Efficacy and Safety of Direct Oral Anticoagulants Versus Warfarin in Patients with Atrial Fibrillation Across BMI Categories: A Systematic Review and Meta-Analysis

Prognostic Impact of Body Mass Index in Atrial Fibrillation

Background/Objectives: Contradictory results have been reported regarding the influence of obesity on the prognosis of atrial fibrillation (AF). The present study aimed to explore the potential association of body mass index (BMI) with the clinical outcomes of hospitalized patients with AF. Methods: In this retrospective, post hoc analysis of the MISOAC-AF randomized trial, 1113 AF patients were included and stratified as the following: underweight (BMI < 18 kg/m2), normal weight (BMI 18-24.9 kg/m2), overweight (BMI 25-29.9 kg/m2), and obese (BMI ≥ 30 kg/m2). The primary outcome was all-cause mortality; the secondary composite outcome was any hospitalization related to AF, heart failure (HF), or stroke. Cox regression analysis, survival analysis, and spline curve models were utilized. Results: Of the patients (median age: 76 years (IQR: 13), male: 54.6%), the majority were overweight (41.4%), followed by obese (33%), normal weight (24%), and underweight (1.6%). During a median 31-month follow-up, 436 (39.2%) patients died and 657 (59%) were hospitalized due to AF, HF, or stroke. Underweight, overweight, and obesity groups were significantly associated with an increased risk of all-cause mortality (p-values 0.02, 0.001, and <0.001, respectively), while overweight and obesity were significantly associated with the composite endpoint (p-values 0.01, <0.001, respectively) compared to normal weight. The spline curve analyses yielded that BMIs > 26.3 and > 25 were incrementally associated with all-cause mortality and the composite endpoint, respectively. A J-shaped relationship between BMI and AF prognosis was deduced. Conclusions: In conclusion, in recently hospitalized AF patients, BMI values outside the normal range were independently associated with poorer prognosis; therefore, it is essential that AF patients maintain a normal weight.

Evaluation of Apixaban standard dosing in underweight patients with non-valvular atrial fibrillation: a retrospective cohort study

BACKGROUND

Recent guidelines recommend using direct oral anticoagulants (DOACs) as first-line agents in patients with non-valvular atrial fibrillation (NVAF). Research is currently investigating the use of Apixaban in underweight patients, with some results suggesting altered pharmacokinetics, decreased drug absorption, and potential overdosing in this population. This study examined the effectiveness and safety of standard Apixaban dosing in adult patients with atrial NVAF weighing less than 50 kg.

METHODS

This is a retrospective cohort study conducted at King Abdulaziz Medical City (KAMC); adult patients with a body mass index (BMI) below 25 who received a standard dose of Apixaban (5 mg twice daily) were categorized into two sub-cohorts based on their weight at the time of Apixaban initiation. Underweight was defined as patients weighing ≤ 50 kg, while the control group (Normal weight) comprised patients weighing > 50 kg. We followed the patients for at least one year after Apixaban initiation. The study's primary outcome was the incidence of stroke events, while secondary outcomes included bleeding (major or minor), thrombosis, and venous thromboembolism (VTE). Propensity score (PS) matching with a 1:1 ratio was used based on predefined criteria and regression model was utilized as appropriate.

RESULTS

A total of 1,433 patients were screened; of those, 277 were included according to the eligibility criteria. The incidence of stroke events was lower in the underweight than in the normal weight group at crude analysis (0% vs. 9.1%) p-value = 0.06), as well in regression analysis (OR (95%CI): 0.08 (0.001, 0.76), p-value = 0.002). On the other hand, there were no statistically significant differences between the two groups in the odds of major and minor bleeding (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 revealed that underweight patients with NVAF who received standard doses of Apixaban had fewer stroke events compared to normal-weight patients, without statistically significant differences in bleeding events. To confirm these findings, further randomized controlled trials with larger sample sizes and longer observation durations are required.

The safety and efficacy of nonvitamin K antagonist oral anticoagulants in morbidly obese patients with atrial fibrillation: a meta-analysis

BACKGROUND AND AIM

Atrial fibrillation (AF) is the most frequently observed cardiac arrhythmia in clinical settings. Obesity can influence the efficacy of the treatment administered, which requires a larger dose and more time to accomplish therapeutic targets due to altered pathophysiology. Our study aimed to assess the overall efficacy and safety of nonvitamin K antagonist oral anticoagulants (NOACs) versus warfarin in AF patients with morbid obesity (BMI > 40 kg/m2 and/or weight > 120 kg) to prevent complications.

METHODS

We conducted a literature search on PubMed, Web of Science, the Cochrane Library, and Scopus till October 2022 for articles addressing the efficacy and safety of NOACs versus warfarin for the treatment of AF in morbidly obese patients. We performed the meta-analysis with RevMan software version 5.4 and Open Meta Analyst. The main outcomes assessed were stroke, major bleeding, and minor bleeding after anticoagulation, as did the history of comorbidities and risk factors in morbidly obese patients. Quality assessment was performed using Cochrane's ROB-2 tool and the Newcastle-Ottawa scale.

RESULTS

Regarding major bleeding events, pooled data showed that patients taking NOACs had a significantly lower risk than patients taking warfarin (OR = 0.54, 95% CI: [0.41-0.70]; p < 0.00001). However, for minor bleeding, there was a nonsignificant effect of NOACs on reducing the risk of bleeding (OR = 0.72, 95% CI = 0.47-1.09; p = 0.12), which became highly significant in favor of NOACs after sensitivity analysis (OR = 0.55, 95% CI = 0.49-0.61]; p < 0.00001). There was a significant difference in the incidence of stroke between the NOAC group and the warfarin group (OR = 0.69, 95% CI = 0.60-0.80]; p < 0.00001). According to the results of the single-arm study analysis, the overall effect of all the outcomes was associated with a high risk of disease development in patients receiving NOACs.

CONCLUSION

Our meta-analysis showed a favorable effect of NOACs vs warfarin in morbidly obese patients. Some outcomes were not significantly different, which calls for future research to better assess their safety and efficacy in this particular weight group.

TRIAL REGISTRATION

The study was registered with PROSPERO under registration number CRD42022362493 on October 2022.

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.

Clinical Outcomes in Patients With Atrial Fibrillation Treated With Non-Vitamin K Oral Anticoagulants Across Varying Body Mass Index

Background There are conflicting data on outcomes in patients with atrial fibrillation treated with non-vitamin K oral anticoagulants across varying body mass index (BMI). We investigated cardiovascular and bleeding risk in patients with atrial fibrillation with varying BMI. Methods and Results Observational cohort study from the Swedish oral anticoagulation registry between August 2, 2011, and December 31, 2018. Primary outcomes were mortality, ischemic stroke/systemic embolism, and major bleeding. Baseline BMI (kg/m2) was analyzed continuously and categorized: underweight (<18.5 kg/m2), normal weight (18.5 to <25 kg/m2), preobesity (25 to <30 kg/m2), and obesity class I to III (30 to <35, 35 to <40, and ≥40 kg/m2). Adjusted Cox models and nonlinear relationships of BMI were modeled using restricted cubic splines. Non-vitamin K oral anticoagulant-treated patients with atrial fibrillation were included (n=26 047). At baseline, 602 (2.3%) were underweight, 9101 (34.9%) were normal weight, 9970 (38.3%) were preobese, 4280 (16.4%) were obese class I, 1486 (5.7%) were obese class II, and 608 (2.3%) were obese class III. Underweight and obesity class III were in adjusted continuous analysis associated with increased mortality and major bleeding, with lowest risk observed among preobese patients with BMI 28.2 and 26.2 kg/m2, respectively. In adjusted categorical analysis, underweight was associated with increased mortality (hazard ratio [HR], 1.77 [95% CI, 1.57-1.99]) and nonsignificant higher risk of major bleeding (HR, 1.23 [95% CI, 0.95-1.58]). Similarly, obesity class III was associated with increased mortality (HR, 1.67 [95% CI, 1.40-1.99]) and major bleeding (HR, 1.68 [95% CI, 1.29-2.17]). No significant association was observed between higher BMI and ischemic stroke/systemic embolism. Conclusions In non-vitamin K oral anticoagulant-treated patients with atrial fibrillation, there appears to be a U-shaped relationship between BMI and mortality and major bleeding.

Safety and efficacy of oral anticoagulants in extreme weights

BACKGROUND

The 2021 International Society on Thrombosis and Haemostasis' (ISTH) recommends standard doses of apixaban and rivaroxaban regardless of high body mass index (BMI) and weight, but had not compare DOACs head-to-head in obesity or address underweight patients.

METHODS

Our aim is to evaluate the safety and efficacy of DOACs in underweight and obese patients compared to warfarin. The primary endpoints include incidence of thromboembolic and bleeding events. Descriptive statistics was used for continuous variables. The Kruskal-Wallis test was used to compare the four-groups for continuous measures and the chi-square test or Fisher's exact test was used to analyze categorical data. The chi-square test or Fisher's exact test, was used for categorical variables, and the Mann-Whitney test (the non-parametric counterpart to the two-sample t-test) for continuous data.

RESULTS

Of 2940 patients receiving anticoagulation for venous thromboembolism (VTE) treatment or atrial fibrillation (AF), 492 met eligibility criteria. Within each group, 248 patients received warfarin, 101 received apixaban, 100 received rivaroxaban and 43 received dabigatran. Patients were characterized in 4 body mass index (BMI) categories, in which 80 were underweight and 412 were obese.

CONCLUSIONS

When each DOAC was compared to warfarin in rates of VTE, apixaban showed statistically significant lower rate of VTE (p = 0.0149). However, no statistical significance was identified in the rate of VTE between DOACs combined vs. warfarin (p = 0.1529). When each DOAC was compared to warfarin, apixaban showed the lowest rate of overall bleeding (p = 0.0194). However, no statistical difference in the rate of bleeding was observed between DOACs combined vs. warfarin (p = 0.3284). Patients with extreme body weights requiring anticoagulation for VTE and AF may safety benefit from DOAC therapy. This evaluation showed apixaban with the lowest rate of VTE and bleeding compared to warfarin, rivaroxaban, and dabigatran. These results provide experience for the clinician to use DOACs, particularly apixaban, in underweight and obese populations.

Effect of edoxaban compared with other oral anticoagulants for stroke prevention in patients with atrial fibrillation: A meta-analysis

Background and aim

Current observational studies have compared the effectiveness and safety of edoxaban with other oral anticoagulants in patients with AF, but the results are still disputed. This meta-analysis was conducted to compare the effect of edoxaban in patients with AF.

Methods

We performed systematic research from the PubMed, EMBASE, and Cochrane Library databases until November 2022 to obtain relevant observational studies. Adjusted risk ratios (RRs) and 95 % confidence intervals (CIs) of the outcomes were collected and pooled by a random-effects model. This study was prospectively registered in PROSPERO (CRD42022314222).

Results

A total of 17 observational studies were included in this meta-analysis. Compared with vitamin K antagonists, edoxaban was associated with lower risks of stroke or systemic embolism (RR = 0.67, 95 % CI:0.61-0.74), major bleeding (RR = 0.54, 95 % CI:0.44-0.67), and intracranial hemorrhage (RR = 0.51, 95 % CI:0.29-0.90). Compared with dabigatran or rivaroxaban, edoxaban was associated with reduced risks of stroke or systemic embolism (dabigatran [RR = 0.76, 95 % CI:0.66-0.87]; rivaroxaban [RR = 0.81, 95 % CI:0.70-0.94]) and major bleeding (dabigatran [RR = 0.82, 95 % CI:0.69-0.98]; rivaroxaban [RR = 0.81, 95 % CI:0.70-0.94]). Compared with apixaban, edoxaban was associated with a reduced risk of stroke or systemic embolism (RR = 0.87, 95 % CI:0.79-0.97), but had similar risks of bleeding events.

Conclusions

Our current evidence suggested that edoxaban might have superior effectiveness and/or safety outcomes than vitamin K antagonists, dabigatran, rivaroxaban, and apixaban for stroke prevention in patients with AF.

Integrated analysis of clinical and genetic factors on the interindividual variation of warfarin anticoagulation efficacy in clinical practice

AIM

The anticoagulation effect of warfarin is usually evaluated by percentage of time in therapeutic range (PTTR), which is negatively correlated with the risk of warfarin adverse reactions. This study aimed to explore the effects of genetic and nongenetic factors on anticoagulation efficacy of warfarin during different therapeutic range.

METHODS

We conducted an observational retrospective study aiming at evaluating the impact of clinical and genetic factors on PTTR from initial to more than six months treatment. This analysis included patients with heart valve replace (HVR) surgery who underwent long-term or life-long time treatment with standard-dose warfarin for anticoagulation control in Second Xiangya Hospital. All patients were followed for at least 6 months. We genotyped single nucleotide polymorphisms in VKORC1 and CYP2C9 associated with altered warfarin dose requirements and tested their associations with PTTR.

RESULTS

A total of 629 patients with intact clinical data and available genotype data were enrolled in this study, and only 38.63% patients achieved good anticoagulation control (PTTR > 0.6). Clinical factors, including male gender, older age, overweight, AVR surgery and stroke history, were associated with higher PTTR. Patients with VKORC1 -1639AA genotype had significantly higher PTTR level compared with GA/GG genotype carriers only in the first month of treatment. Patients with CYP2C9*3 allele had higher PTTR compared with CYP2C9*1*1 carriers. Moreover, compared with VKORC1 -1639 AG/GG carriers, INR > 4 was more likely to be present in patients with AA genotype. The frequency of CYP2C9*1*3 in patients with INR > 4 was significantly higher than these without INR > 4.

CONCLUSION

We confirmed the relevant factors of warfarin anticoagulation control, including genetic factors (VKORC1 -1639G > A and CYP2C9*3 polymorphisms) and clinical factors (male gender, older age, overweight, AVR surgery and stroke history), which could be helpful to individualize warfarin dosage and improve warfarin anticoagulation control during different treatment period.

Severe Bleeding Risk of Direct Oral Anticoagulants Versus Vitamin K Antagonists for Stroke Prevention and Treatment in Patients with Atrial Fibrillation: A Systematic Review and Network Meta-Analysis

PURPOSE

We aimed to determine the safety of direct oral anticoagulants (DOACs) for stroke prevention and treatment in patients with atrial fibrillation (AF).

METHODS

A systematic search of four databases (PubMed, EMBASE, Web of Science, and Cochrane Library) was performed to identify randomized controlled trials (RCTs) reporting severe bleeding events in patients taking DOACs or vitamin K antagonists (VKAs). In this frequency-based network meta-analysis, odds ratios and 95% confidence intervals were used for reporting. Based on the surface under the cumulative ranking curves (SUCRA), the relative ranking probability of each group was generated.

RESULTS

Twenty-three RCTs met the inclusion criteria, and a total of 87,616 patients were enrolled. The bleeding safety of DOACs for stroke prevention and treatment in patients with AF was ranked from highest to lowest as follows: fatal bleeding: edoxaban (SUCRA,80.2), rivaroxaban (SUCRA,68.3), apixaban (SUCRA,48.5), dabigatran (SUCRA,40.0), VKAs (SUCRA,12.9); major bleeding: dabigatran (SUCRA,74.0), apixaban (SUCRA,71.5), edoxaban (SUCRA,66.5), rivaroxaban (SUCRA,22.7), VKAs (SUCRA,15.4); gastrointestinal bleeding: apixaban (SUCRA,55.9), VKAs (SUCRA,53.7), edoxaban (SUCRA,50.5), rivaroxaban (SUCRA,50.4), dabigatran (SUCRA,39.5); intracranial hemorrhage: dabigatran (SUCRA,84.6), edoxaban (SUCRA,74.1), apixaban (SUCRA,65.8), rivaroxaban (SUCRA,24.4), VKAs (SUCRA,1.1).

CONCLUSION

Based on current evidence, for stroke prevention and treatment in patients with AF, the most safe DOAC is edoxaban in terms of fatal bleeding; dabigatran in terms of major bleeding and intracranial hemorrhage and apixaban in terms of gastrointestinal bleeding. However, given the nature of indirect comparisons, more high-quality evidence from head-to-head comparisons is still needed to confirm them.

Personalizing Direct Oral Anticoagulant Therapy for a Diverse Population: Role of Race, Kidney Function, Drug Interactions, and Pharmacogenetics

Oral anticoagulants (OACs) are commonly used to reduce the risk of venous thromboembolism and the risk of stroke in patients with atrial fibrillation. Endorsed by the American Heart Association, American College of Cardiology, and the European Society of Cardiology, direct oral anticoagulants (DOACs) have displaced warfarin as the OAC of choice for both conditions, due to improved safety profiles, fewer drug-drug and drug-diet interactions, and lack of monitoring requirements. Despite their widespread use and improved safety over warfarin, DOAC-related bleeding remains a major concern for patients. DOACs have stable pharmacokinetics and pharmacodynamics; however, variability in DOAC response is common and may be attributed to numerous factors, including patient-specific factors, concomitant medications, comorbid conditions, and genetics. Although DOAC randomized controlled trials included patients of varying ages and levels of kidney function, they failed to include patients of diverse ancestries. Additionally, current evidence to support DOAC pharmacogenetic associations have primarily been derived from European and Asian individuals. Given differences in genotype frequencies and disease burden among patients of different biogeographic groups, future research must engage diverse populations to assess and quantify the impact of predictors on DOAC response. Current under-representation of patients from diverse racial groups does not allow for proper generalization of the influence of clinical and genetic factors in relation to DOAC variability. Herein, we discuss factors affecting DOAC response, such as age, sex, weight, kidney function, drug interactions, and pharmacogenetics, while offering a new perspective on the need for further research including frequently excluded groups.

Associations of peroxisome proliferator-activated receptor-γ Pro12Ala polymorphism with non-alcoholic fatty liver disease: A meta-analysis

BACKGROUND

Polymorphisms in peroxisome proliferator-activated receptor-γ pro12Ala (PPAR-γ Pro12Ala) have been associated with Non-alcoholic Fatty Liver Disease (NAFLD) in several studies. However, the results of these studies are not entirely consistent. Thus, we performed a meta-analysis to investigate the association between the PPAR-γ Pro12Ala polymorphisms and NAFLD.

METHODS

Studies were identified by searching PubMed database and manual assessment of the cited references in the retrieved articles. Study-specific relative risks (RRs) and 95 % confidence intervals (CIs) were estimated using a random-effect model. Study quality was assessed using the Newcastle-Ottawa scale.

RESULTS

Relevant medical researches show that 11 studies have been conducted on the analysis of NAFLD for meta-analysis, with a total of 2404 cases and 3959 participating controls. Meta-analysis results show that PPAR-γ Pro12Ala polymorphism and NALAD Ala alleles[no association between dominance model (OR = 0.968, 95%CI: 0.734-1.276, P = 0.815); Pro/Ala vs. Pro/Pro (OR = 0.930, 95 % CI: 0.701-1.233, P = 0.612); Ala/Ala vs. Pro/Pro (OR = 1.220, 95 % CI: 0.668-2.230, P = 0.518); recessive model (OR = 0.907, 95 % CI: 0.516-1.596, P = 0.736)]. Moreover, stratification by ethnicity also revealed that no matter it is in Caucasian populations or in Asian populations, NAFLD has no association with the PPAR-γ Pro12Ala polymorphism.

CONCLUSIONS

According to the meta-analysis, both in Asians and Caucasian populations, the PPAR-γ Pro12Ala polymorphism can't be demonstrated to have any link with susceptibility to NAFLD.

Use of non-vitamin K antagonists oral anticoagulants in atrial fibrillation patients on dialysis

Background

Non-vitamin K antagonist oral anticoagulants (NOACs) showed a benefit-risk profile superior to that of warfarin in atrial fibrillation (AF) patients with mild to moderate chronic kidney disease. However, the effectiveness and safety of NOACs in AF patients with end-stage renal disease (ESRD) on dialysis remain unclear. Therefore, we performed a meta-analysis regarding the effect of NOACs vs. warfarin in AF patients undergoing dialysis.

Methods

A search of the Pubmed and EMBASE databases until November 2021 was performed. Adjusted risk ratios (RRs) and 95%confidence intervals (CIs) were pooled by a random-effects model with an inverse variance method.

Results

Six studies involving 3,744 NOAC- and 26,973 warfarin- users were deemed to meet the criteria. In the pooled analysis, the use of mixed NOACs had similar incidences of effectiveness and safety outcomes compared with warfarin use. And factor Xa inhibitors (rivaroxaban or apixaban) did not have significantly better effectiveness than warfarin. For the safety outcomes, the use of factor Xa inhibitors was associated with a reduced risk of gastrointestinal bleeding (RR = 0.81, 95% CI 0.70–0.95), but not major bleeding and intracranial bleeding.

Conclusion

Compared with warfarin, the use of NOACs, especially factor Xa inhibitors (rivaroxaban or apixaban), showed at least similar effectiveness and safety outcomes in AF patients on dialysis.

Rivaroxaban Monotherapy in Atrial Fibrillation and Stable Coronary Artery Disease Across Body Mass Index Categories

Background

The AFIRE (Atrial Fibrillation and Ischemic Events With Rivaroxaban in Patients With Stable Coronary Artery Disease) trial showed both noninferiority for efficacy and superiority for safety endpoints of rivaroxaban monotherapy compared with those of rivaroxaban plus antiplatelet therapy (combination therapy) in patients with atrial fibrillation and stable coronary artery disease.

Objectives

This study sought to evaluate outcomes of rivaroxaban monotherapy in those patients across body mass index (BMI) categories.

Methods

Patients were categorized into 4 groups: underweight (BMI <18.5 kg/m²), normal weight (BMI 18.5 to <25 kg/m²), overweight (BMI 25 to <30 kg/m²), and obesity (BMI ≥30 kg/m²). Efficacy (a composite of all-cause death, myocardial infarction, unstable angina requiring revascularization, stroke, or systemic embolism) and safety (major bleeding defined according to International Society on Thrombosis and Haemostasis criteria) were compared between rivaroxaban monotherapy and combination therapy across BMI categories.

Results

This study analyzed 2,054 patients with a median age of 75.0 years and CHA₂DS₂-VASc score of 4. A significant interaction was not observed between BMI categories and effect of monotherapy for efficacy (P = 0.83) and safety (P = 0.07), although monotherapy was superior to combination therapy for efficacy in normal weight (HR: 0.64; 95% CI: 0.44-0.95) and safety in overweight (HR: 0.25; 95% CI: 0.10-0.62), whereas a significant difference in the endpoints was not observed in the other BMI categories.

Conclusions

Rivaroxaban monotherapy had a similar effect on prognosis across all BMI categories in patients with atrial fibrillation and stable coronary artery disease. (Atrial Fibrillation and Ischemic Events With Rivaroxaban in Patients With Stable Coronary Artery Disease [AFIRE]; UMIN000016612, NCT02642419).

Meta-Analysis of Oral Anticoagulants and Adverse Outcomes in Atrial Fibrillation Patients After Intracranial Hemorrhage

Background

Intracranial hemorrhage (ICH) is excluded in most anticoagulation randomized clinical trials (RCTs), so oral anticoagulant (OAC) therapy is still the conventional treatment for patients with atrial fibrillation (AF) after ICH. Therefore, we conducted a meta-analysis to determine the effectiveness and safety outcomes of OAC for these patients.

Methods

We systematically searched the PubMed and Embase databases up to March 2022 for RCTs and observational studies exploring the effect of OAC in patients with AF after ICH. The effectiveness outcomes included stroke or systemic embolism, ischemic stroke, and all-cause death, whereas the safety outcomes were major bleeding and recurrent ICH. Hazard ratios (HRs) and 95% confidence intervals (CIs) from each study were pooled using a random-effects model.

Results

A total of 14 studies were included. The OAC therapy that was performed reduced the risks of stroke or systemic embolism (HR = 0.65, 95% CI 0.53–0.81), ischemic stroke (HR = 0.70, 95% CI 0.60–0.82), and all-cause death (HR = 0.43, 95% CI 0.27–0.70) but had a higher risk of major bleeding (HR = 1.50, 95% CI 0.94–2.40) and showed no difference in recurrent ICH (HR = 0.91, 95% CI 0.53–1.55) compared to the no OAC therapy. With the use of non-vitamin K antagonist oral anticoagulant (NOAC) therapy, a lower risk of stroke or systemic embolism (HR = 0.83, 95% CI 0.70–0.98), all-cause death (HR = 0.67, 95% CI 0.53–0.84), and recurrent ICH (HR = 0.68, 95% CI 0.54–0.86) was observed against the use of vitamin K antagonists (VKA) therapy.

Conclusion

The OAC therapy (especially VKA) revealed superior effectiveness in patients with AF after ICH, and the superiority of NOAC was also found, but some related evidence was limited.

[Time in therapeutic range and incidence of warfarin complications in a 20-year retrospective cohort]

Objetivo

Caracterizar el tiempo en rango terapéutico (TTR) y estimar la tasa de incidencia de complicaciones (PTIRc) en adultos con protocolo de warfarina.

Diseño

Cohorte retrospectiva basada en registros médicos de pacientes mayores de 18 años entre 1996 a 2016 y seguidos al menos tres meses.

Emplazamiento

Unidad de Hematología de un centro especializado cardiovascular venezolano.

Participantes

Registros médicos electrónicos.

Mediciones principales

TTR y PTIRc. Las variables fueron: sexo, analfabetismo funcional, ocupación, international normalized ratio (INR) y tiempo de seguimiento, que fueron analizados con TTR and PTIRc mediante modelos de logística binomial y regresión de Poisson, respectivamente.

Resultados

Un total de 2.770 pacientes fueron seguidos durante 1.201.380 días; el 42,3% tuvieron un TTR < 65% y el 3,5% tuvieron indicación de INR 2,5-3,5. El 61,8% presentaron complicaciones. La PTIRc fue de 6,84/100 personas-mes (IC 95%: 6,56-7,15). TTR < 65% mostró OR ajustadas significativas con analfabetismo funcional e INR 2,5-3,5, mientras que para la mayor PTIRc se encontró un RR significativo en los dos factores mencionados, menor tiempo de seguimiento, TTR < 65% y en mujeres.

Conclusiones

A pesar de nuevos tratamientos anticoagulantes, la warfarina es útil. A medida que aumentó el tiempo de seguimiento el control fue mejor y la velocidad de aparición de complicaciones disminuyó; sin embargo, las condiciones que mostraron menor TTR y mayor velocidad de aparición de complicaciones requieren una profunda revisión del seguimiento, de manera especial en pacientes con analfabetismo funcional.

Intraocular Bleeding in Patients With Atrial Fibrillation Treated With NOACs VS. Warfarin: A Systematic Review and Meta-Analysis

Background

Intraocular bleeding is a devastating adverse event for patients with atrial fibrillation (AF) receiving anticoagulant therapy. It is unknown whether non-vitamin K oral anticoagulants (NOACs) compared with warfarin can reduce the risk of intraocular bleeding in patients with AF. Herein, we conducted a meta-analysis to evaluate the effect of NOACs vs. warfarin on intraocular bleeding in the AF population.

Methods

Studies were systematically searched from the Embase, PubMed, and Cochrane databases until April 2022. We included studies if they enrolled patients with AF and compared the intraocular bleeding risk between NOACs and warfarin and if they were randomized controlled trials (RCTs) or observational cohort studies. The random-effects model was chosen to evaluate the pooled odds ratios (ORs) and 95% confidence intervals (CIs).

Results

A total of 193,980 patients with AF from 5 randomized controlled trials (RCTs) and 1 cohort study were included. The incidence of intraocular bleeding among AF patients treated with warfarin and NOACs was 0.87% (n = 501/57346) and 0.61% (n = 836/136634), respectively. In the pooled analysis with the random-effects model, the use of NOACs was not significantly associated with the risk of intraocular bleeding (OR = 0.74; 95% CI 0.52–1.04, P = 0.08) compared with warfarin use. In addition, the sensitivity analysis with the fixed-effects model suggested that NOAC users had a lower incidence of intraocular bleeding than patients with warfarin (OR = 0.57; 95% CI 0.51–0.63, P < 0.00001).

Conclusions

Our current meta-analysis suggested that the use of NOACs had no increase in the incidence of intraocular bleeding compared with warfarin use in patients with AF. Whether the use of NOACs is superior to warfarin needs more research to confirm.

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

Direct Oral Anticoagulants vs. Vitamin K Antagonists in Atrial Fibrillation Patients at Risk of Falling: A Meta-Analysis

Background

Direct oral anticoagulants (DOACs) and warfarin are usually used for people with atrial fibrillation (AF). However, for the AF patients at risk of falling, the effectiveness and safety outcomes of DOACs compared with warfarin remain unclear. Therefore, we performed a meta-analysis regarding the effectiveness and safety of DOACs vs. warfarin in AF patients at risk of falling.

Methods

A search of the PubMed and Embase databases until November 2021 was performed. We included studies if they satisfied the following criteria: (1) study type: randomized clinical trials or observational cohort studies. (2) Comparisons: effectiveness and/or safety of DOACs (dabigatran, rivaroxaban, apixaban, or edoxaban) compared with warfarin. (3) Study data: the sample size, the number of events in the VKAs or DOACs groups, adjusted risk ratios (RRs), and 95% confidence intervals (CIs). (4) Study outcomes: stroke or systemic embolism (SSE), ischemic stroke, myocardial infarction (MI), all-cause death, and cardiovascular death; major bleeding, major or clinically relevant non-major (CRNM) bleeding, intracranial bleeding, gastrointestinal bleeding, and any bleeding. (5) Study population: patients at risk of falling. According to the Morse Fall Scale, the risk of falling relates to the history of falling, secondary diagnosis, ambulatory aids, intravenous therapy, type of gait, and mental status. In this meta-analysis, if the patient's MFS score is ≥25 points, he will be thought of as having the risk of falling. The adjusted risk ratios (RRs) and 95% confidence intervals (CIs) were pooled by a random-effects model with an inverse variance method.

Results

Three cohort studies were included in our study. For the effectiveness outcomes, the use of DOACs was only associated with a significantly reduced risk of hemorrhagic stroke (RR = 0.28, 95%CI:0.10-0.75) compared with warfarin, but there were no significant differences in stroke or systemic embolism (SSE) (RR = 0.87, 95%CI:0.70-1.08), cardiovascular death (RR = 0.97, 95%CI:0.73-1.29) and all-cause death (RR = 0.90, 95%CI:0.72-1.11). For the safety outcomes, the use of DOACs was significantly associated with reduced risks of major or clinically relevant non-major bleeding (RR = 0.77, 95%CI:0.61-0.98) and intracranial bleeding (RR = 0.26, 95%CI:0.11-0.66) but not major bleeding (RR = 0.78, 95%CI:0.58-1.06).

Conclusions

Compared with warfarin, the use of DOACs in AF patients at risk of falling is significantly associated with reduced risks of hemorrhagic stroke, major or clinically relevant non-major bleeding, and intracranial bleeding.

Safety and efficacy of direct oral anticoagulants in comparison with warfarin across different BMI ranges: A systematic review and meta-analysis

Background

Many publications have compared various outcomes defining safety and efficacy of DOACs across different BMI ranges. Our meta-analysis compares warfarin and DOACs for its treatment effects over different BMI ranges.

Methods

A systematic search was conducted from inception to May 2021 on PubMed, Scopus and Embase databases. The data was extracted and pooled using a random effects model. Our study consisted of patients being treated for VTE and AF, across different BMI categories. For the comparison of DOAC, risk ratios (RR) with 95% confidence intervals (CIs) were used, whilst for the second comparison between warfarin and DOACs odds ratios (OR) were used.

Results

In our first comparison, 12 studies (n = 254,908 patients) were included. For our second comparison, six studies (n = 109,609 patients) were included. Major bleeding events in the underweight group were higher than normal weight [RR: 1.89 (1.10, 3.23); P = 0.02; I² = 0%]. Overweight patients were related with reduced rates of VTE than in patients with normal BMI [RR: 0.86 (0.76, 0.97); P = 0.02; I² = 0%]. In comparison with patients receiving warfarin, DOACs had significantly reduced risk of major bleeding in normal weight, overweight and obese [OR: 0.64 (0.49, 0.83); P = 0.0007 I² = 90%].

Conclusion

The risk of VTE reduces with an increasing BMI, hence there could be a possible obesity paradox in patients with anticoagulation therapy. In comparison to warfarin, DOACs proved to be the safer option by having a reduced risk of bleeding across all BMI categories.

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Warfarin therapy and its effectiveness for prevention of thromboembolism.

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Effect of warfarin and DOACs over different BMI ranges.

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Safety and efficacy of DOACs across different BMI ranges.

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Lower risk of bleeding in normal weight, overweight, and obese patients with DOACs.

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Warfarin and DOACs across different BMI categories in VTE and AF patients.

Observed Apixaban Anti-Xa Levels in Obese Patients

BACKGROUND

Recent guidelines suggest that, for venous thromboembolism (VTE), standard doses of apixaban are appropriate in patients with body mass index (BMI) >40 kg/m2 or >120 kg. Atrial fibrillation (AF) is excluded from this recommendation.

OBJECTIVE

The goals of our study were to measure and describe anti-Xa levels of patients with a BMI ≥40 kg/m2 and/or a weight ≥120 kg with a clinical indication of AF or VTE who were treated with apixaban, and to determine whether BMI or weight are associated with anti-Xa levels in this population.

METHODS

We conducted an observational cohort study at a single health care system in Oregon, USA. Patients meeting enrollment criteria were recruited and had peak and trough apixaban anti-Xa levels drawn.

RESULTS

Of 55 patients enrolled, 5 (9%) had peak anti-Xa levels below the reference range and 3 (6%) had trough anti-Xa levels below the reference range. BMI did not significantly correlate with peak or trough anti-Xa levels (r = -0.10, p = 0.45 and r = -0.14, p = 0.31). Weight had a moderate, negative correlation with peak anti-Xa levels (r = -0.42, p = 0.002) and a weak, negative correlation with trough anti-Xa levels (r = -0.32, p = 0.02).

CONCLUSIONS AND RELEVANCE

This study provides evidence that anti-Xa levels among obese patients are not substantially different from patients with nomral BMI and weight. This supports recent ISTH guidance for standard dosing of apixaban for VTE patients with BMI >40 kg/m2 or weight >120 kg and provides additional evidence that the standard dosing may also be appropriate in patients with AF.

Expert Recommendations on the Usage of Non-vitamin K Antagonist Oral Anticoagulants (NOACs) from India: Current Perspective and Future Direction

Non-vitamin K antagonist oral anticoagulants (NOACs) are a new class of anticoagulant drugs used in the prevention and treatment of venous thromboembolism (VTE) and atrial fibrillation (AF). Anticoagulation requires the integration of the correct type and dose of oral anticoagulants based on patient characteristic, and therefore therapy needs to be individualized for each patient. Growing scientific evidence from studies on NOACs has led to a better understanding of their benefits and safety. A large amount of available data creates a necessity for an adaptable practical document for the usage of NOACs in India. The current consensus, developed by experts from India, aims to give recommendations on various frequently raised clinical questions with regards to NOACs and its usage. This practical document provides a platform upon which future guidelines, policies, training, and education for the use of NOACs can be tailored.

Comparative Effectiveness and Safety of DOAC Versus 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.

Obesity Paradox in Atrial Fibrillation and its Relation with the New Oral Anticoagulants

Obesity, a chronic disease established as a global epidemic by the World Health Organization, is considered a risk factor for atrial fibrillation (AF), the most common sustained cardiac arrhythmia, which has high morbidity and mortality. Although both obesity and AF are diseases associated with negative outcomes, studies have shown the presence of an obesity paradox, in which patients with a high body mass index (BMI) and AF have a better prognosis than patients with a normal BMI. Despite the fact that the mechanisms that lead to this paradox are still uncertain, adequate anticoagulation in obese patients seems to play an important role in reducing adverse events in this group. In this perspective article, the authors discuss the relationship between new oral anticoagulants (NOACs), namely, apixaban, edoxaban and rivaroxaban (factor Xa inhibitors) and dabigatran (direct inhibitor of thrombin), and the obesity paradox, seeking to deepen the understanding of the mechanism that leads to this paradox.

Apixaban and rivaroxaban use for atrial fibrillation in patients with obesity and BMI ≥50 kg/m2

BACKGROUND

Apixaban and rivaroxaban are increasingly used for thromboembolism prophylaxis in patients with non-valvular atrial fibrillation (NVAF) and commonly in patients with obesity and body mass index (BMI) ≥50 kg/m² despite the limited data.

OBJECTIVES

This study aimed to establish the effectiveness and safety of apixaban and rivaroxaban in patients with NVAF and BMI ≥50 kg/m² .

METHODS

A single health-system, retrospective cohort study evaluated the effectiveness and safety of apixaban and rivaroxaban initiated in adult patients (≥18 years of age) with BMI ≥50 kg/m² and NVAF. Outcomes of ischemic stroke, systemic embolic events, and bleeding were compared to a cohort of patients with BMI 18 to 30 kg/m² .

RESULTS

After 1619 patient-years worth of follow-up in 595 patients, the primary endpoint of incidence of ischemic stroke was numerically similar in both groups, 1.3 per 100 patient-years in the BMI ≥50 kg/m²  group, compared to 2.0 per 100 patient-years in the BMI <30 kg/m²  group (RR 0.65, 95% CI 0.38-1.82, p = 0.544). Incidence of major bleeding and clinically relevant non-major bleeding was also numerically similar between the two groups.

CONCLUSIONS

This study demonstrated that apixaban and rivaroxaban in patients with a BMI ≥50 kg/m² for treatment of NVAF may be safe and effective at preventing thromboembolic events and had no increased risk of bleeding. Although, findings should be interpreted with caution and confirmed with additional studies. This study contributes to the growing body of evidence that direct oral anticoagulants (DOACs) may be effective and safe to use for the treatment of NVAF in patients with BMI ≥50 kg/m² .

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.

Association of Chronic Obstructive Pulmonary Disease With Arrhythmia Risks: A Systematic Review and Meta-Analysis

Background: A large number of studies have shown that the arrhythmia risks may be the potential causes of death among chronic obstructive pulmonary disease (COPD) patients. However, the association of COPD with risks of arrhythmias has never been systematically reviewed. Therefore, we performed a meta-analysis to assess the relationship between COPD and arrhythmia risks.

Methods: An updated systematic retrieval was carried out within the databases of Embase and PubMed until June 27, 2021.The random-effects model was used to pool studies due to the potential heterogeneity across the included studies. The risk ratios (RRs) with 95% confidence intervals (CIs) were regarded as effect estimates.

Results: A total of 21 studies were included in our meta-analysis. In the pooled analysis by the random-effects model, the results showed that COPD was significantly related to the risk of atrial fibrillation (AF) (RR = 1.99, 95% CI: 1.46–2.70), ventricular arrhythmias (VA) (RR = 2.01, 95% CI: 1.42–2.85), and sudden cardiac death (SCD) (RR = 1.68, 95% CI: 1.28–2.21). The corresponding results were not changed after exclusion one study at a time. The pooled results were also stable when we re-performed the analysis using the fixed-effects model.

Conclusions: Our current data suggested that COPD was associated with increased risks of AF, VA, and SCD.

Off-Label Underdosing or Overdosing of Non-vitamin K Antagonist Oral Anticoagulants in Patients With Atrial Fibrillation: A Meta-Analysis

Background: Several studies have investigated the role of off-label non-vitamin K antagonist oral anticoagulants (NOACs) in patients with atrial fibrillation (AF). We aimed to compare the effectiveness and safety outcomes between off-label underdose or overdose vs. on-label dose of NOACs in AF patients.

Methods: The PubMed database was systematically searched until August 2021. Observational cohorts were included if they compared the outcomes of off-label underdose or overdose with on-label dose of NOACs in AF patients. The risk ratios (RRs) and 95% confidence intervals (CIs) were pooled using a fixed-effects model (I² ≤ 50%) or a random-effects model (I² > 50%).

Results: A total of 15 observational studies were included. Compared with on-label dose of NOACs, off-label underdose of NOACs was associated with increased risks of stroke or systemic embolism (RR = 1.09, 95% CI 1.02–1.16), and all-cause death (RR = 1.29, 95% CI 1.10–1.52) but not ischemic stroke (RR = 1.34, 95% CI 0.76–2.36), myocardial infarction (RR = 1.08, 95% CI 0.92–1.28), major bleeding (RR = 0.97, 95% CI 0.89–1.05), intracranial hemorrhage (RR = 1.12, 95% CI 0.90–1.40), and gastrointestinal bleeding (RR = 0.96, 95% CI 0.85–1.07), whereas off-label overdose of NOACs was associated with increased risks of SSE (RR = 1.20, 95% CI 1.05–1.36), all-cause death (RR = 1.22, 95% CI 1.06–1.39), and major bleeding (RR = 1.33, 95% CI 1.16–1.52) but not gastrointestinal bleeding (RR = 1.18, 95% CI 0.99–1.42) and myocardial infarction (RR = 0.98, 95% CI 0.75–1.30).

Conclusion: Compared with on-label dose of NOACs, off-label underdose was associated with increased risks of stroke or systemic embolism and all-cause death, whereas off-label overdose of NOACs was associated with increased risks of stroke or systemic embolism, all-cause death, and major bleeding.

Direct Oral Anticoagulants in Patients with Obesity and Atrial Fibrillation: Position Paper of Italian National Association of Hospital Cardiologists (ANMCO)

The use of the direct oral anticoagulants dabigatran, rivaroxaban, apixaban and edoxaban (DOACs) offers some major advantages over warfarin and other vitamin K antagonists (VKAs). One advantage is the possibility to use a fixed dose in normal-weight patients, overweight patients and patients with obesity. However, the "one size fits all" strategy raised a concern regarding the possibility to undertreat patients with a high body mass index. No randomized controlled trials (RCTs) have ever compared VKAs and DOACs in this population. We analyzed data from the literature on DOAC pharmacokinetics and pharmacodynamics, results from the four pivotal phase III trials on non-valvular atrial fibrillation, retrospective observational studies and metanalyses. While we are aware of the limitation imposed by the absence of specific RCTs, we propose the position of the Italian Association of Hospital Cardiologists (ANMCO) on the use of DOACs in patients with obesity based on the existing evidence.

Association of smoking with postoperative atrial fibrillation in patients with cardiac surgery: A PRISMA-compliant article

BACKGROUND

Cigarette smoking is an important modifiable risk factor for incident atrial fibrillation. However, the impact of smoking on postoperative atrial fibrillation in patients undergoing cardiac surgery remains controversial. We performed this meta-analysis to explore the association of smoking with postoperative atrial fibrillation in patients with cardiac surgery.

METHODS

We systematically searched 2 computer-based databases (PubMed and EMBASE) up to July 2019 for all relevant studies. A random-effects model was selected to pool the odds ratios (ORs) and 95% confidence intervals (CIs). In this meta-analysis, the protocol and reporting of the results were based on the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement.

RESULTS

A total of 36 studies were included in this meta-analysis. Overall, smoking was not associated with an increased risk of postoperative atrial fibrillation in patients undergoing cardiac surgery (odds ratio [OR] = 0.89; 95% confidence interval [CI] 0.79-1.02). The corresponding results were stable in the subgroup analyses. Specifically, smoking was not associated with an increased risk of postoperative atrial fibrillation regardless of the type of cardiac surgery: coronary artery bypass grafting (OR = 0.91; 95% CI 0.77-1.07), valve surgery (OR = 0.15; 95% CI 0.01-1.56), and coronary artery bypass grafting+valve surgery (OR = 0.91; 95% CI 0.70-1.18).

CONCLUSIONS

Based on currently published studies, smoking was not associated with an increased risk of postoperative atrial fibrillation in patients undergoing cardiac surgery.

Non-vitamin K antagonist oral anticoagulants versus vitamin K antagonists in atrial fibrillation patients with previous stroke or intracranial hemorrhage: A systematic review and meta-analysis of observational studies

Several observational studies have compared the effectiveness and safety outcomes between nonvitamin K antagonist oral anticoagulants (NOACs) and vitamin K antagonists (VKAs) in atrial fibrillation (AF) patients with a history of either stroke/transient ischemic attack (TIA) or intracranial hemorrhage. Therefore, our current meta-analysis aimed to address this issue. The Cochrane Library, PubMed, and Embase databases were systematically searched until December 2020 for all relevant observational studies. We applied a random-effects model to pool adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for this meta-analysis. A total of 10 studies were included. Among patients with a history of stroke/TIA, the use of NOACs versus VKAs was associated with decreased risks of stroke (HR, 0.82, 95% CI 0.69-0.97), systemic embolism (HR, 0.73, 95% CI 0.61-0.87), all-cause death (HR, 0.87, 95% CI 0.81-0.94), major bleeding (HR, 0.77, 95% CI 0.64-0.92) and intracranial hemorrhage (HR, 0.54, 95% CI 0.38-0.77). Among patients with a history of intracranial hemorrhage, the use of NOACs versus VKAs was associated with reduced risks of stroke (HR, 0.81, 95% CI 0.68-0.95), all-cause death (HR, 0.68, 95% CI 0.49-0.94), and intracranial hemorrhage (HR, 0.66, 95% CI 0.51-0.84). Compared with VKAs, the use of NOACs exhibited superior efficacy and safety outcomes in AF patients with previous stroke/TIA, and the use of NOACs was associated with reduced risks of stroke, all-cause death, and intracranial hemorrhage in patients with a history of intracranial hemorrhage.

Direct-Acting Oral Anticoagulants in Atrial Fibrillation: What's New in the Literature

Atrial fibrillation (AF) is considered the most common sustained cardiac arrhythmia, and it is associated with a significant risk of adverse events, especially ischemic stroke. Oral anticoagulation is the cornerstone for stroke prevention in AF; for many years, only vitamin K antagonists were used for this purpose, with an absolute risk reduction >60%. However, these agents have limitations, such as narrow therapeutic margins and drug-food and drug-drug interactions. More recently, 4 direct-acting oral anticoagulants (DOACs)-non-vitamin K antagonists-have become available for patients with AF: dabigatran, rivaroxaban, apixaban, and edoxaban. In addition to a comparable efficacy to warfarin in large randomized controlled trials, DOACs were found to promote a lower risk of intracranial bleeding. The strategic dosage and lack of need for periodic prothrombin-time testing make their use attractive, especially for primary or secondary prevention of stroke in older adults. Furthermore, among patients with AF presenting with acute coronary syndrome or undergoing percutaneous coronary intervention, apixaban is associated with a reduction in serious bleeding events when compared with warfarin. On the other hand, there is no evidence of benefit of DOACs in patients with mechanical prosthetic valves or moderate/severe mitral stenosis. Furthermore, the suitability of DOACs in patients with liver disease is still poorly understood, and their safety in patients requiring renal replacement therapy remains uncertain. This review provides an overview of the main trials of DOACs, their pharmacology and safety profile, clinical implications, and best indications in light of the current evidence.

The impact of underweight and obesity on outcomes in anticoagulated patients with atrial fibrillation: A systematic review and meta-analysis on the obesity paradox

Although obesity is associated with the development and progression of atrial fibrillation (AF), an obesity paradox may be present, illustrated by seemingly protective effects of obesity on AF-related outcomes. Body mass index (BMI) has an impact on outcomes in AF patients using oral anticoagulants. After searching Medline and Embase, meta-analysis of results of four randomized and five observational studies demonstrated significantly lower risks of stroke or systemic embolism (RR 0.80, 95%CI [0.73-0.87]; RR 0.63, 95%CI [0.57-0.70]; and RR 0.42, 95%CI [0.31-0.57], respectively) and all-cause mortality (RR 0.73, 95%CI [0.64-0.83]; RR 0.61, 95%CI [0.52-0.71]; and RR 0.56, 95%CI [0.47-0.66], respectively) in overweight, obese and morbidly obese anticoagulated AF patients (BMI 25 to <30, ≥30 and ≥40 kg/m2 , respectively) compared to normal BMI anticoagulated AF patients (BMI 18.5 to <25 kg/m2 ). In contrast, thromboembolic (RR 1.92, 95%CI [1.28-2.90]) and mortality (RR 3.57, 95%CI [2.50-5.11]) risks were significantly increased in underweight anticoagulated AF patients (BMI <18.5 kg/m2 ). In overweight and obese anticoagulated AF patients, the risks of major bleeding (RR 0.86, 95%CI [0.76-0.99]; and RR 0.88, 95%CI [0.79-0.98], respectively) and intracranial bleeding (RR 0.75, 95%CI [0.58-0.97]; and RR 0.57, 95%CI [0.40-0.80], respectively) were also significantly lower compared to normal BMI patients, while similar risks were observed in underweight and morbidly obese patients. This meta-analysis demonstrated lower thromboembolic and mortality risks with increasing BMI. However, as this paradox was driven by results from randomized studies, while observational studies rendered more conflicting results, these seemingly protective effects should still be interpreted with caution.

Assessment of non-vitamin K antagonist oral anticoagulants for the management of left ventricular thrombus

Although several studies have assessed the effect of non-vitamin K antagonist oral anticoagulants (NOACs) relative to that of vitamin K antagonists (VKAs) in patients with left ventricular thrombus, the results remain controversial. Herein, a meta-analysis was performed to compare the effectiveness and safety of NOACs versus VKAs for the treatment of left ventricular thrombus. We systematically searched the Cochrane Library, PubMed and Embase databases until November 2020 for studies that compared the effects of NOACs versus VKAs in patients with left ventricular thrombus. The treatment effects were expressed as odds ratios (ORs) with 95% confidence intervals (CIs) and pooled by a random-effects model. Seven retrospective studies involving 865 patients with left ventricular thrombus (266 NOAC and 599 VKA users) were included. The pooled analysis suggested no difference in the rate of thrombus resolution between the NOAC and VKA groups (OR = 0.83, 95% CI 0.61-1.13). There were also no differences in the rates of stroke or systemic embolism (OR = 0.62, 95% CI 0.20-1.97), bleeding events (OR = 0.73, 95% CI 0.37-1.45), or all-cause death (OR = 0.92, 95% CI 0.50-1.69) between patients treated with NOACs and those treated with VKAs. In addition, the rates of thrombus resolution, stroke or systemic embolism, bleeding events, and all-cause death between NOAC- and warfarin-treated patients were also similar. Our current evidence suggested that NOAC and VKA users had similar rates of thrombus resolution and clinical outcomes among patients with left ventricular thrombus. Further large-scale prospective studies should confirm our results.

Meta-analysis of type 1 diabetes mellitus and risk of cardiovascular disease

BACKGROUND

Individuals with diabetes have a high risk of cardiovascular disease (CVD). However, the association between type 1 diabetes mellitus (T1DM) and the risk of CVD has not been well addressed. This meta-analysis aimed to investigate the association between T1DM and CVD.

METHODS

We searched the PubMed and EMBASE for studies that examined the association between T1DM and CVD until October 2020. We calculated the pooled risk ratios (RRs) with confidence intervals (CIs) from individual studies based on a random-effects model.

RESULTS

We included 10 observational studies involving 166,027 patients with T1DM, and individuals were matched controls from the general population. Among T1DM patients, the RR of CVD was 5.09 (95% CI, 3.72-6.96), of coronary heart disease (CHD) was 9.38 (95% CI, 5.56-15.82), and of myocardial infarction was 6.37 (95% CI, 3.81-10.66). The RR of heart failure was 4.29 (95% CI, 3.54-5.19), of atrial fibrillation was 1.36 (95% CI, 1.17-1.59), and of stroke was 4.08 (95% CI, 3.42-4.86). Moreover, there was an increased RR among females for CHD, CVD, myocardial infarction, and stroke associated with T1DM.

CONCLUSIONS

This study suggests that T1DM is associated with an increased risk of several types of CVD. However, the possible mechanisms for the increased risk of CVD remain unclear.

Outcomes of Direct Oral Anticoagulants in Atrial Fibrillation Patients Across Different Body Mass Index Categories

OBJECTIVES

This study sought to evaluate direct oral anticoagulant (DOAC) outcomes (vs. warfarin) in patients with atrial fibrillation (AF) across body mass index (BMI) categories, including ≥40 and <18.5 kg/m².

BACKGROUND

Clinical trials have not systematically tested the fixed DOAC dosing in underweight and morbidly obese patients.

METHODS

We retrospectively included consecutive patients with nonvalvular AF with CHA₂DS₂-VASc (Congestive heart failure, Hypertension, Age ≥75, Diabetes, Stroke/transient ischemic attack/systemic thromboembolism, Vascular disease, Age 65-74, Sex) of ≥1 receiving OACs at our hospital system (2010-2018). Patients were categorized into groups 1 (underweight: BMI of <18.5 kg/m²), 2 (normal/overweight: BMI of 18.5 to <30 kg/m²), 3 (grade 1/2 obesity: BMI of 30 to <40 kg/m²), and 4 (grade 3 obesity: BMI of ≥40 kg/m²). We further classified patients by DOAC versus warfarin use. Outcomes were ischemic stroke, significant bleeding events (i.e., resulting in hospitalization), and mortality.

RESULTS

We included 36,094 patients with a mean age of 74 ± 11 years and CHA₂DS₂-VASc of 3.4 ± 1.5. Groups 1 through 4 included 455 (1.3%), 18,339 (50.8%), 13,376 (37.1%), and 3,924 (10.9%) patients, respectively. DOAC use ranged from 49% to 56%. At 3.8 follow-up years, with multivariable Cox regression, DOACs (vs. warfarin) were associated with lower risk of ischemic stroke, bleeding, and mortality across all BMI groups, with hazard ratios (HRs) of 0.73 (95% confidence interval [CI]: 0.63 to 0.85), 0.75 (95% CI: 0.64 to 0.87), 0.75 (95% CI: 0.65 to 0.88), and 0.75 (95% CI: 0.64 to 0.87) (p < 0.001 for all) for ischemic stroke; 0.42 (95% CI: 0.19 to 0.92), 0.41 (95% CI: 0.19 to 0.89), 0.45 (95% CI: 0.20 to 1.00), and 0.43 (95% CI: 0.20 to 0.94) (p < 0.05 for all) for bleeding; and 0.90 (95% CI: 0.68 to 1.19; p = 0.5), 0.70 (95% CI: 0.66 to 0.75; p < 0.0001), 0.65 (95% CI: 0.60 to 0.71; p < 0.0001), and 0.66 (95% CI: 0.56 to 0.77; p < 0.0001) for mortality, in groups 1 to 4, respectively.

CONCLUSIONS

In patients with nonvalvular AF, DOACs compared to warfarin were associated with better safety and effectiveness across all BMI categories, including underweight and morbidly obese patients.

Safety and Efficacy of Rivaroxaban and Apixaban in Patients with Increased Body Mass: a Systematic Review

BACKGROUND AND OBJECTIVE

Rivaroxaban and apixaban are direct oral anticoagulants increasing in popularity as convenient alternatives to warfarin. However, current guidelines recommend against use in patients with a BMI > 40 kg/m² or bodyweight > 120 kg unless drug-specific levels are measured, which may not be feasible across all clinical practices. Accordingly, the objective of this study was to broadly examine literature evaluating the clinical outcomes of rivaroxaban and/or apixaban in patients with increased body mass.

METHODS

A systematic literature review (guided by PRISMA) was performed through January 27, 2021 using PubMed, Embase, and Scopus. Key search term clusters included drug and weight-related concepts (overweight/obese, body mass index [BMI], waist circumference). DistillerSR was utilized to review and process search results. Studies met inclusion if they analyzed the risk of bleeding and/or thrombosis in patients with increased body mass (i.e., via BMI or other criteria) receiving rivaroxaban or apixaban. Clinical guidelines, case reports/series, pharmacokinetic/dynamic analyses, and commentaries were excluded. Bias was examined qualitatively across studies.

RESULTS

After duplicates were removed, the original search rendered 1822 abstracts and 200 full-texts for screening, ultimately providing a final set of 24 studies for qualitative review. Of these studies, 13 (54.2%) enabled comparisons between patients of increased versus normal body mass, while 11 (45.8%) reported outcomes only for patients of increased body mass. The working definition of 'increased body mass' varied amongst the studies, including 11 (45.8%) studies that utilized BMI, seven (29.2%) with a combination of BMI and body measurement, two (8.3%) that relied on body weight alone, and four (16.7%) that identified obesity-related ICD codes. All 13 comparative studies found similar or reduced rates of safety and efficacy outcomes with rivaroxaban and apixaban.

CONCLUSION

The literature reports similar or lower bleeding and thrombotic risk for rivaroxaban and apixaban in patients of increased body mass compared to patients of normal body mass. Future prospective controlled studies are needed to further define guidelines for use in this population.

Effect of non-recommended doses versus recommended doses of direct oral anticoagulants in atrial fibrillation patients: A meta-analysis

Background

Several observational studies have shown that the inappropriate dosing use of direct oral anticoagulants (DOACs) in atrial fibrillation (AF) that does not conform to recommendations is becoming a widespread phenomenon. Therefore, we performed a meta‐analysis and systematic review to assess the effect of non‐recommended doses versus recommended doses of DOACs on the effectiveness and safety outcomes among AF patients.

Methods

The PubMed and Ovid databases were systematically searched to identify the relevant studies until December 2020. The effect estimates were hazard ratios (HRs) and 95% confidence intervals (CIs), which were pooled using a fixed‐effects model (I² ≤ 50%) or a random‐effects model (I² > 50%).

Results

A total of 11 studies were included in this meta‐analysis. Compared with recommended dosing of DOACs, non‐recommended low dosing of DOACs was associated with increased risks of stroke or systemic embolism (SSE, HR = 1.29, 95% CI 1.12–1.49) and all‐cause death (HR = 1.37, 95% CI 1.15–1.62), but not the ischemic stroke, myocardial infarction, gastrointestinal bleeding, intracranial bleeding, and major bleeding. Compared with recommended dosing of DOACs, non‐recommended high dosing of DOACs was associated with increased risks of SSE (HR = 1.44, 95% CI 1.01–2.04), major bleeding (HR = 1.99, 95% CI 1.48–2.68), and all‐cause death(HR = 1.38, 95% CI 1.02–1.87).

Conclusion

Compared with recommended dosing of DOACs, non‐recommended low dosing of DOACs was associated with increased risks of SSE and all‐cause death. Further study should confirm the findings of non‐recommended high dosing versus recommended dosing of DOACs.

Comparative Effectiveness and Safety of Non-Vitamin K Antagonist Oral Anticoagulants in Atrial Fibrillation Patients

BACKGROUND AND PURPOSE

Several observational studies have compared the effect of the non-vitamin K antagonist oral anticoagulants to each other in patients with atrial fibrillation. However, confounding by indication is a major problem when comparing non-vitamin K antagonist oral anticoagulant treatments in some of these studies. This meta-analysis was conducted to compare the effectiveness and safety between non-vitamin K antagonist oral anticoagulant and non-vitamin K antagonist oral anticoagulant by only including the propensity score matching studies.

METHODS

We systematically searched the PubMed and Ovid databases until May 2020 to identify relevant observational studies. Hazard ratios (HRs) and 95% CIs of the reported outcomes were collected and then pooled by a random-effects model complemented with an inverse variance heterogeneity or quality effects model.

RESULTS

A total of 17 retrospective cohort studies were included in this meta-analysis. Compared with dabigatran use, the use of rivaroxaban was significantly associated with increased risks of stroke or systemic embolism (HR, 1.16 [95% CI, 1.05-1.29]) and major bleeding (HR, 1.32 [95% CI, 1.24-1.41]), whereas the use of apixaban was associated with a reduced risk of major bleeding (HR, 0.78 [95% CI, 0.67-0.90]) but not stroke or systemic embolism (HR, 0.84 [95% CI, 0.56-1.28]). Compared with rivaroxaban use, the use of apixaban was associated with a decreased risk of major bleeding (HR, 0.63 [95% CI, 0.54-0.73]) but not stroke or systemic embolism (HR, 0.83 [95% CI, 0.67-1.04]). Reanalyses with the inverse variance heterogeneity or quality effects model produced similar results as the random-effects model.

CONCLUSIONS

Current observational comparisons with propensity score matching methods suggest that apixaban might be a better choice compared with dabigatran or rivaroxaban for stroke prevention in atrial fibrillation patients.

Meta-analysis of metabolic syndrome and its individual components with risk of atrial fibrillation in different populations

Background

Recent studies have reported the effects of metabolic syndrome (MetS) and its components on atrial fibrillation (AF), but the results remain controversial. Therefore, we performed a meta-analysis to evaluate the relationship between MetS and AF risk.

Methods

Studies were searched from the Cochrane library, PubMed, and Embase databases through May 2020. Adjusted hazard ratios (HRs) and its corresponding 95% confidence intervals (CIs) were extracted and then pooled by using a random effects model.

Results

A total of 6 observational cohort studies were finally included. In the pooled analysis, MetS was associated with an increased risk of AF (HR 1.57; 95% CI 1.40–1.77; P < 0.01). And the components of MetS including abdominal obesity (HR 1.37; 95% CI 1.36–1.38; P < 0.01), elevated blood pressure (HR 1.56; 95% CI 1.46–1.66; P < 0.01), elevated fasting glucose (HR 1.18; 95% CI 1.15–1.21; P < 0.01) and low high density cholesterol (HDL) (HR 1.18; 95% CI 1.06–1.32; P < 0.01) was also associated with an increased risk of AF, while high triglyceride (HR 0.99; 95% CI 0.87–1.11, P = 0.82) was not.

Conclusions

Our present meta-analysis suggested that MetS, as well as its components including abdominal obesity, elevated blood pressure, elevated fasting glucose and low HDL cholesterol were associated with an increase in the risk of AF.

A review of indications and comorbidities in which warfarin may be the preferred oral anticoagulant

WHAT IS KNOWN AND OBJECTIVE

Direct oral anticoagulants (DOACs) are increasingly prescribed instead of warfarin for chronic anticoagulation for ease of dosing, fewer interactions, and less stringent monitoring. However, it is important to consider indications and comorbidities for which warfarin is still the preferred anticoagulant. This review aims to capture these clinical scenarios in which warfarin may still be preferred over DOACs.

METHODS

We undertook a comprehensive literature search using the PubMed database. Key search terms were based on DOAC clinical trial exclusion criteria, as well as indications and conditions in which the use of DOACs for anticoagulation has suggested harm. Society guidelines and tertiary literature were used to inform expert opinion where necessary. Studies were included if they investigated the use of DOACs or warfarin in the identified indications or conditions.

RESULTS AND DISCUSSION

Currently, evidence for the use of warfarin over DOACs for anticoagulation is strongest for patients with prosthetic valves, antiphospholipid syndrome, or a high risk of gastrointestinal bleeding. For several clinical situations, including mitral stenosis, obesity, altered gastrointestinal anatomy, pulmonary arterial hypertension, renal or hepatic impairment, and left ventricular thrombus, evidence is lacking but may eventually support the use of DOACs. Depending on indication and condition, appropriateness of DOAC use may vary by agent.

WHAT IS NEW AND CONCLUSION

New evidence continues to support new indications and conditions in which DOACs may be appropriate to use for anticoagulation. There are key clinical scenarios, however, in which emerging literature continues to support warfarin as the preferred anticoagulant.

Use of direct-acting oral anticoagulants in solid organ transplantation: A systematic review

The use of direct-acting oral anticoagulants (DOACs) has increased secondary to the mounting evidence for comparable efficacy and potentially superior safety to vitamin K antagonists (VKAs) in the general population. However, insufficient data regarding DOAC use in solid organ transplant (SOT) recipients and numerous pharmacokinetic and pharmacodynamic considerations limit their use in this highly selected patient population. A systematic review of recent clinical evidence on the safety and efficacy of DOACs compared to VKAs in SOT recipients was conducted. Additional considerations including transplant-specific strategies for DOAC reversal and common pharmacokinetic/pharmacodynamic concerns were also reviewed. Although current evidence is limited to single-center retrospective analyses, DOACs, especially apixaban, appear to be a safe and effective alternative to VKAs for SOT recipients with stable graft function and without drug-drug interactions. Reliable data on DOAC reversal at the time of transplant surgery are lacking, and clinicians should consider idarucizumab, andexanet alfa, and other non-specific reversal agents on an individual patient basis. There is no evidence supporting deviations from the Food and Drug Administration labeling recommendations for DOAC dosing in the setting of drug-drug interactions, obesity, and renal function, especially in patients on hemodialysis.

Dosage of Anticoagulants in Obesity: Recommendations Based on a Systematic Review

Anticoagulants are frequently used as thromboprophylaxis and in patients with atrial fibrillation (AF) or venous thromboembolism (VTE). While obesity rates are reaching epidemic proportions worldwide, the optimal dosage for obese patients has not been established for most anticoagulants, including low-molecular-weight heparin (LMWH), non-vitamin K antagonist oral anticoagulants (NOAC), and pentasaccharides (fondaparinux). The aim of the present systematic review was to summarize the current knowledge and provide recommendations on dosage of LMWH, NOAC, and fondaparinux in obese patients (body mass index [BMI] ≥ 30 kg/m² or body weight ≥ 100 kg). Based on a systematic search in PubMed and Embase, a total of 72 studies were identified. For thromboprophylaxis with LMWH in bariatric surgery (n = 20 studies), enoxaparin 40 mg twice daily, dalteparin 5,000 IE twice daily, or tinzaparin 75 IU/kg once daily should be considered for patients with BMI ≥ 40 kg/m². For thromboprophylaxis with LMWH in nonbariatric surgery and in medical inpatients (n = 8 studies), enoxaparin 0.5 mg/kg once or twice daily or tinzaparin 75 IU/kg once daily may be considered in obese patients. For treatment with LMWH (n = 18 studies), a reduced weight-based dose of enoxaparin 0.8 mg/kg twice daily should be considered in patients with BMI ≥ 40 kg/m², and no dose capping of dalteparin and tinzaparin should be applied for body weight < 140 kg. As regards NOAC, rivaroxaban, apixaban, or dabigatran may be used as thromboprophylaxis in patients with BMI < 40 kg/m² (n = 4 studies), whereas rivaroxaban and apixaban may be administered to obese patients with VTE or AF, including BMI > 40 kg/m², at standard fixed-dose (n = 20 studies). The limited available evidence on fondaparinux (n = 3 studies) indicated that the treatment dose should be increased to 10 mg once daily in patients weighing > 100 kg.

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.

Direct oral anticoagulants in the treatment of acute venous thromboembolism in patients with obesity: A systematic review with meta-analysis

BACKGROUND

Direct oral anticoagulants' (DOAC) pharmacokinetics are affected by obesity. Their efficacy and safety in obesity (BMI≥30 kg/m²) and morbid obesity (BMI≥40 kg/m²) are still unclear in the treatment of venous thromboembolism (VTE).

OBJECTIVES

To compare the efficacy/safety of DOAC versus vitamin K antagonist (VKA)/low molecular weight heparin (LMWH) for the treatment of VTE in patients with obesity and morbid obesity. The primary efficacy/safety outcomes were VTE recurrence and major bleeding (MB). Clinically relevant non-MB and mortality were also evaluated.

METHODS

A systematic literature search (MEDLINE, EMBASE, CENTRAL, Web of Science) identified studies evaluating DOAC in the treatment of VTE in patients with obesity and reporting one of the outcomes. Relative risks (RR) and 95 % confidence intervals (CI) were estimated using the Mantel-Haenszel method.

RESULTS

We included 21 studies (50,360pts) of which 16,150 patients had a BMI≥30 kg/m² and 6443 patients had a BMI≥40 kg/m². VTE recurrence was similar with DOAC compared to VKA/LMWH in patients with obesity (RR 1.03;95 %CI 0.93-1.15;p = 0.55) and morbid obesity (RR 1.06;95 %CI 0.94-1.19;p = 0.35). DOAC were also associated with a reduction in MB (RR 0.57;95 %CI 0.34-0.94;p = 0.03 and RR 0.71;95 %CI 0.50-1.00;p = 0.05 in patients with obesity and morbid obesity, respectively). Subgroup analyses comparing randomized controlled trials to observational studies showed consistent results. No difference was observed in regards of clinically relevant non-MB and mortality.

CONCLUSION

There is no signal for differences in VTE recurrence in patients with obesity and morbid obesity treated with DOAC compared to VKA/LMWH, while DOAC likely reduce the risk of MB compared to VKA/LMWH.

Non-Vitamin K Antagonist Oral Anticoagulant for Atrial Fibrillation in Obese Patients

Four non-vitamin K antagonist oral anticoagulants (NOACs) are approved for use to reduce the risk of stroke and systemic embolism in patients with atrial fibrillation (AF). However, data are limited regarding the use of NOACs in the obese population. This manuscript summarizes current concepts regarding obesity in patients with AF and reviews in depth the data on the efficacy and safety of NOACs in obese patients with AF. The Pubmed database was searched for relevant articles. When evaluating obese patients with AF, weight loss is important to reduce disease burden. Recent analyses of the four NOAC versus warfarin trials (RE-LY, ROCKET-AF, ARISTOTLE, and ENGAGE AF-TIMI 48) stratified by body mass index (BMI) demonstrate preserved efficacy with NOACs versus warfarin in obese patients, with similar risk of major bleeding. Although the data are limited in class III obese patients (body mass index ≥40kg/m²), the efficacy and safety of apixaban or edoxaban appears to be similar to warfarin in patients with BMI 40-50kg/m². In conclusion, these new data should be considered in updated guidelines, which currently provide limited, and sometimes conflicting recommendations regarding the use of NOACs in obese patients, particularly in severely obese patients.