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

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.

Direct Oral Anticoagulants: Navigating Through Clinical Challenges

PURPOSE

Direct oral anticoagulants (DOACs) have been approved, for over a decade, by both European and American medicine agencies, for treatment and prevention of several cardiovascular conditions. Since then, an increasing amount of data has been added to the medical literature day by day, resulting in a dichotomy in selection of the appropriate agent, dosage, and duration of treatment for special populations with multiple comorbidities. Considering these issues, we have prepared a comprehensive review for the clinical practitioner, to optimize the DOAC utilization in clinical practice.

METHODS

A thorough literature search and review was conducted, concerning mainly the last decade. Our review focused on the current guidelines and the most recently published studies in PubMed, Science Direct Scopus, and Google Scholar to date.

CONCLUSION

The purpose of this study is to provide guidance for healthcare professionals for making proper decisions when confronted with clinical challenges. Nevertheless, further research is required to establish DOAC superiority in complicated cases, where there is clinical uncertainty.

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.

Comparing the Clinical Outcomes Observed with Rivaroxaban Versus Warfarin for the Management of Obese Patients with Non-valvular Atrial Fibrillation: a Systematic Review and Meta-analysis

BACKGROUND

Atrial fibrillation (AF) is an irregular heart rhythm which is becoming more and more common in this new era. Obesity is a risk factor for cardiovascular events, and obese patients are more at risk for stroke. The Framingham Heart Study demonstrated an increase in the developmental risk of AF by 4% for every unit (kg/m2) increase in body mass index (BMI). An anticoagulant is often required for the management of such patients. In this analysis, we aimed to systematically compare the clinical outcomes which were associated with rivaroxaban versus warfarin for the treatment of obese patients with non-valvular AF.

METHODS

PubMed, EMBASE, Web of Science, http://www.

CLINICALTRIALS

gov , Google Scholar, and Cochrane Central were the searched databases. Clinical outcomes including stroke, systemic embolism, and major bleeding were the endpoints. In this study, dichotomous data were analyzed by the RevMan software version 5.4. Risk ratio (RR) with 95% confidence interval (CI) was used for result interpretation.

RESULTS

Ten studies consisting of a total number of 168,081 obese participants were included whereby 81,332 participants were treated with rivaroxaban and 86,749 participants were treated with warfarin. The risks of ischemic (RR: 0.79, 95% CI: 0.74-0.84; P = 0.00001) and hemorrhagic stroke (RR: 0.61, 95% CI: 0.48-0.76; P = 0.0001) as well as systemic embolism (RR: 0.73, 95% CI: 0.62-0.87; P = 0.0004) were significantly lower with rivaroxaban compared to warfarin for the management of these obese patients with non-valvular AF. Rivaroxaban was also associated with a significantly lower risk of major bleeding (RR: 0.75, 95% CI: 0.65-0.87; P = 0.0001).

CONCLUSION

Based on this analysis, rivaroxaban seemed to be a better option in comparison to warfarin, due to its association with significantly lower risks of stroke and bleeding outcomes in obese patients with non-valvular AF. However, this hypothesis should further be confirmed in larger clinical trials.

Impact of Obesity on Atrial Fibrillation Pathogenesis and Treatment Options

Atrial fibrillation (AF) is the most common cardiac arrhythmia. AF increases the risk of stroke, heart failure, dementia, and hospitalization. Obesity significantly increases AF risk, both directly and indirectly, through related conditions, like hypertension, diabetes, and heart failure. Obesity-driven structural and electrical remodeling contribute to AF via several reported mechanisms, including adiposity, inflammation, fibrosis, oxidative stress, ion channel alterations, and autonomic dysfunction. In particular, expanding epicardial adipose tissue during obesity has been suggested as a key driver of AF via paracrine signaling and direct infiltration. Weight loss has been shown to reverse these changes and reduce AF risk and recurrence after ablation. However, studies on how obesity affects pharmacologic or interventional AF treatments are limited. In this review, we discuss mechanisms by which obesity mediates AF and treatment outcomes, aiming to provide insight into obesity-drug interactions and guide personalized treatment for this patient subgroup.

Therapeutic Drug Monitoring of Direct Oral Anticoagulants in Patients with Extremely Low and High Body Weight-Pilot Study

Phase III clinical trials for individual direct oral anticoagulants (DOACs) contained a limited representation of subjects with abnormal body weight, which were mostly limited to a BMI > 40 kg/m2, or body weight > 120 kg for obese subjects, and <50 kg for underweight subjects. Although low or high body weight is not a contraindication to DOACs therapy, it can significantly affect the safety and effectiveness of treatment. Due to the limited amount of clinical data on the use of DOACs in extremely abnormal weight ranges, optimal pharmacotherapy in this group of patients is a matter of controversy. The objective of this study was to evaluate the pharmacokinetics of DOAC properties in patients with abnormal body weight beyond the established cut-off points in the phase III studies for rivaroxaban, apixaban, and dabigatran. In total, 38 patients took DOACs for at least 12 months for non-valvular atrial fibrillation in 2019-2021. Blood samples were collected before the planned intake of the drug and 4 h after its administration. The determined concentrations of DOACs were statistically analyzed in relation to body weight, age, and eGFR (estimated Glomerular Filtration Rate). Among subjects taking apixaban, rivaroxaban, and dabigatran, the smallest representation of patients who achieved therapeutic concentrations were those treated with dabigatran. The population of people with abnormal body weight is a potential risk group of patients, in which some of them do not reach the therapeutic range of DOACs.

The Effectiveness and Safety of Direct Oral Anticoagulants in Obese Patients With Atrial Fibrillation: A Network Meta-Analysis

Atrial fibrillation (AF) is a cardiac condition characterized by an irregular heart rhythm, which is increasingly prevalent in the modern era. All international guidelines strongly advise the administration of anticoagulants to individuals with AF who are at high risk of stroke. These guidelines recommend the use of direct oral anticoagulants (DOACs) over warfarin because warfarin is significantly associated with increased rates of major bleeding, numerous interactions with food and drugs, and the necessity for frequent monitoring. The aim of this study is to compare the effectiveness and safety of direct oral anticoagulants (DOACs) in obese patients with atrial fibrillation. Two authors independently conducted a comprehensive literature search using electronic databases including PubMed, CINAHL, and EMBASE from inception to June 1, 2023. The efficacy outcome assessed in this meta-analysis included the composite of stroke and systemic embolism. For safety analysis, major bleeding events were compared among the study groups. Eleven studies fulfilled all the inclusion criteria and were included in the present meta-analysis enrolling 144,502 patients. In this study, DOACs demonstrate superior efficacy in preventing stroke/systemic embolism compared to warfarin. Among the DOACs, apixaban emerged as the most effective, followed by rivaroxaban, warfarin, and dabigatran. In terms of safety, apixaban was also found to be the most favorable treatment option, followed by rivaroxaban, dabigatran, and warfarin. In summary, our study concludes that apixaban exhibited greater effectiveness and safety when compared to other DOACs and warfarin in obese patients with AF.

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.

Study on effective synthesis of 7-hydroxy-4-substituted coumarins

Many coumarin derivatives have good biological activity and application value in fluorescent probes. Therefore, synthetic routes to coumarin derivatives have also attracted the attention of many research groups. In this work, based on the Pechmann coumarin synthesis method, the influence of various Lewis acids on the reaction was discussed, and the optimal synthesis conditions of 7-hydroxy-4-substituted coumarins were explored. Based on the experimental results, a possible mechanism was proposed, which provides a reference for future industrialized production of coumarins.

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.

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.

Direct oral anticoagulants versus warfarin in nonvalvular atrial fibrillation patients with prior gastrointestinal bleeding: a network meta-analysis of real-world data

PURPOSE

The objective of present study was to compare the safety and efficacy of resuming direct-acting oral anticoagulants (DOACs) and vitamin K antagonists (VKAs) in patients with atrial fibrillation (AF) and prior gastrointestinal bleeding (GIB).

METHODS

PubMed, Embase, Web of Science, and the Cochrane Library were searched from their inception until 2 June 2021 for observational cohort studies in patients with AF, who resumed VKAs or DOACs after a history of GIB. Studies that reported data on clinical outcomes including risk of recurrent GIB, thromboembolic events, or all-cause mortality were included. A network meta-analysis was performed to calculate the pooled hazard ratio (HR) and associated 95% credible intervals (CIs), using a random effects model in a Bayesian framework.

RESULTS

A total of 10 studies were included in the final analysis, including 59,244 AF patients with prior GIB, of whom 27,793 resumed DOACs, 24,635 resumed warfarin, and 6816 did not resume anticoagulation. Compared with no resumption of anticoagulation, resumption of warfarin was associated with an increased risk of recurrent GIB (HR 1.33, 95% CI: 1.06-1.70), but no increased risk of recurrent GIB was found with resumption of DOACs (HR 1.22, 95% CI: 0.88-1.71); among individual DOACs, only rivaroxaban was associated with an increased risk of recurrent GIB (HR 1.67, 95% CI: 1.16-2.65). Compared with no resumption of anticoagulation, resumption of DOACs and warfarin was associated with a significant reduction in all-cause mortality (HR 0.57, 95% CI: 0.40-0.84; HR 0.58, 95% CI: 0.44-0.79), but no statistically significant reduction in thromboembolic events (HR 0.69, 95% CI: 0.4-1.2; HR 0.83, 95% CI: 0.55-1.29).

CONCLUSIONS

In AF patients with prior GIB, resumption of DOACs may be safer, except for rivaroxaban.