Direct Oral Anticoagulants in Obesity: An Updated Literature Review

Efficacy, safety, and feasibility of Apixaban for postoperative venous thromboembolism prophylaxis following open gynecologic cancer surgery at a comprehensive cancer center

OBJECTIVES

To evaluate safety, efficacy, and feasibility of apixaban for postoperative venous thromboembolism (VTE) prophylaxis following open gynecologic cancer surgery at a comprehensive cancer center.

METHODS

This retrospective, cohort study included patients with gynecologic cancer who underwent open surgery between 3/2021 and 3/2023 and received 28-day postoperative VTE prophylaxis. Patients on therapeutic anticoagulation preoperatively were excluded. Predictors of 90- and 30-day VTE and 30-day bleeding events were determined using multivariable logistic regression, adjusting for known confounders.

RESULTS

452 patients were included in the cohort: 348 received apixaban and 104 received enoxaparin. Those who received enoxaparin were more likely to be American Society of Anesthesiologists class III/IV (compared to I/II) (p = 0.033), current or former smokers (p = 0.012) and have a higher BMI (p < 0.001), Charlson Comorbidity Index (p = 0.005), and age (p = 0.046). 30-day VTE rate was significantly lower in the apixaban group (0.6%) compared to the enoxaparin group (6.2%) (adjusted OR 0.13, 95% CI 0.03-0.56; p = 0.006). 90-day VTE rate was 2.7% and 6.2% in the apixaban and enoxaparin groups, respectively (adjusted OR 0.85, 95% CI 0.38-1.92; p = 0.704). Major bleeding complications (2.4% vs. 2.0%) and minor bleeding complications (0.9% vs. 3.0%) were similar in the apixaban and enoxaparin groups, respectively, on multivariate analyses. The median patient out of pocket cost was $10 (IQR 0.0-40.0) for apixaban and $20 (IQR 3.7-67.7) for enoxaparin (p = 0.001).

CONCLUSIONS

Our findings along with previously published data suggest that apixaban should be considered the standard of care for VTE prophylaxis in patients undergoing open surgery for gynecologic malignancies.

Recent Progress on Green New Phase Extraction and Preparation of Polyphenols in Edible Oil

With the proposal of replacing toxic solvents with non-toxic solvents in the concept of green chemistry, the development and utilization of new green extraction techniques have become a research hotspot. Phenolic compounds in edible oils have good antioxidant activity, but due to their low content and complex matrix, it is difficult to achieve a high extraction rate in a green and efficient way. This paper reviews the current research status of novel extraction materials in solid-phase extraction, including carbon nanotubes, graphene and metal-organic frameworks, as well as the application of green chemical materials in liquid-phase extraction, including deep eutectic solvents, ionic liquids, supercritical fluids and supramolecular solvents. The aim is to provide a more specific reference for realizing the green and efficient extraction of polyphenolic compounds from edible oils, as well as another possibility for the future research trend of green extraction technology.

Go Big or Go Home: Obesity and Total Joint Arthroplasty

Obesity is highly prevalent, and it is expected to grow considerably in the United States. The association between obesity and an increased risk of complications following total joint arthroplasty (TJA) is widely accepted. Many believe that patients with body mass index (BMI) >40 have complications rates that may outweigh the benefits of surgery and should consider delaying it. However, the current literature on obesity and outcomes following TJA is observational, very heterogeneous, and full of confounding variables. BMI in isolation has several flaws and recent literature suggests shifting from an exclusively BMI <40 cutoff to considering 5 to 10% preoperative weight loss. BMI cutoffs to TJA may also restrict access to care to our most vulnerable, marginalized populations. Moreover, only roughly 20% of patients instructed to lose weight for surgery are successful and the practice of demanding mandatory weight loss needs to be reconsidered until convincing evidence exists that supports risk reduction as a result of preoperative weight loss. Obese patients can benefit greatly from this life-changing procedure. When addressing the potential difficulties and by optimizing preoperative assessment and intraoperative management, the surgery can be conducted safely. A multidisciplinary patient-centered approach with patient engagement, shared decision-making, and informed consent is recommended.

Lifestyle changes in atrial fibrillation management and intervention

Atrial fibrillation (AF) is one of the most common arrhythmias in adults, and its continued rise in the United States is complicated by the increased incidence and prevalence of several AF risk factors, such as obesity, physical inactivity, hypertension, obstructive sleep apnea, diabetes mellitus, coronary artery disease, and alcohol, tobacco, or caffeine use. Lifestyle and risk factor modification has been proposed as an additional pillar of AF therapy, added to rhythm control, rate control, and anticoagulation, to reduce AF burden and risk. Although emerging evidence largely supports the integration of lifestyle and risk factor management in clinical practice, randomized clinical trials investigating the long-term sustainability and reproducibility of these benefits remain sparse. The purpose of this review is to discuss potentially reversible risk factors on AF, share evidence for the impact on AF by modification of these risk factors, and then provide an overview of the effects of reversing or managing these risk factors on the success of various AF management strategies, such as antithrombotic, rate control, and rhythm control therapies.

Direct oral anticoagulant drugs for the management of venous thromboembolism

ABSTRACT

Direct oral anticoagulants (DOACs) are effective for both prevention and treatment of venous thromboembolism (VTE) and have favorable safety in comparison with warfarin. Although drug-drug interactions with DOACs are not as frequent as with warfarin, certain drugs can interfere with DOAC metabolism, affect DOAC efficacy, and potentially cause adverse reactions when used in combination with DOACs. The NP must determine which agent is most beneficial for the individual patient with VTE based on a number of factors. A knowledge of periprocedural management of DOACs will assist the NP in providing a smooth transition for patients undergoing minor and major procedures and surgeries.

Direct oral anticoagulants and warfarin safety in rural patients with obesity

BACKGROUND

Direct oral anticoagulants (DOACs) are often used in patients with atrial fibrillation or flutter instead of warfarin and although supporting evidence is limited, available studies suggest this may be an acceptable route of care. Our study assessed the question: are DOACs as effective and safe as warfarin in patients with atrial fibrillation and class III obesity specifically in a rural population?

METHODS

A retrospective analysis was conducted by examining the first 6-12 months of therapy with a DOAC (apixaban or rivaroxaban) or warfarin in patients with weight >120kg or class III obesity. Events of interest, thrombosis and bleeding, were documented for analysis. The risk and odds of events of interest for both groups were calculated and compared.

RESULTS

Characteristics of both arms were similar (DOAC n=42; warfarin n=43). A lack of thrombosis events limited efficacy analysis. A total of 22 bleeds occurred with 8 in patients prescribed a DOAC (7 minor; 1 major) and 14 in those prescribed warfarin (12 minor; 2 major). Weight in kg (p<0.001), BMI (p=0.013) and HAS-BLED score (p=0.035) were predictive of a first bleeding event in patients prescribed warfarin. The odds ratio for any type of bleed on DOAC vs warfarin was 0.55 (0.180-1.681; 95% CI).

CONCLUSIONS

In patients with atrial fibrillation and class III obesity, regarding safety, DOACs appear to be non-inferior to warfarin during the first six to 12 months of therapy in our rural population - consistent with other analyses; however, the lack of thrombosis events limited the efficacy analysis.

Fibrinogen, Coagulation, and Ageing

The World Health Organization estimates that the world's population over 60 years of age will nearly double in the next 30 years. This change imposes increasing demands on health and social services with increased disease burden in older people, hereafter defined as people aged 60 years or more. An older population will have a greater incidence of cardiovascular disease partly due to higher levels of blood fibrinogen, increased levels of some coagulation factors, and increased platelet activity. These factors lead to a hypercoagulable state which can alter haemostasis, causing an imbalance in appropriate coagulation, which plays a crucial role in the development of cardiovascular diseases. These changes in haemostasis are not only affected by age but also by gender and the effects of hormones, or lack thereof in menopause for older females, ethnicity, other comorbidities, medication interactions, and overall health as we age. Another confounding factor is how we measure fibrinogen and coagulation through laboratory and point-of-care testing and how our decision-making on disease and treatment (including anticoagulation) is managed. It is known throughout life that in normal healthy individuals the levels of fibrinogen and coagulation factors change, however, reference intervals to guide diagnosis and management are based on only two life stages, paediatric, and adult ranges. There are no specific diagnostic guidelines based on reference intervals for an older population. How ageing relates to alterations in haemostasis and the impact of the disease will be discussed in this chapter. Along with the effect of anticoagulation, laboratory testing of fibrinogen and coagulation, future directions, and implications will be presented.

Coronavirus Disease 2019-Related Extensive Thrombosis in a Patient Receiving Therapeutic Anticoagulation With Dabigatran

Introduction and Objective: Coronavirus disease 2019 (COVID-19) is associated with respiratory failure and a hypercoagulable state. Studies have shown the use of oral anticoagulants, specifically dabigatran, can significantly decrease mortality from COVID-19. Dabigatran is an oral direct thrombin inhibitor commonly used for nonvalvular atrial fibrillation and for the treatment or prevention of venous thromboembolism. The association of COVID-19-related extensive thrombosis while receiving full therapeutic anticoagulation with dabigatran has not been well-established in current literature. Case Report: We present a 73-year-old male patient with a history of persistent atrial fibrillation anticoagulated with dabigatran presenting with an active COVID-19 infection admitted to the intensive care unit. On hospital day 7, he developed extensive arterial and venous thromboembolisms. To our knowledge, this is the first published case of COVID-19-related extensive thrombosis while receiving full therapeutic anticoagulation with dabigatran. Discussion: Guidelines recommend prophylactic or therapeutic-dose anticoagulation with unfractionated heparin or low-molecular weight heparin for all patients if no contraindications exist; however, recommendations for the use of therapeutic oral anticoagulants have not been well established. Further studies are warranted to establish appropriate use of oral anticoagulants in the setting of COVID-19. Conclusion: Evidence from this report suggests clinicians should closely monitor patients at risk for hypercoagulability regardless of the anticoagulation therapy the patient may be receiving. Additionally, evidence from this case suggests a possible inferiority in the anticoagulation ability of dabigatran in patients with active COVID-19.

Obesity and the Risk of Venous Thromboembolism after Major Lower Limb Orthopaedic Surgery: A Literature Review

The risk of venous thromboembolism following total joint arthroplasty is significantly greater than those of other types of elective orthopaedic procedures. This risk is increased in obesity due to the associated prothrombotic physiological and hematological changes that predispose to embolic events. The prevalence of obesity is increasing in the aging population, which contributes to a further increase in the risk of postoperative thrombosis in the older patients. There is a lack of clear evidence regarding dosing information for thromboprophylaxis medications in patients with obesity. As a result, the currently available thromboprophylaxis guidelines do not provide specific recommendations for this group. Suboptimal dosing regimens for these medications can place these patients at a risk of bleeding or clotting complications postsurgery. Hence any increase in dosage may require intensive surveillance for the residual anticoagulant effects and careful balancing of risks and benefits on an individual basis. Our review discusses the basis for increased thrombotic risk in obesity, the evidence supporting dosage recommendations, and the implications of the current guidelines for pharmacological thromboprophylaxis in patients with obesity undergoing lower limb arthroplasty.

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.

Morbidly Obese Patients Undergoing Primary Total Joint Arthroplasty May Experience Higher Rates of Venous Thromboembolism When Prescribed Direct Oral Anticoagulants vs Aspirin

BACKGROUND

Morbidly obese (body mass index [BMI] >40 kg/m²) patients undergoing total joint arthroplasty (TJA) are at high risk for postoperative venous thromboembolism (VTE); however, there is debate surrounding the optimal pharmacologic agent for prevention of VTE after TJA in this patient subset. Current guidelines recommend against direct-acting oral anticoagulants (DOACs) in patients of BMI >40 kg/m² due to low quality evidence justifying their use. We evaluated whether patients of BMI >40 kg/m² undergoing primary unilateral TJA would have increased risk of postoperative VTE if prescribed DOACs compared to non-DOAC agents such as aspirin.

METHODS

This retrospective study analyzed 897 patients of BMI >40 kg/m² undergoing primary unilateral TJA. Demographic and comorbidity-related variables were collected. The association between postoperative VTE and prophylactic pharmacologic agent prescribed was evaluated by multivariate logistic regression.

RESULTS

After controlling for comorbidities, we found that the sole use of DOACs, specifically apixaban, for VTE prophylaxis was associated with an increased risk of developing VTE compared to prophylaxis with aspirin alone in patients of BMI >40 kg/m² (odds ratio 2.962, P = .016). Regardless of VTE prophylactic agent, patients with BMI >40 kg/m² undergoing TKA had at least 4.5-fold increased odds of developing VTE compared to patients undergoing THA (OR 4.830, P = .019).

CONCLUSION

In our retrospective study of a large sample size of patients with BMI >40 kg/m², we found that the use of DOACs, specifically apixaban, for VTE prophylaxis following TJA was associated with increased odds of a VTE complication compared to the use of aspirin alone.

Effectiveness and Safety of Rivaroxaban versus Warfarin Among Nonvalvular Atrial Fibrillation Patients with Obesity and Polypharmacy

Background

Current evidence suggests that rivaroxaban may be well tolerated and effective in patients with nonvalvular atrial fibrillation (NVAF) and obesity; however, there is limited evidence on the impact of polypharmacy in this population. This study evaluated real-world clinical outcomes with rivaroxaban versus warfarin in patients with NVAF and obesity according to the number of concurrent medications.

Methods

This retrospective cohort study identified patients with one or more pharmacy claim for rivaroxaban or warfarin from two large claims databases. Patients were required to have an atrial fibrillation diagnosis, body mass index ≥ 30 kg/m² and the presence of polypharmacy (1–4, 5–9, or ≥ 10 concurrent medications). Outcomes of stroke, systemic embolism, and major bleeding were compared between the rivaroxaban and warfarin cohorts after propensity score matching (PSM).

Results

A total of 95,875 patients were identified with one or more claim for either rivaroxaban or warfarin. After PSM, patient characteristics were balanced between cohorts (n = 21,547 in each cohort). The overall composite risk of stroke and systemic embolism was significantly lower in the rivaroxaban cohort compared with the warfarin cohort (hazard ratio [HR] 0.77, 95% confidence interval [CI] 0.70–0.84; p < 0.001). The risks of ischemic stroke, hemorrhagic stroke, and systemic embolism separately were also significantly reduced with rivaroxaban. Major bleeding risk was similar between cohorts (HR 0.93, 95% CI 0.81–1.06; p = 0.2842), and results were consistent across the three polypharmacy groups.

Conclusions

In this real-world study of NVAF patients with obesity, rivaroxaban was associated with lower risks of stroke and systemic embolism and similar risk of major bleeding versus warfarin across polypharmacy categories.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40256-021-00520-7.

Direct oral anticoagulation and severe obesity - One size fits all?

Oral anticoagulation is obligatory in patients with atrial fibrillation (AF) to prevent thromboembolic stroke. Direct direct oral anticoagulants (DOAC) exhibit improved safety over Vitamin K antagonists, but any interference in haemostasis can impact on bleeding. Optimal anticoagulation remains challenging particularly in patients with co-morbidities. International Society of Thrombosis and Haemostasis (ISTH) guidelines recommend avoiding DOAC in patients with severe obesity, and systematic data on individual DOAC drug concentrations, clinical efficacy and safety in relation to body weight are lacking. A new study now provides reassurance that DOAC are safe and effective in a real-world cohort of morbidly obese patients, going some way to fill the knowledge gap pertaining to optimal management of concomitant obesity and AF.

Healthcare Resource Utilization and Costs of Rivaroxaban Versus Warfarin Among Nonvalvular Atrial Fibrillation Patients with Obesity and Diabetes

INTRODUCTION

Nonvalvular atrial fibrillation (NVAF) is associated with a substantial economic burden, particularly in patients with comorbid conditions. This study compared healthcare resource utilization (HRU) and costs of rivaroxaban and warfarin in patients with NVAF, obesity, and diabetes.

METHODS

A de-identified healthcare claims database was used to identify adult patients newly initiating rivaroxaban or warfarin and having at least one medical claim with a diagnosis of AF, obesity determined by validated algorithm, and at least one claim with a diagnosis of diabetes or for antidiabetic medication from December 2011 to March 2020. Propensity score matching was used to balance the treatment cohorts on the basis of demographics and baseline characteristics. All-cause and NVAF-related HRU rates and costs were compared between treatments using rate ratios, and mean cost differences were calculated on a per patient per year (PPPY) basis.

RESULTS

A total of 9999 matched pairs of patients with NVAF, obesity, and diabetes were identified in the rivaroxaban and warfarin cohorts. Rate ratios of all-cause HRU were significantly reduced with rivaroxaban versus warfarin in all healthcare settings evaluated, except emergency room visits. The greatest impact was on physician office visits followed by hospital outpatient and inpatient visits. NVAF-related HRU was significantly lower for rivaroxaban versus warfarin in all care settings. Consistent with these findings, the length of hospital stay was significantly reduced by approximately 4 days among all patients for both all-cause and NVAF-related hospitalizations in the rivaroxaban cohort compared with the warfarin cohort. Rivaroxaban was associated with reductions in all-cause total healthcare costs by more than $5000 PPPY and NVAF-related medical costs by approximately $1100 PPPY.

CONCLUSION

In comparison with warfarin, rivaroxaban reduced HRU and costs, particularly hospital inpatient and outpatient visits and physician office visits, in patients with NVAF and comorbidities of obesity and diabetes.

Effectiveness and safety of rivaroxaban versus warfarin among nonvalvular atrial fibrillation patients with obesity and diabetes

AIMS

To compare clinical outcomes of rivaroxaban and warfarin in patients with nonvalvular atrial fibrillation (NVAF) and concurrent obesity and diabetes.

METHODS

Patients aged ≥18 years were identified from a healthcare claims database with the following criteria: newly initiating rivaroxaban or warfarin, ≥1 medical claim with a diagnosis of AF, obesity determined by validated machine learning algorithm, and ≥1 claim with a diagnosis of diabetes or for antidiabetic medication. Treatment cohorts were matched using propensity scores and were compared for stroke/systemic embolism (SE) and major bleeding using Cox proportional hazards models.

RESULTS

A total of 9999 matched pairs of NVAF patients with obesity and diabetes who initiated treatment with rivaroxaban or warfarin were included. The composite risk of stroke/SE was significantly lower in the rivaroxaban cohort compared with the warfarin cohort (HR 0.82; 95% CI 0.74-0.90). Risks of ischemic and hemorrhagic strokes were also significantly reduced with rivaroxaban versus warfarin, but not SE. Major bleeding risk was similar between treatment cohorts (HR 0.92; 95% CI 0.78-1.09).

CONCLUSIONS

In NVAF patients with comorbidities of obesity and diabetes, rivaroxaban was associated with lower risks of stroke/SE and similar risk of major bleeding versus warfarin.

Effectiveness of Direct Oral Anticoagulants in Obese Adults With Atrial Fibrillation: A Systematic Review of Systematic Reviews and Meta-Analysis

Background: Atrial Fibrillation (AF) is the most common sustained cardiac arrhythmia. Obesity is an independent risk factor for AF. Anticoagulants have been strongly recommended by all international guidelines to prevent stroke. However, altered pathophysiology in obese adults may influence anticoagulant pharmacology. Direct oral anticoagulants (DOACs) in the context of obesity and AF have been examined in recent systematic reviews. Despite the similarities in included studies, their results and conclusions do not agree.

Methods and Results: The protocol for this review was registered with PROSPERO (CRD42020181510). Seven key electronic databases were searched using search terms such as “atrial fibrillation,” “obese,^*” “overweight,” “novel oral anticoagulant,” “direct oral anticoagulant,” “DOAC,” “NOAC,” “apixaban,” dabigatran,” “rivaroxaban,” and “edoxaban” to locate published and unpublished studies. Only systematic reviews with meta-analyses that examined the effect of DOACs in overweight or obese adults with AF, published in the English language, were included. A total of 9,547 articles were initially retrieved. After removing the duplicates, title and abstract review and full-text review, five articles were included in the systematic review. From these only RCTs were included in the meta-analyses. There was disagreement within the published systematic reviews on DOACs in obesity. The results from our meta-analysis did not show any significant difference between all body mass index (BMI) groups for all outcomes at both 12 months and for the entire trial duration. Non-significant differences were seen among the different types of DOACs.

Conclusion: There was no difference between the BMI classes in any of the outcomes assessed. This may be due to the limited number of people in the trial that were in the obese class, especially obese class III. There is a need for large prospective trials to confirm which DOACs are safe and efficacious in the obese class III adults and at which dose.

Use of direct oral anticoagulants for acute pulmonary embolisms in obesity: a propensity-matched, multicentre case-control study

Direct oral anticoagulants (DOACs) are widely used as first-line treatment for pulmonary embolism (PE) in patients without contraindications [1]; however, limited data exists on the efficacy and safety in obesity. The most recent International Society of Thrombosis and Haemostasis guidelines recommend avoiding DOACs in individuals with body mass index (BMI) >40 kg·m⁻² or body weight >120 kg, due to lack of robust clinical efficacy data. Obtaining serum drug levels for therapeutic monitoring in this population has been suggested; however, testing of DOAC levels is neither widely available nor well validated in real-world clinical settings [2]. Given the ongoing uncertainty regarding the clinical outcomes with DOACs in treating acute PE in obese patients, this study aimed to evaluate the efficacy and safety of DOACs compared to warfarin in this population.

Assessment of efficacy and safety of DOACs in treatment of pulmonary embolisms in obese patients provides reassurance that treatment with DOACs carries similar rates of recurrent VTE and bleeding complications to warfarinhttps://bit.ly/2VdrSXX

Impact of Weight on Clinical Outcomes of Edoxaban Therapy in Atrial Fibrillation Patients Included in the ETNA-AF-Europe Registry

BACKGROUND

Extremes of body weight may alter exposure to non-vitamin K antagonist oral anticoagulants and thereby impact clinical outcomes. This ETNA-AF-Europe sub-analysis assessed 1-year outcomes in routine care patients with atrial fibrillation across a range of body weight groups treated with edoxaban.

METHODS

ETNA-AF-Europe is a multinational, multicentre, observational study conducted in 825 sites in 10 European countries. Overall, 1310, 5565, 4346 and 1446 enrolled patients were categorised into ≤60 kg, >60-≤80 kg (reference weight group), >80-≤100 kg and >100 kg groups.

RESULTS

Patients weighing ≤60 kg were older, more frail and had a higher CHA2DS2-VASc score vs. the other weight groups. The rates of stroke/systemic embolism, major bleeding and ICH were low at 1 year (0.82, 1.05 and 0.24%/year), with no significant differences among weight groups. The annualised event rates of all-cause death were 3.50%/year in the overall population. After adjustment for eGFR and CHA2DS2-VASc score, the risk of all-cause death was significantly higher in extreme weight groups vs. the reference group.

CONCLUSIONS

Low rates of stroke and bleeding were reported with edoxaban, independent of weight. The risk of all-cause death was higher in extremes of weight vs. the reference group after adjustment for important risk modifiers, thus no obesity paradox was observed.

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.

Efficacy, Safety, and Exposure of Apixaban in Patients with High Body Weight or Obesity and Venous Thromboembolism: Insights from AMPLIFY

Introduction

As a result of limited clinical data, guidelines do not recommend the use of non-vitamin K antagonist oral anticoagulants in patients who weigh > 120 kg or have a body mass index (BMI) > 40 kg/m².

Methods

This post hoc analysis of the AMPLIFY trial evaluated the efficacy (venous thromboembolism [VTE]/VTE-related death), safety (major and composite of major and clinically relevant non-major [CRNM] bleeding), and exposure of apixaban compared with enoxaparin followed by warfarin for the treatment of VTE by body weight (≤ 60, > 60 to < 100, ≥ 100 to < 120, ≥ 120 kg) and BMI (≤ 25, > 25 to 30, > 30 to 35, > 35 to 40, > 40 kg/m²).

Results

Among the AMPLIFY safety population, 5384 and 5359 patients had recorded body weight (range 28.9 to 222.0 kg; ≥ 120 kg, n = 290) and BMI (range 12.5–71.8 kg/m²; > 40 kg/m², n = 263), respectively. The rates of recurrent VTE/VTE-related death for apixaban versus enoxaparin/warfarin were similar across body weight subgroups: relative risks (RR; 95% confidence intervals [CI]) were 0.63 (0.23, 1.72), 0.99 (0.65, 1.50), 0.77 (0.34, 1.72), and 0.20 (0.02, 1.72) for the ≤ 60, > 60 to < 100, ≥ 100 to < 120, and ≥ 120 kg groups, respectively (P_interaction = 0.44). The rates of major bleeding were lower with apixaban versus enoxaparin/warfarin; RRs (95% CI) were 0.15 (0.02, 1.15), 0.41 (0.21, 0.77), not estimable, and 0.34 (0.04, 3.22), respectively (P_interaction = not estimable). The rates of major/CRNM bleeding were significantly lower for apixaban versus enoxaparin/warfarin; RRs (95% CI) were 0.46 (0.24, 0.89), 0.49 (0.38, 0.63), 0.30 (0.16, 0.58), and 0.28 (0.12, 0.66), respectively (P_interaction = 0.36). Similar trends were seen in the BMI subgroups. There was a modest, not clinically meaningful, decrease (< 30%) in the median predicted exposure with increasing body weight (n = 281).

Conclusions

The findings of this post hoc analysis support the use of apixaban in patients with body weight ≥ 120 kg or BMI > 40 kg/m².

Trial Registration Number

NCT00643201

Graphic Abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-021-01716-8.

Atrial thrombi in elective patients considered for atrial fibrillation rhythm control: Risk factors and prognostic value

The prognostic value of atrial thrombi (AT) among elective patients with atrial fibrillation (AF) referred for a rhythm control strategy is unclear. In this study, clinical variables were correlated with the presence of AT and long term survival among 205 patients submitted to transesophageal echocardiography before elective AF cardioversion or ablation. Atrial thrombi were present in 7.8% of cases and were significantly associated with reduced survival. Obesity was the only independent clinical predictor of AT [OR 4.27 (1.15-15.79), p = 0.03]. In patients with AF, AT appear to be associated with adverse outcomes, possibly indicating more advanced atrial cardiomyopathy.

Risk of recurrent stroke for Asian stroke patients treated with non-vitamin K antagonist oral anticoagulant and warfarin

Aim:

The aim of this study was to establish whether non-vitamin K antagonist oral anticoagulants (NOACs) are superior to warfarin in preventing stroke recurrence for atrial fibrillation (AF) patients with an ischemic or hemorrhagic stroke at the baseline.

Methods:

From 1 January 2009 to 31 December 2017, stroke patients with AF treated with oral anticoagulants in the National Health Insurance Research Database in Taiwan were enrolled. The study was retrospective cohort design. Outcome measures were ischemic and hemorrhagic stroke recurrence. The Cox proportional hazard model was used to obtain the hazard ratio (HR).

Results:

In total, 39,840 stroke patients with AF treated with NOAC and 42,583 treated with warfarin were identified. NOACs were superior to warfarin in preventing all recurrent stroke [adjusted HR: 0.67, 95% confidence interval (CI), 0.63–0.71, p < 0.001]. Results for the ischemic stroke population were the same as that for all types for stroke (adjusted HR: 0.66, 95% CI, 0.62–0.70, p < 0.001). For the hemorrhagic stroke population, NOACs were equivalent to warfarin in preventing ischemic stroke (adjusted HR: 1.11, 95% CI, 0.86–0.43, p < 0.001), but NOACs were superior to warfarin in preventing hemorrhagic stroke (adjusted HR: 0.64, 95% CI, 0.55–0.74, p < 0.001).

Conclusions:

NOACs were generally superior to warfarin in terms of efficacy and safety in previous stroke patients. The robustness of our findings was verified and should add new information to current recommendations for Asian stroke patients in selecting NOACs.