How I treat obese patients with oral anticoagulants

Higher Pulmonary Embolism Risk in Morbidly Obese Patients on Aspirin Monotherapy after Total Knee Arthroplasty: A Claims Database Analysis

BACKGROUND

Aspirin is the most common drug used for venous thromboembolism (VTE) prophylaxis after total knee arthroplasty (TKA). Morbid obesity is a potential risk factor for VTE, prompting some to use stronger anticoagulants. However, there are no established guidelines for VTE prevention in obese or morbidly obese patients undergoing primary TKA.

METHODS

Using a national administrative claims database, patients who underwent primary TKA were divided into the following three cohorts based on body mass index (BMI): < 30, 30 to 39.9, or ≥ 40. Each patient had a prescription claim for aspirin, but no other prophylaxis agents within 3 days after the index procedure. We assessed deep vein thrombosis (DVT) and pulmonary embolism (PE) incidence at 90 and 180 days postoperatively. Secondary outcomes included wound dehiscence; hematoma; periprosthetic joint infection; and debridement, antibiotics, and implant retention or explantation procedures. We included 20,097 patients, of whom 4,277 (21%), 10,663 (53%), and 5,157 (26%) had a BMI < 30, 30 to 39.9, and ≥ 40, respectively.

RESULTS

In the multivariable analysis, there was no difference in the incidence of DVT or PE within 90 or 180 days after surgery for the BMI 30 to 39.9 compared to the BMI < 30 cohort. However, the incidence of PE within 90 days after surgery was higher in the BMI ≥ 40 cohort (odds ratio: 2.74), an effect that disappeared by 180 days. There was a higher adjusted odds of debridement, antibiotics, and implant retention procedures in the BMI ≥ 40 compared to the BMI < 30 cohort; otherwise, the incidence of secondary outcomes did not differ by BMI.

CONCLUSIONS

When aspirin was used as a standardized monotherapy for VTE prophylaxis following primary TKA, there was an increased 90-day incidence of PE in morbidly obese patients but no difference in DVT or PE incidence in obese patients.

Retrospective study of clinical settings, indications and consequences of measurement of direct oral anticoagulant plasma levels in Northern Tasmania, Australia

BACKGROUND

Routine monitoring of direct oral anticoagulant (DOAC) levels is not recommended but may be useful in certain clinical situations. There is a knowledge gap regarding the clinical use of DOAC levels in Australian hospitals.

AIMS

To evaluate the clinical settings, indications and changes to anticoagulant management associated with DOAC levels in a tertiary hospital in Northern Tasmania, Australia.

METHODS

Patients with one or more DOAC levels (dabigatran, rivaroxaban or apixaban) requested between January 2017 and December 2022 were identified. Retrospective chart review was performed to evaluate the clinical settings, indications, adequacy of request information and changes to clinical management associated with the measurement of DOAC levels.

RESULTS

One hundred and twenty-nine DOAC measurements (54 rivaroxaban, 66 apixaban and nine dabigatran) were performed in 98 patients between January 2017 and December 2022. Annual requests for DOAC levels increased significantly between 2017 and 2019 and remained stable between 2020 and 2021 but declined in 2022. Overall, the most common indication for a DOAC level was renal impairment, followed by bleeding and recurrent thrombosis. Approximately 25% of requests were for acute bleeding with a reversal/haemostatic agent given in 45% of patients, while 10% were prior to urgent surgery. Measurement of DOAC levels was associated with a change in management in 50% of cases. 10% of requests did not specify anticoagulant history.

CONCLUSION

Trends in requests for DOAC levels have changed over time. Clinician education regarding the importance of providing specific anticoagulant history is essential. Future prospective studies investigating the clinical utility of DOAC levels in different clinical settings are needed.

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.

Apixaban thromboprophylaxis in ambulatory patients with cancer and obesity: Insights from the AVERT trial

BACKGROUND

The use of direct oral anticoagulants (DOACs) in obese patients is uncertain. It is unclear if body mass index (BMI) affects the safety and efficacy of DOACs for the primary prevention of venous thromboembolism (VTE) in high-risk ambulatory patients with cancer. We sought to determine the outcomes associated with the use of apixaban for the primary prevention of cancer-associated VTE according to BMI.

METHODS

The randomized, double-blinded, placebo-controlled AVERT trial evaluated apixaban thromboprophylaxis in intermediate-to-high risk ambulatory cancer patients receiving chemotherapy. For this post-hoc analysis, the primary efficacy and safety outcomes were objectively confirmed VTE and clinically relevant bleeding (major and clinically relevant non-major bleeding), respectively. Obesity was defined as BMI ≥30 kg/m².

RESULTS

Among 574 patients randomized, 217 (37.8 %) patients had BMI ≥30 kg/m². Obese patients were overall younger, more likely to be female, had higher creatinine clearance and hemoglobin, lower platelet count, and better ECOG performance status. Compared to placebo, apixaban thromboprophylaxis was associated with reduced VTE in both obese (hazard ratio [HR] 0.26; 95 % confidence interval [CI], 0.14-0.46; p < 0.0001) and non-obese (HR 0.54; 95%CI, 0.29-1.00; p = 0.049) patients. The HR for clinically relevant bleeding (apixaban vs. placebo) was numerically higher in obese (2.09; 95%CI, 0.96-4.51; p = 0.062) than non-obese subjects (1.23; 95%CI, 0.71-2.13; p = 0.46), but overall in line with the risks observed in the general trial population.

CONCLUSIONS

In the AVERT trial enrolling ambulatory cancer patients receiving chemotherapy, we found no substantial differences in the efficacy or safety of apixaban thromboprophylaxis across obese and non-obese subjects.

Operative Techniques to Reduce Hip and Knee Arthroplasty Complications in Morbidly Obese Patients

Obesity, defined as a body mass index (BMI) >30, is associated with an increased likelihood of osteoarthritis and need for total joint arthroplasty (TJA). Unfortunately, the morbidly obese population has a higher risk of postoperative complications. For some surgeons, patient selection criteria for TJA includes BMI<40. The associated risks are recognized by The American Association of Hip And Knee Surgeons, and many surgeons follow these guidelines. Importantly, as obese patients have been demonstrated to have equal or greater gains in functional outcomes and quality of life metrics, it is important for obese patients to have access to TJA. Through a comprehensive literature review and structured interviews with leading surgeons in the field, we provide guidance for orthopedic surgeons treating patients with BMI>40 to minimize risks, including tailored preoperative, intraoperative, and postoperative considerations.

Prescribing direct-acting oral anticoagulants - mind the evidence gap

Direct-acting oral anticoagulants (DOACs) are licensed for the prevention of thromboembolism in non-valvular atrial fibrillation amongst other indications. Prescribers use information derived from the summary of product characteristics which is based on the key trials supporting the DOAC's market authorisation. However, prescribers may not be aware of the limitations within these trials regarding underrepresentation of patient populations commonly encountered in clinical practice and how this may adversely impact them. This review highlights the gaps in the licensing evidence using 4 clinical vignettes that explore prescribing challenges in older adults, female patients, patients with obesity and patients from non-Europid ethnic backgrounds.

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.

Real life behaviour of direct oral anticoagulants in patients with nonvalvular atrial fibrillation and morbid obesity

Atrial fibrillation (AF) is the most prevalent arrhythmia worldwide and the main cause of anticoagulation, being direct oral anticoagulants (DOAC) increasingly used in this context. On the other hand, obesity is a known risk thromboembolic factor. In the clinical trials that led to the approval of DOAC for ischemic stroke prevention, patients with morbid obesity were underrepresented. The International Society of Thrombosis and Haemostasis suggests not using these drugs in morbid obese patients. Thus, the primary objectives of this study were to analyse the rates of mortality, thrombotic and haemorrhagic events in patients with morbid obesity. As secondary objectives, factors statistically associated with these events were analysed. Methods: multicentre retrospective study that included patients diagnosed with AF on treatment with DOAC from January 2013 to December 2016. The subgroup of patients with morbid obesity (BMI > 40 and / or weight > 120 kg) was analysed. Mean follow-up was 1.7 years. Results: Amongst 2,492 patients included in the study, 135 patients had morbid obesity (mean age was 71 ± 11 years). The mean scores of the CHA2DS2-VASc and HAS-BLED risk scales were 3.7 ± 1.6 and 2.2 ± 0.9, respectively. Neither differences were found regarding mortality (5.2 vs 6/100 patient-years, p = 0.662), ischemic stroke (0.8 vs 1.9/100 patient-years, p = 0.261) and major bleeding rates (3 vs 3.1/100 patient-years, p = 0.983) between morbidly obese population and general population. Nor was there an association found between the degree of obesity and any of the events studied. Conclusion: DOAC are safe and effective in morbidly obese patients.

Venous thromboembolism

Venous thromboembolism, comprising both deep vein thrombosis and pulmonary embolism, is a chronic illness that affects nearly 10 million people every year worldwide. Strong provoking risk factors for venous thromboembolism include major surgery and active cancer, but most events are unprovoked. Diagnosis requires a sequential work-up that combines assessment of clinical pretest probability for venous thromboembolism using a clinical score (eg, Wells score), D-dimer testing, and imaging. Venous thromboembolism can be considered excluded in patients with both a non-high clinical pretest probability and normal D-dimer concentrations. When required, ultrasonography should be done for a suspected deep vein thrombosis and CT or ventilation-perfusion scintigraphy for a suspected pulmonary embolism. Direct oral anticoagulants (DOACs) are the first-line treatment for almost all patients with venous thromboembolism (including those with cancer). After completing 3-6 months of initial treatment, anticoagulation can be discontinued in patients with venous thromboembolism provoked by a major transient risk factor. Patients whose long-term risk of recurrent venous thromboembolism outweighs the long-term risk of major bleeding, such as those with active cancer or men with unprovoked venous thromboembolism, should receive indefinite anticoagulant treatment. Pharmacological venous thromboembolism prophylaxis is generally warranted in patients undergoing major orthopaedic or cancer surgery. Ongoing research is focused on improving diagnostic strategies for suspected deep vein thrombosis, comparing different DOACs, developing safer anticoagulants, and further individualising approaches for the prevention and management of venous thromboembolism.

Direct oral anticoagulant use in special populations

PURPOSE OF REVIEW

The pivotal phase III trials demonstrating efficacy and safety of direct oral anticoagulants (DOACs) in the treatment of venous thromboembolism (VTE) or nonvalvular atrial fibrillation (NVAF) excluded patients with important and common comorbidities, including obesity, advanced chronic kidney disease, cirrhosis, cancer and antiphospholipid antibody syndrome. Despite the lack of large prospective randomized control trials in these patient populations, the use of DOACs has led to a wealth of efficacy and safety data within these groups.

RECENT FINDINGS

Retrospective studies, meta-analyses, national databases and pharmacokinetic data have shed light on the efficacy and safety of DOACs in these patient populations. Although DOACs should be avoided in those with high-risk triple positive antiphospholipid antibody syndrome, advanced cirrhosis, advanced kidney disease and intact gastrointestinal cancers, and used with caution in genitourinary cancers, their use extends beyond the inclusion criteria of the initial randomized control trials.

SUMMARY

DOACs have revolutionized anticoagulant management and have become the cornerstone for VTE treatment and stroke prevention in NVAF. The decision to use DOACs must be individualized. Patient preference, underlying comorbidities and informed consent must always be considered when selecting the most appropriate anticoagulant.

Efficacy and Safety of Direct Oral Anticoagulants in Venous Thromboembolism Compared to Traditional Anticoagulants in Morbidly Obese Patients: A Systematic Review and Meta-Analysis

Background

Randomized clinical trials comparing the efficacy and safety of direct oral anticoagulants (DOAC) with vitamin K antagonist (VKA) or low molecular weight heparin (LMWH) for the treatment of venous thromboembolism (VTE) generally exclude patients who are morbidly obese (body mass index ≥ 40 kg/m² or weight ≥ 120 kg). Recently, smaller studies have compared DOACs with warfarin or low molecular weight heparin (LMWH) in morbidly obese patients with VTE. We aim to systematically review and do a meta-analysis of the studies that directly compared DOACs with VKAs or LMWH in morbidly obese patients.

Methods

Studies comparing DOAC with warfarin or LMWH in patients with acute VTE were identified through electronic literature searches of MEDLINE, EMBASE, Scopus, clinicaltrials.gov, and the Cochrane Library up to March 2020. The primary efficacy outcome was recurrent VTE and the primary safety outcome was major bleeding as defined by the International Society on Thrombosis and Haemostasis (ISTH) guidelines. Study-specific odds ratios (OR) were calculated and combined using a random-effects model meta-analysis.

Result

Five studies were identified. Recurrent VTE occurred in 95 of 3207 (2.96%) patients in the DOAC group and 81 of 3181 (2.54%) patients in the VKA and LMWH group (OR: 1.17; 95% CI 0.87 to 1.59, p=.30). Major bleeding occurred in 63 of 3316 (1.89%) patients in the DOAC group, and 83 of 3259(2.54%) patients in the VKA or LMWH group (OR: 0.74; 95% CI: 0.53 to 1.03, p=.08). Sensitivity analysis comparing factor Xa inhibitors apixaban and rivaroxaban to warfarin also yielded consistent findings.

Conclusion

DOACs showed similar efficacy and safety in the prevention of recurrent VTE risk and major bleeding events in morbidly obese patients when compared to warfarin/LMWH. Our study underscores the need for further modifications of therapy to reduce the high VTE recurrence rate irrespective of whether the patient is on a DOAC or VKA. This might be possible through a very large multi-institutional randomized clinical trial.

Treatment of venous thromboembolism in cancer patients: The dark side of the moon

Venous thromboembolism (VTE) is a common complication in patients with cancer. The risk of emergent VTE is four- to seven-fold higher in cancer patients compared to non-cancer patients. Although the therapeutic armamentarium for cancer-associated VTE has been recently implemented, anticoagulant treatment remains challenging because of the increased risk of recurrent VTE and bleeding. Several international societies and expert panels released clinical practice guidelines on VTE treatment which are mostly focused on the general cancer population. Nevertheless, recommendations for the management of VTE in patients with peculiar clinical presentations are inconsistent and remain elusive due to the lack of pertinent evidence. The challenging clinical scenarios include, among others, patients with thrombocytopenia, renal impairment, gastrointestinal cancer, primary or metastatic brain cancer, distal thrombosis of the lower extremities, catheter-related VTE, splanchnic thrombosis, incidental VTE, extreme body weight, recurrent VTE during treatment, as well as the optimal duration of anticoagulant treatment in patients with active disease who have received 3 to 6 months of anticoagulation. Herein, we present a critical overview on VTE management in these challenging clinical settings, discuss potential approaches, and include some calls to action for future clinical research.

Direct oral anticoagulant therapy in patients with morbid obesity after intermediate- or high-risk pulmonary emboli

There is little reported on the efficacy and safety of direct oral anticoagulants (DOACs) in morbid obesity after venous thromboembolism (VTE). In this observational study, patients were followed up after intermediate- or high-risk pulmonary embolism (PE) at the University of Rochester Pulmonary Hypertension Clinic 2-4 months after the initial event. All patients had echocardiography and V/Q imaging regardless of symptoms. Outcomes of interest were the rates of recurrent VTE, thrombus resolution and development of chronic thromboembolic pulmonary hypertension (CTEPH) in patients with morbid obesity treated with a DOAC compared to treatment with vitamin K antagonists and to non-morbidly obese patients after PE. Using the electronic medical record, recurrent events were assessed up to 12 months after the event. 107 patients (body mass index (BMI)>40 kg·m^-2, n=32; BMI 30-39.9 kg·m^-2, n=39; BMI<30 kg·m^-2, n=36) attended follow-up appointments after treatment for PE. A DOAC was used in 70 patients (BMI>40 kg·m^-2, n=19; BMI 30-39.9 kg·m^-2, n=27; BMI<30 kg·m^-2, n=24). There were no recurrent events within the first 12 months of initial diagnosis based on symptoms and imaging in any patient. There was no difference in rate of residual unmatched perfusion defect with DOACs or conventional anticoagulation (49% versus 49%). This finding remained in the subset of morbidly obese patients (47% versus 50%). For the overall cohort, there was no difference in the rate of CTEPH development based on anticoagulation with a DOAC (5% versus 8% with warfarin). There were no major bleeding complications with a DOAC. DOAC therapy appears to be effective and safe in morbid obesity even after intermediate- or high-risk PE. ​.

Characteristics, anticoagulation, and outcomes of portal vein thrombosis after intra-abdominal surgery

BACKGROUND

Intra-abdominal surgery is a cause of portal vein thrombosis; however, postsurgical portal vein thrombosis has not been extensively described.

METHODS

This is a retrospective study of 107 patients with postsurgical portal vein thrombosis followed for a median 25 months (interquartile range 11-51). Outcomes were complete radiographic resolution of portal vein thrombosis and development of clinical portal hypertension.

RESULTS

Surgeries associated with portal vein thrombosis included colectomy (n = 42), bariatric surgery (n = 25), and splenectomy (n = 11). Presentations were nonspecific, typically characterized by abdominal pain. Sixty-three patients (59%) achieved complete radiographic resolution. On univariable analysis, provoking surgery, occlusivity of portal vein thrombosis, and anticoagulant used were associated with complete radiographic resolution. Colectomy was associated with a complete radiographic resolution rate of 30/42 (71%), bariatric 10/25 (40%), splenectomy 2/11 (18%), and other 21/29 (72%), (log rank P = .0033). Nonocclusive thrombus was associated with a complete radiographic resolution rate of 44/62 (71%), occlusive thrombus 19/45 (42%), (log rank P = .0101). Direct oral anticoagulants were associated with a complete radiographic resolution rate of 27/35 (77%), enoxaparin 20/29 (69%), warfarin 14/31 (45%), and no anticoagulant 2/12 (17%), (log rank P = .0002). On multivariable analysis, only anticoagulant choice was significantly associated with complete radiographic resolution. Using direct oral anticoagulants as reference, no anticoagulant yielded an adjusted hazard ratio of 0.10 for complete radiographic resolution (95% confidence interval 0.023-0.44), warfarin 0.40 (95% confidence interval 0.20-0.78), and enoxaparin 0.64 (95% confidence interval 0.49-1.60). Failure to achieve complete radiographic resolution was associated with greater risk of future clinical portal hypertension. Twenty-three patients (21%) went on to develop clinical portal hypertension; 20 who failed to achieve complete radiographic resolution (45%), and only 3 who achieved complete radiographic resolution (5%), (log rank P < .0001).

CONCLUSION

The natural history of postsurgical portal vein thrombosis is variable and influenced by type of surgery, degree of occlusion, and, most notably, type of anticoagulant used. Failure to recanalize the portal vein carries considerable risk of future clinical portal hypertension.

Weight-adjusted tinzaparin for venous thromboembolism prophylaxis in bariatric surgery patients weighing 160 kg or more

INTRODUCTION

Bariatric surgery patients experience an increased risk of venous thromboembolism (VTE), however, the optimal dose of low-molecular-weight heparin for VTE prophylaxis remains uncertain. Currently, St. Joseph's Healthcare Hamilton utilizes a weight-adjusted tinzaparin dosage (50 to 75 units/kg rounded to nearest pre-filled syringe) for postoperative VTE prophylaxis.

OBJECTIVES

This study analyzed the safety of weight-adjusted tinzaparin for VTE prophylaxis in bariatric surgery patients weighing ≥160 kg.

METHODS

This was a retrospective study involving patients weighing ≥160 kg that underwent bariatric surgery from September 2015 to September 2019. Patients received a single dose of weight-adjusted subcutaneous unfractionated heparin (UFH) [5000 or 7500 IU] immediately prior to surgery, subcutaneous UFH [5000 IU, 7500 IU, or unspecified] immediately postoperatively, and either 10,000 or 14,000 IU of tinzaparin, beginning on the day after surgery, for 10 days. Intra-operative sequential compression devices could be used at the attending surgeon's discretion. Occurrence of VTE and major bleeding within 30 days of surgery were assessed.

RESULTS

A total of 389 patients were included for analysis, all patients received in-hospital follow-up while 349 patients had also 30-day follow-up. For the primary safety and efficacy analysis of in-hospital events, VTE and major bleeding rates were 0.26% [95% CI 0.01%-1.44%] (1/389) and 0.77% [95% CI 0.21%-2.24%] (3/389) respectively. For patients with 30-day follow-up VTE and major bleeding rates were 0.57% [95% CI 0.1%-2.07%] (2/349) and 1.43% [95% CI 0.61%-3.3%] (5/349) respectively.

CONCLUSIONS

Weight-adjusted tinzaparin was associated with a low risk of bleeding and VTE events, supporting its use for VTE prophylaxis for patients weighing ≥160 kg.

Direct Oral Anticoagulant Concentrations in Obese and High Body Weight Patients: A Cohort Study

BACKGROUND

 Direct oral anticoagulants (DOACs) are prescribed for atrial fibrillation (AF) and venous thromboembolism (VTE) and both occur more frequently in obese patients. Outcomes from DOAC trials included few individuals ≥ 120 kg leading to uncertainty whether high body weight (BW) reduces DOAC concentrations.

OBJECTIVES

 This article investigates the relationship between factor Xa (FXa) inhibitor concentrations, BW, and renal function, and compares them in high BW patients with unselected populations.

METHODS

 Consecutive patients in two United Kingdom centers, weighing ≥ 120 kg receiving 5 mg twice daily apixaban or 20 mg once daily rivaroxaban for AF or VTE were prospectively included. Peak or trough concentrations were measured using specific chromogenic assays, expressed in mean or median (5th-95th percentiles). On-therapy range was the interval from the 5th percentile trough concentration to the 95th percentile peak concentration.

RESULTS

 One hundred patients were included; age range: 23 to 78 years, 31% were women, 58% had AF, creatinine clearance range: 67 to 474 mL/min. Median BW was 139 kg, and 84% had body mass index (BMI) ≥ 40 kg/m². DOAC peak and trough concentrations varied from 44 to 727 and 14 to 299 ng/mL, respectively. There was no linear relationship between FXa inhibitor concentrations at peak or trough and BW or BMI, and creatinine clearance. Apixaban troughs in AF and rivaroxaban peaks in VTE were lower than in unselected populations. However, only two trough concentrations were below the expected range, and 109/116 were within the on-therapy range.

CONCLUSION

 These data indicated that obese or high BW patients generally achieve therapeutic FXa inhibitor concentrations. However, further investigations assessing clinical outcomes are required.