; however, dabigatran showed noninferiority to warfarin in SSE rate but superiority in the safety outcome.

CONCLUSIONS

Our meta-analysis demonstrated that DOACs are effective and safe with statistical superiority when compared with warfarin in morbidly obese patients. Large-scale randomized clinical trials are needed to further evaluate the efficacy and safety of DOACs in this cohort of patients.

Real-world effectiveness and safety of rivaroxaban versus warfarin among non-valvular atrial fibrillation patients with obesity in a US population

OBJECTIVES

Current evidence indicates that the pharmacokinetic profile of rivaroxaban is not significantly impacted by body weight. However, real-world data are needed to better assess the potential clinical benefits and risks associated with rivaroxaban in non-valvular atrial fibrillation (NVAF) patients with obesity. Thus, our objectives were to assess the real-world effectiveness and safety of rivaroxaban versus warfarin among NVAF patients with obesity in the US nationally representative commercially-insured population.

METHODS

Health insurance claims data from the IQVIA PharMetrics Plus database (January 2010-September 2019) were used to identify NVAF patients with obesity (based on diagnosis codes) initiated on rivaroxaban or warfarin. Inverse probability of treatment weighting (IPTW) was used to adjust for imbalances between groups. Study outcomes of interest were evaluated up to 36 months post-treatment initiation and included the composite of stroke or systemic embolism (stroke/SE) and major bleeding. Outcomes were compared using Cox proportional hazards regression models with hazard ratios (HR) and 95% confidence intervals (CIs).

RESULTS

A total of 10,555 patients were initiated on rivaroxaban and 5080 patients on warfarin. Following IPTW, the risk of stroke/SE was 26% lower among patients prescribed rivaroxaban relative to warfarin (HR: 0.74, 95% CI: 0.60, 0.91, p = .004) at 36 months. Rivaroxaban-initiated patients had a risk of major bleeding similar to that of warfarin-initiated patients (HR: 0.85, 95% CI: 0.71, 1.02, p = .085).

CONCLUSIONS

These results suggest that rivaroxaban is an effective and safe treatment option among NVAF patients with obesity in a commercially-insured US population.

Direct Oral Anticoagulants in the Treatment of Venous Thromboembolism: Use in Patients with Advanced Renal Impairment, Obesity, or Other Weight-Related Special Populations

There are currently more than 7 million patients taking a direct oral anticoagulant (DOAC), with more new prescriptions per year than warfarin. Despite impressive efficacy and safety data for the treatment of venous thromboembolism, patients with obesity or advanced renal impairment represented a small portion of the patients enrolled in the phase 3 clinical trials. Therefore, to evaluate the potential use of DOACs in these special populations, clinicians need to have an understanding of the pharmacokinetics and pharmacodynamics of these agents in these settings. Since data from randomized controlled trials are limited, data from observational trials are helpful in gaining comfort with the use of DOACs in these special populations. Selecting the appropriate dose for each agent is imperative in achieving optimal patient outcomes. We provide an extensive review of the pharmacokinetics, pharmacodynamics, phase 3 clinical trials, and observational studies on the use of DOACs in patients with advanced renal impairment, obesity, or other weight-related special populations to provide clinicians with a comprehensive understanding of the data for optimal drug and dose selection.

Non-Vitamin K Antagonist Oral Anticoagulants (NOACs) Versus Warfarin in Patients with Atrial Fibrillation and (Morbid) Obesity or Low Body Weight: a Systematic Review and Meta-Analysis

PURPOSE

Oral anticoagulants are crucial for preventing systemic thromboembolism in atrial fibrillation (AF), with guidelines preferring non-vitamin K antagonist oral anticoagulants (NOACs) over vitamin K antagonists (VKAs) in the general AF population. However, as NOACs are administered in fixed doses, concerns of unintentional underdosing in morbidly obese patients and unintentional overdosing in underweight patients have emerged. Therefore, a critical appraisal of the benefit-risk profile of NOACs in AF patients across the body weight spectrum is needed.

METHODS AND RESULTS

After searching Medline, this systematic review discusses the impact of body weight on the risk-benefit profile of NOACs versus VKAs. The meta-analysis demonstrated that NOAC use in obese and class III obese AF patients (body mass index (BMI) ≥ 30 and ≥ 40 kg/m², respectively) was associated with significantly lower stroke/systemic embolism (stroke/SE) risks (RR 0.82, 95%CI [0.71-0.96] and RR 0.75, 95%CI [0.64-0.87], respectively), similar to lower major bleeding risks (RR 0.83, 95%CI [0.69-1.00] and RR 0.74, 95%CI [0.57-0.95], respectively) and similar mortality risks (RR 0.92, 95%CI [0.73-1.15] and RR 1.17, 95%CI [0.83-1.64], respectively) compared to VKAs. In AF patients ≤ 60 kg, significantly lower stroke/SE (RR 0.63, 95%CI [0.56-0.71]) and major bleeding risks (RR 0.71, 95%CI [0.62-0.80]), but similar mortality risks (RR 0.68, 95%CI [0.42-1.10]), were observed for NOAC- versus VKA-treated patients.

CONCLUSION

The benefit-risk profile of NOACs seems preserved in (morbidly) obese AF patients and patients with low body weight. However, more data are needed on underweight AF patients (BMI < 18.5 kg/m²) and on differences between NOACs in these patients.