Direct Oral Anticoagulants in Asian Patients with Atrial Fibrillation: Consensus Recommendations by the Asian Pacific Society of Cardiology on Strategies for Thrombotic and Bleeding Risk Management

Role of anticoagulation in non-ST-elevation myocardial infarction: a contemporary narrative review

INTRODUCTION

Anticoagulants play a vital role as part of the antithrombotic therapy of myocardial infarction and are complementary to antiplatelet therapies. In the acute setting, the rationale for their use is to antagonize the ongoing clotting cascade including during percutaneous coronary intervention. Anticoagulation may be an important part of the longer-term antithrombotic strategy especially in patients who have other existing indications (e.g. atrial fibrillation) for their use.

AREAS COVERED

In this narrative review, the authors provide a contemporary summary of the anticoagulation strategies of patients presenting with NSTEMI, both in terms of anticoagulation during the acute phase as well as suggested antithrombotic regimens for patients who require long-term anticoagulation for other indications.

EXPERT OPINION

Patients presenting with non-ST-elevation myocardial infarction (NSTEMI) should be initiated on anticoagulation (e.g. heparin/low molecular weight heparin) for the initial hospitalization period for those medically managed or until percutaneous coronary intervention. Longer term management of NSTEMI for patients with an existing indication for long-term anticoagulation should comprise triple antithrombotic therapy of anticoagulant (preferably DOAC) with aspirin and clopidogrel for up to 1 month (typically 1 week or until hospital discharge), followed by DOAC plus clopidogrel for up to 1 year, and then DOAC monotherapy thereafter.

Establishment and Validation of the Nomogram Model and the Probability of Silent Cerebral Infarction After Ablation Atrial Fibrillation

BACKGROUND

The objective of this study is to establish and validate a nomogram model for predicting the probability of silent cerebral infarction following ablation of atrial fibrillation.

METHODS AND RESULTS

A retrospective observational study was conducted on the data of 238 patients with atrial fibrillation who underwent radiofrequency ablation in our hospital from October 2019 to December 2022. LASSO regression and multivariate logistics regression analysis were used to assess the independent risk factors for silent cerebral infarction after ablation. The AUC of the predictive model was 0.733 (95% CI, 0.649-0.816) and the internal validation (bootstrap = 1000) of the bootstrap method was 0.733 (95% CI 0.646-0.813). The Hosmer-Lemeshow test yields an insignificant p-value of X-squared = 10.212 and p-value = 0.2504, thus indicating an insignificant difference between predicted and observed values and good calibration results. The clinical impact curve (CIC) and clinical decision curve also prove that this graph is useful in the clinical setting.

CONCLUSION

We developed an easy-to-use nomogram model to predict the probability of silent cerebral infarction following radiofrequency ablation of atrial fibrillation. This model can provide a valid assessment of the probability of postoperative silent cerebral infarction in patients undergoing radiofrequency ablation of atrial fibrillation.

Early experiences with edoxaban for stroke prevention in atrial fibrillation in the Southeast Asia region

Edoxaban, a once-daily, direct-acting oral anticoagulant, is approved to prevent stroke or systemic embolism in non-valvular atrial fibrillation (NVAF) and treat venous thromboembolism. The clinical benefit of edoxaban for stroke prevention in Asian patients with NVAF has been demonstrated in clinical and real-world studies. We share early clinical experiences with once-daily edoxaban and discuss its evidence-based use in patients with NVAF in Southeast Asia through several cases of patients at high risk, including frail patients, elderly patients with multiple comorbidities and patients with increased bleeding risk. These cases demonstrate the effectiveness and safety of once-daily edoxaban in patients with NVAF in Southeast Asia.

A nomogram for predicting major gastrointestinal bleeding in patients treated with rivaroxaban

BACKGROUND

Rivaroxaban is a direct oral anticoagulant with the highest risk of anticoagulant-induced major gastrointestinal bleeding (MGIB). Currently, there is a lack of tools to identify patients at high risk of rivaroxaban-induced MGIB.

OBJECTIVE

To establish a nomogram model to predict the risk of MGIB in patients receiving rivaroxaban.

METHODS

Demographic information, comorbidities, concomitant medications, and laboratory test results were collected from 356 patients (178 diagnosed with MGIB) who were taking rivaroxaban between January 2013 and June 2021. Univariate and multivariate logistic regression analyses were used to identify the independent predictors of MGIB, and a nomogram was constructed based on these predictors. A receiver operating characteristic curve, Brier score, calibration plot, decision curve, and internal validation was used to evaluate the calibration, discrimination, and clinical usefulness of the nomogram.

RESULTS

Age, haemoglobin level, platelet count, creatinine level, prior peptic ulcer disease, prior bleeding, prior stroke, proton pump inhibitor use, and antiplatelet agent use were independent predictors of rivaroxaban-induced MGIB. These risk factors were used to establish the nomogram. The area under the curve of the nomogram was 0.833 (95%CI, 0.782-0.866), the Brier score was 0.171, the internal validation accuracy was 0.73, and the kappa value was 0.46.

CONCLUSION

The nomogram demonstrated good discrimination, calibration, and clinical applicability. Therefore, it could accurately predict the risk of MGIB in patients treated with rivaroxaban.

First-in-human trial of SAR107375E, a novel small molecule anticoagulant with dual inhibition of factor Xa and factor IIa

BACKGROUND

SAR107375E is a direct dual inhibitor of both Factor Xa and Factor IIa and has shown potent anticoagulation activity in vitro and animals. This study evaluated the safety, tolerability, pharmacokinetics, and pharmacodynamics of single ascending intravenous doses of SAR107375E in healthy Chinese adult subjects.

METHODS

In this randomized, double-blind, placebo-controlled trial, 60 healthy Chinese adult subjects were administered intravenously single ascending doses (0.5, 1.5, 3.0, 5.0, 7.5, 10.0, 15.0, or 20.0 mg) of SAR107375E (N = 44) or placebo (N = 16). Plasma and urine concentrations of SAR107375E were measured and used to calculate pharmacokinetic parameters. Coagulation functions were measured and compared with baseline values. Treatment-emergent adverse events were recorded to evaluate safety.

RESULTS

In plasma, from the 0.5 to 20.0 mg dose group, t1/2 is 1.51-4.00 h, Cmax is 59.05-1360 ug/L, and AUC0-t is 25.01-528.45 h*ug/L. And it shows dose proportionality in the 5.0-20.0 mg range. Activated partial thromboplastin time and Ecarin clotting time correlated linearly with drug plasma concentration. No serious adverse events were reported during the study.

CONCLUSION

SAR107375E exhibits good safety and tolerability, predictable pharmacokinetics and pharmacodynamics.

CLINICAL TRIAL REGISTRATION

www.chinadrugtrials.org.cn, identifier is CTR20211082.

Phenotype-directed clinically driven low-dose direct oral anticoagulant for atrial fibrillation

Clinically-driven dose reduction of direct oral anticoagulants in individuals with atrial fibrillation is prevalent worldwide. However, a paucity of evidence to tailor dose selection remained as clinical unmet need. Current doses of anticoagulant were determined largely by landmark clinical trials, in which the enrolled subjects were carefully selected and without major comorbidities. Our study reviewed the relevant real-world studies in specific patient phenotypes, including renal and hepatic diseases, elderly, low body weight, Asians and presence of concomitant drug-drug interactions. Thorough investigations toward the efficacy and safety of direct oral anticoagulants in reduced doses will facilitate substituting current universal approach with individualized prescriptions.

Comparative Effectiveness and Safety of Direct Oral Anticoagulants and Warfarin in Patients With Atrial Fibrillation and Chronic Liver Disease: A Nationwide Cohort Study

BACKGROUND

The benefit-risk profile of direct oral anticoagulants (DOACs) compared with warfarin, and between DOACs in patients with atrial fibrillation (AF) and chronic liver disease is unclear.

METHODS

We conducted a new-user, retrospective cohort study of patients with AF and chronic liver disease who were enrolled in a large, US-based administrative database between January 1, 2011, and December 31, 2017. We assessed the effectiveness and safety of DOACs (as a class and individually) compared with warfarin, and between DOACs in patients with AF and chronic liver disease. The primary outcomes were hospitalization for ischemic stroke/systemic embolism and hospitalization for major bleeding. Inverse probability treatment weights were used to balance the treatment groups on measured confounders.

RESULTS

Overall, 10 209 participants were included, with 4421 (43.2%) on warfarin, 2721 (26.7%) apixaban, 2211 (21.7%) rivaroxaban, and 851 (8.3%) dabigatran. The incidence rates per 100 person-years for ischemic stroke/systemic embolism were 2.2, 1.4, 2.6, and 4.4 for DOACs as a class, apixaban, rivaroxaban, and warfarin, respectively. The incidence rates per 100 person-years for major bleeding were 7.9, 6.5, 9.1, and 15.0 for DOACs as a class, apixaban, rivaroxaban, and warfarin, respectively. After inverse probability treatment weights, the risk of hospitalization for ischemic stroke/systemic embolism was significantly lower between DOACs as a class (hazard ratio [HR], 0.64 [95% CI, 0.46-0.90]) or apixaban (HR, 0.40 [95% CI, 0.19-0.82]) compared with warfarin, but not significantly different between rivaroxaban versus warfarin (HR, 0.76 [95% CI, 0.47-1.21]) or rivaroxaban versus apixaban (HR, 1.73 [95% CI, 0.91-3.29]). Compared with warfarin, the risk of hospitalization for major bleeding was lower with DOACs as a class (HR, 0.69 [95% CI, 0.58-0.82]), apixaban (HR, 0.60 [95% CI, 0.46-0.78]), and rivaroxaban (HR, 0.79 [95% CI, 0.62-1.0]). However, the risk of hospitalization for major bleeding was higher for rivaroxaban versus apixaban (HR, 1.59 [95% CI, 1.18-2.14]).

CONCLUSIONS

Among patients with AF and chronic liver disease, DOACs as a class were associated with lower risks of hospitalization for ischemic stroke/systemic embolism and major bleeding versus warfarin. However, the incidence of clinical outcomes among patients with AF and chronic liver disease varied between individual DOACs and warfarin, and in head-to-head DOAC comparisons.

Bidirectional effects of oral anticoagulants on gut microbiota in patients with atrial fibrillation

Background

The imbalance of gut microbiota (GM) is associated with a higher risk of thrombosis in patients with atrial fibrillation (AF). Oral anticoagulants (OACs) have been found to significantly reduce the risk of thromboembolism and increase the risk of bleeding. However, the OAC-induced alterations in gut microbiota in patients with AF remain elusive.

Methods

In this study, the microbial composition in 42 AF patients who received long-term OAC treatment (AF-OAC group), 47 AF patients who did not (AF group), and 40 volunteers with the risk of AF (control group) were analyzed by 16S rRNA gene sequencing of fecal bacterial DNA. The metagenomic functional prediction of major bacterial taxa was performed using the Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) software package.

Results

The gut microbiota differed between the AF-OAC and AF groups. The abundance of Bifidobacterium and Lactobacillus decreased in the two disease groups at the genus level, but OACs treatment mitigated the decreasing tendency and increased beneficial bacterial genera, such as Megamonas. In addition, OACs reduced the abundance of pro-inflammatory taxa on the genus Ruminococcus but increased certain potential pathogenic taxa, such as genera Streptococcus, Escherichia-Shigella, and Klebsiella. The Subgroup Linear discriminant analysis effect size (LEfSe) analyses revealed that Bacteroidetes, Brucella, and Ochrobactrum were more abundant in the anticoagulated bleeding AF patients, Akkermansia and Faecalibacterium were more abundant in the non-anticoagulated-bleeding-AF patients. The neutrophil-to-lymphocyte ratio (NLR) was lower in the AF-OAC group compared with the AF group (P < 0.05). Ruminococcus was positively correlated with the NLR and negatively correlated with the CHA2DS2-VASc score (P < 0.05), and the OACs-enriched species (Megamonas and Actinobacteria) was positively correlated with the prothrombin time (PT) (P < 0.05). Ruminococcus and Roseburia were negatively associated with bleeding events (P < 0.05).

Conclusions

Our study suggested that OACs might benefit AF patients by reducing the inflammatory response and modulating the composition and abundance of gut microbiota. In particular, OACs increased the abundance of some gut microbiota involved in bleeding and gastrointestinal dysfunction indicating that the exogenous supplementation with Faecalibacterium and Akkermansia might be a prophylactic strategy for AF-OAC patients to lower the risk of bleeding after anticoagulation.

Thrombosis and anticoagulation: clinical issues of special importance to hematologists who practice in Asia

There are clinical issues of special importance and practice variation in the management of venous thromboembolism (VTE) and in the use of anticoagulants among hematologists who practice in Asia. In Asian-inherited thrombophilia, coagulation is disturbed due to loss-of-function mutations of protein S and protein C causing protein S and protein C deficiencies, whereas the gain-of-function factor V Leiden and prothrombin G20210A mutations are almost absent. Thrombophilia screening is not recommended in patients with VTE patients who have major provoking factors. However, it can be considered in unprovoked young patients with VTE who have a strong family history of VTE. Cancer is the most important acquired risk factor for VTE in Asians. Limited cancer screening at the initial presentation of unprovoked VTE is appropriate, especially in the elderly. Direct oral anticoagulants have been shown to have similar efficacy and reduce risk of major bleeding, including intracranial hemorrhage and bleeding requiring hospitalization, compared with warfarin. Most clinical trials evaluating therapies for treatment and prevention of VTE have included small numbers of Asian patients. Despite this lack of evidence, direct oral anticoagulants have been increasingly used in Asia for cancer-associated thrombosis. Individualized assessment of thrombotic and bleeding risks should be used for all hospitalized Asian patients when deciding on pharmacologic thromboprophylaxis. More research is needed to understand the factors that contribute to risks of VTE and anticoagulant-associated bleeding in Asian patients as these may differ from Western populations.

Effectiveness and Safety of Reduced and Standard Daily Doses of Direct Oral Anticoagulants in Patients with Nonvalvular Atrial Fibrillation: A Cohort Study Using National Database Representing the Japanese Population

Purpose

To compare the effectiveness and safety of reduced or standard daily doses of direct oral anticoagulants (DOACs) with warfarin in Japanese patients with nonvalvular atrial fibrillation (NVAF). We used post-hoc analyses to identify patient groups that could benefit from reduced-dose DOACs.

Patients and Methods

Using the National Database of Health Insurance Claims and Specific Health Checkups of Japan, we identified 944,776 patients with NVAF who had started an oral anticoagulant after at least one year of non-use between April 2011 and March 2016. We matched patients taking any, reduced, or standard doses of DOACs 1:1 with those taking warfarin. We measured treatment effectiveness based on admission due to stroke or systemic embolism (S/SE) and safety based on admission due to any bleeding (defined as major bleeding, MB). We compared both outcomes between DOACs and warfarin using the Cox proportional hazards model. We used post-hoc analysis to match patients receiving reduced-dose DOACs to those receiving standard-dose DOACs and compared treatment effectiveness and safety.

Results

More than half of patients receiving DOACs used a reduced dose. The occurrences of S/SE and MB in patients receiving any, reduced, or standard doses of DOACs were equal to or lower than those receiving warfarin. In the post-hoc analysis, the risk of S/SE and MB was similar between reduced and standard doses of DOACs except for those with a history of cerebral infarction and CHA₂DS₂-VASc score ≥3, where the risk of S/SE was lower for reduced doses of any and individual DOACs.

Conclusion

Findings from the current study are consistent with recent Asian and global studies but different from most studies conducted in North America and Europe, where patients receiving a reduced dose of DOACs had an increased risk of S/SE. Future studies should test the reproducibility of results from the current study.

Alcohol consumption in relation to the incidence of atrial fibrillation in an elderly Chinese population

BACKGROUND

Alcohol consumption is a known modifiable risk factor for atrial fibrillation. The association, however, might differ according to gender. We investigated gender-specific associations between alcohol consumption and incident atrial fibrillation in an elderly Chinese population.

METHODS

Our study participants were elderly residents (≥ 65 years) recruited from five community health centers in the urban area of Shanghai (n = 6,618). Alcohol intake was classified as never drinkers and current light-to-moderate (< 40 g/day) and heavy drinkers (≥ 40 g/day). Atrial fibrillation was detected by a 30-s single-lead electrocardiography (ECG, AliveCor^® Heart Monitor) and further evaluated with a regular 12-lead ECG.

RESULTS

During a median of 2.1 years (interquartile range: 2.0-2.2) follow-up, the incidence rate of atrial fibrillation was 1.10% in all study participants. It was slightly but non-significantly higher in men (n = 2849) than women (n = 3769, 1.30% vs. 0.96%, P = 0.19) and in current drinkers (n = 793) than never drinkers (n = 5825, 1.64% vs. 1.03%,P = 0.12). In both unadjusted and adjusted analyses, there was interaction between sex and current alcohol intake in relation to the incidence of atrial fibrillation (P < 0.0001). After adjustment for confounding factors, current drinkers had a significantly higher incidence rate of atrial fibrillation than never drinkers in women (12.96% [7/54] vs. 0.78% [29/3715], adjusted odds ratio [OR] = 10.25, 95% confidence interval [CI]: 3.54-29.67,P < 0.0001), but not in men (0.81% [6/739] vs. 1.47% [31/2110], OR = 0.62, 95% CI: 0.25-1.51,P = 0.29).

CONCLUSIONS

Our study showed a significant association between alcohol intake and the incidence of atrial fibrillation in elderly Chinese women, but not men.

Prevention of nNon-Vitamin K Oral Anticoagulants-Related Gastrointestinal Bleeding With Acid Suppressants: A Systematic Review and Meta-Analysis

Whether the use of acid suppressants can reduce non-vitamin K oral anticoagulants (NOACs)-related gastrointestinal bleeding (GIB) remains unclear. To systemically evaluate the effect of acid suppressants on the risk of GIB in patients treated with NOACs. All related studies were searched in four databases (Cochrane, Embase, PubMed, and Web of Science) from their establishment to August 10, 2021. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was used to identify studies and Stata 16.0 software was used for meta-analysis, including sensitivity and subgroup analysis. Six retrospective cohort studies were included in this study. The use of acid suppressants significantly reduced the GIB risk in patients taking NOACs, with an overall relative risk (RR) of 0.70 (95% confidence interval [CI]: 0.61-0.82; P < 0.001; I² = 56.3%). This trend of reduced risk for GIB in NOACs was more significant in upper GIB (UGIB; RR: 0.45; 95%CI: 0.22-0.90; P = 0.025; I² = 71.1%). The reduction was stronger for dabigatran than for rivaroxaban and apixaban. The least reduction in the risk of GIB with acid suppressant co-therapy was rivaroxaban (dabigatran: RR: 0.53; 95% CI: 0.45-0.62; P = <0.001; I² = 39.8%; apixaban: RR: 0.67; 95% CI: 0.54-0.84; P = <0.001; I² = 0; rivaroxaban: RR: 0.73; 95% CI: 0.66-0.81; P = <0.001; I² = 37.6%). The included studies revealed the protective effect of acid suppressants against NOACs-related GIB, especially in the upper gastrointestinal tract. The protective effect was even stronger in patients using dabigatran than in those using Xa inhibitors (rivaroxaban and apixaban).

Perceptions and knowledge gaps on CHA2DS2-VASc score components: a joint survey of Chinese clinicians and clinical pharmacists

BACKGROUND

The CHA₂DS₂-VASc score is a guideline-recommended stroke risk stratification scheme for patients with atrial fibrillation (AF). Accurately calculating the CHA₂DS₂-VASc score and recognizing the stroke risk in AF patients is the foundation of optimal anticoagulation therapy. This survey aims to obtain a comprehensive understanding of perceptions and knowledge gaps on CHA₂DS₂-VASc scores among Chinese medical professionals for future education programs.

METHODS

A cross-sectional survey was conducted among clinicians, including cardiologists, neurologists, emergency physicians (EPs), general practitioners (GPs) and clinical pharmacists (CPs) using a self-administered questionnaire on the Chinese mainland. The survey contained 21 questions in combination with single-choice questions, multiple-choice questions, and an open-ended question, which was distributed online via e-mail or social media.

RESULTS

A total of 562 participants (40.9% cardiologists, 19.2% neurologists, 8.5% EPs, 10.3% GPs, and 21.0% CPs) completed the survey. Most respondents across all specialties reported skills requiring improvements in the CHA₂DS₂-VASc score. In general, cardiologists, neurologists, and CPs had a relatively better understanding than GPs and EPs about the application of CHA₂DS₂-VASc score. Considering 'H' and 'D' components, more than 90% of respondents chose the correct answer in single-choice questions, whereas the correctness rate declined concerning detailed scoring criteria. Regarding 'C,' 'A₂,' 'S₂,' and 'V' components, partly correct answers were commonly observed in most multiple-choice questions. The majority of cardiologists believed themselves to be very familiar or at least familiar with the score and its components, while around 70% of EPs and GPs felt relatively unfamiliar with the CHA₂DS₂-VASc score. Mobile apps, AF guidelines and notebooks/handbooks were popular referencing scoring tools for respondents.

CONCLUSIONS

Chinese medical professionals, especially EPs and GPs, revealed a lack of knowledge and insufficient skills for CHA₂DS₂-VASc scores and their components. Improvements in the awareness of the CHA₂DS₂-VASc score and its detailed scoring criteria are urgently needed for Chinese medical professionals. Therefore, education programs concerning the introduction of stroke risk evaluation for AF patients and the development of referencing scoring tools are necessary.

Long‐term antithrombotic therapy for patients with atrial fibrillation and stable coronary artery disease

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

To assess the efficacy and safety of different long‐term antithrombotic regimens for people with AF and stable CAD.