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

Association between physical activity changes and incident myocardial infarction after ischemic stroke: a nationwide population-based study

BACKGROUND

The impact of changes in physical activity after ischemic stroke (IS) on the subsequent myocardial infarction (MI) risk is not fully understood. We aimed to investigate the effects of changes in physical activity on the risk of MI after acute IS using data from the Korean National Health Insurance Services Database.

METHODS

224,764 patients newly diagnosed with IS between 2010 and 2016 who underwent two serial biannual health checkups were included. The participants were divided into four categories according to changes in their physical activity: persistent non-exercisers, new exercisers, exercise dropouts, and exercise maintainers. The primary outcome was a new diagnosis of incident MI. Multivariable Cox proportional models were used to assess the effects of changes in exercise habits on the risk of MI.

RESULTS

After a median of 4.25 years of follow-up, 6,611 (2.94%) MI cases were observed. After adjusting for confounders, new exercisers and exercise maintainers were significantly associated with a lower risk of incident MI than persistent non-exercisers (aHR, 0.849; 95% CI, 0.792-0.911; P-value < 0.001; and aHR, 0.746; 95% CI, 0.696-0.801; P-value < 0.001, respectively). Effects were consistent across sexes, more pronounced in those > 65 years. Notably, any level of physical activity after stroke was associated with a reduced MI risk compared to no exercise.

CONCLUSIONS

In this nationwide cohort study, commencing or sustaining physical activity after an IS corresponded to a diminished likelihood of subsequent MI development. Advocating physical activity in ambulatory stroke survivors could potentially attenuate the prospective risk of MI.

Outcomes of non-vitamin K oral anticoagulants for secondary prevention in ischemic stroke with atrial fibrillation

Previous studies have rarely investigated the role of non-vitamin K oral anticoagulants (NOAC) and warfarin in the secondary prevention of ischemic stroke patients with nonvalvular atrial fibrillation (NVAF). In this study, we compared the effectiveness and safety of NOAC and warfarin for secondary prevention in Korean ischemic stroke patients with NVAF. Based on the Korean National Health Insurance Service Database, this study included 21,064 oral anticoagulants-naïve acute ischemic stroke patients with NVAF between July 2015 and June 2019. The main study outcomes included ischemic stroke, systemic embolism, major bleeding, and death. During the observational periods, NOAC users had a significantly decreased risk of ischemic stroke + systemic embolism (adjusted hazard ratio [aHR] 0.86; 95% confidence interval [CI] 0.78-0.95), ischemic stroke (aHR 0.89; 95% CI 0.81-0.99), major bleeding (aHR 0.78; 95% CI 0.68-0.89), and all-cause death (aHR 0.87; 95% CI 0.81-0.93). Standard-dose NOAC users had a lower risk of ischemic stroke, systemic embolism, and major bleeding events than warfarin users. In contrast, low-dose NOAC users did not differ in risk from warfarin users for all outcomes. In conclusion, NOACs were associated with a lower risk of secondary thromboembolic events and bleeding complications in Korean ischemic stroke patients with NVAF than warfarin.

The Prescription trends and dosing appropriateness analysis of novel oral anticoagulants in ischemic stroke patients: a retrospective study of 9 cities in China

Background: Novel oral anticoagulants (NOACs) have been recommended by guidelines as the first-line drugs for preventing cardiogenic stroke. We aimed to provide an overview of the prescription trends and dosing appropriateness of NOACs in China. Methods: We conducted a retrospective analysis of NOAC prescriptions using the Hospital Prescription Analysis Cooperation Project data from 2016 to 2022. Various patient features, such as gender, age, city, year, source, department visited, original diagnosis, dosing, cost, and insurance type, were collected and analyzed to examine the trends and dosing appropriateness of NOAC usage in ischemic stroke patients. Results: 62,014 NOAC prescriptions were analyzed, including 16,602 for dabigatran, 45,253 for rivaroxaban, and 159 for apixaban. 85.14% of the patients were aged 65 or above, and tertiary hospitals accounted for 95.97% of NOAC prescriptions. NOAC prescriptions rose from 1828 in 2016 to 13,998 in 2021 but dropped to 13,166 in 2022. The percentage of annual prescriptions for NOACs among stroke patients has increased from 0.05% in 2016 to 0.37% in 2022. Total drug cost increased from ¥704541.18 in 2016 to ¥4128648.44 in 2021, then decreased to ¥1680109.14 in 2022. Prescriptions were divided into 48,321 appropriate and 11,262 inappropriate dosing groups, showing significant differences in medications, age, year, city type, hospital level, source, insurance type, and department visited (all p < 0.001). The median drug cost for inappropriate dosing was higher than for appropriate dosing (¥55.20 VS ¥83.80). The top comorbidities in ischemic stroke patients were atrial fibrillation (35.30%), hypertension (32.75%), and coronary heart disease (16.48%). Conclusion: The application of NOACs in the Chinese population is increasing. Our findings highlight the frequent deviation from labeled dosing of NOACs in clinical practice. Continued efforts are necessary to promote the appropriate use of NOACs according to the standard dosage in the drug insert.

Prescribing Patterns and Outcomes of Edoxaban in Atrial Fibrillation Patients From Asia - One-Year Data From the Global ETNA-AF Program

Background: This study reports prescribing patterns and the 1-year effectiveness and safety of edoxaban in an Asian cohort of Edoxaban Treatment in routiNe clinical prActice (ETNA)-Atrial Fibrillation (AF) patients. Methods and Results: The Global ETNA-AF program integrates prospective, observational, noninterventional regional studies, collecting data on characteristics and clinical outcomes of patients with AF receiving edoxaban for stroke prevention. Baseline characteristics, medical history, and 1-year clinical event rates were assessed in patients from South Korea, Taiwan, Hong Kong, and Thailand. Clinically relevant events assessed at 12 months included all-cause death, cardiovascular death, ischemic and hemorrhagic stroke, systemic embolic events (SEEs), bleeding, and net clinical outcome (NCO). Overall, 3,359 patients treated with edoxaban 60 or 30 mg once daily completed 1-year follow-up; 70.9% of patients received recommended dosing according to local labels. Baseline mean±standard deviation age was 71.7±9.6 years, CHA2DS2-VASc score was 3.1±1.5, and modified HAS-BLED score was 2.3±1.1. Mean age and sex were similar across countries/regions. The 1-year event rate for all-cause death was 1.8%; major bleeding, 1.3%; ischemic stroke, 1.1%; cardiovascular mortality, 0.7%; hemorrhagic stroke, 0.3%; SEEs, 0%; and NCO, 4.1%; with differences observed between countries/regions and dosing groups. Conclusions: Most Asian patients with AF were prescribed recommended edoxaban dosing in routine care settings. At 1-year follow-up, this analysis supports the effectiveness and safety of edoxaban in these patients.

Impact of changes in physical activity and incident fracture after acute ischemic stroke

Stroke survivors are at an increased risk of falls and fractures. Physical activity is inversely associated with the fracture risk in the general population. However, the association between incident fracture risk and changes in habitual physical activity before and after an index stroke remains unclear. This study attempted to explore the association between incident fracture risk and changes in physical activity after stroke. Using the claims database of the National Health Insurance Program in Korea, participants with their first ischemic stroke between 2010 and 2016 were enrolled in the study. The participants were divided into four groups according to changes in physical activity habits evaluated using two consecutive self-reported questionnaires before and after stroke, if available: persistent non-exercisers, exercise dropouts, new exercisers, and persistent exercisers. The primary outcome was a composite of vertebral, hip, and other fractures. We performed multivariable Cox proportional hazard regression analysis and provided adjusted hazard ratios and 95% confidence intervals for each outcome. Among 202,234 participants included from 1,005,879 datasets, 16,621 (8.22%) experienced any type of fracture as the primary outcome. After multivariable adjustment, exercise dropouts (n = 37,106), new exercisers (n = 36,821), and persistent exercisers (n = 74,647) had a significantly reduced risk of any type of fracture (aHR 0.932, 95% CI 0.893-0.973; aHR 0.938, 95% CI 0.900-0.978; aHR 0.815, 95% CI 0.780-0.852, respectively) compared to the persistent non-exercisers (n = 53,660). Furthermore, regardless of pre-stroke exercise status, those who exercised ≥ 1000 metabolic equivalents of tasks post-stroke had a significantly reduced risk of fractures. Initiating or continuing moderate-to-vigorous regular physical activity after acute ischemic stroke was associated with a significantly lower risk of incident fractures, including hip, vertebral, and other types.

A novel shared decision-making (SDM) tool for anticoagulation management in atrial fibrillation: protocol for a prospective, cluster randomized controlled trial

BACKGROUND

Atrial fibrillation (AF) is a common arrhythmia that requires anticoagulation therapy to prevent stroke. However, there is still a significant under-/over-treatment in stroke prevention for patients with AF. The adherence and the risk of bleeding associated with oral anticoagulation therapy (OACs) are major concerns. Shared decision-making (SDM) is an approach that involves patients and healthcare providers in making decisions about treatment options. This study aims to assess the effectiveness of a novel SDM tool for anticoagulation management in AF.

METHODS

The study will be a prospective, cluster randomized controlled trial involving 440 patients with AF in 8 community health service centers (clusters) in Shanghai, China. The SDM group will receive anticoagulation management through the novel SDM tool, while the control group will receive standard care. The follow-up period will be at least 2 years. The primary outcome will be any bleeding event, while secondary outcomes include the accordance of stroke prophylaxis for AF according to the current guidelines, time in therapeutic range (TTR), the occurrences of major bleeding and thrombosis events, and patient knowledge, adherence, and satisfaction.

DISCUSSION

This study will provide evidence of the effectiveness of shared decision-making in improving the appropriateness of OAC use in Chinese AF patients. The findings may inform the development of guidelines and policies for the management of AF and anticoagulation therapy in China and other countries.

TRIAL REGISTRATION

ChiCTR ChiCTR2200062123. Registered on 23 July 2022.

Systematic Review and Meta-Analysis of Direct Oral Anticoagulants Versus Warfarin in Atrial Fibrillation With Low Stroke Risk

Pivotal trials comparing direct oral anticoagulants (DOACs) against warfarin in patients with atrial fibrillation (AF) predominantly involved patients with high stroke risk. This study aimed to evaluate the efficacy and safety of DOAC versus warfarin in patients with low stroke risk. An online literature search was conducted to retrieve studies comparing clinical outcomes between patients treated with DOAC versus warfarin for AF, reporting outcomes for patients at low or minimal risk of stroke (CHA2DS2-VASc scores ranging from 0 to 2 or CHADS2 scores ranging from 0 to 1). The primary outcome was the occurrence of stroke or systemic embolism. Secondary outcomes included major bleeding, intracranial hemorrhage, and all-cause mortality. Hazard ratios for all outcomes were pooled in random-effects meta-analyses. A network meta-analysis of individual DOACs versus warfarin was also conducted. In total, 11 studies (132,980 patients) were included. DOAC was associated with a significantly lower risk of stroke or systemic embolism (hazard ratio 0.85, 95% confidence interval 0.75 to 0.96, p = 0.008, I2 = 0%), major bleeding, intracranial hemorrhage, and mortality compared with warfarin. This benefit persisted even when study arms which had CHA2DS2-VASc scores of 2 were excluded. When restricted to 3 studies investigating only patients with a single nongender-related stroke risk factor, significant benefit was seen only for the outcome of major bleeding. In the network meta-analysis, only dabigatran was superior to warfarin for all 4 outcomes. In conclusion, DOACs should be the standard of care in low-risk patients with AF who require anticoagulation. In particular, dabigatran appears to have the best balance of stroke prevention and reduction in major bleeding.

Efficacy and Safety of Novel Oral Anticoagulants in Atrial Fibrillation: A Systematic Review

In recent times, novel oral anticoagulants (NOACs)/direct oral anticoagulants (DOACs) have emerged as an alternative to the traditionally used Vitamin K oral antagonists (VKA) like warfarin for the treatment of atrial fibrillation (AF). This systematic review and meta-analysis aims to evaluate the efficacy and safety of NOACs in patients with AF and, thus, the related thromboembolic risks and sequelae. Of the 131 published articles we examined, 11 were included in an in-depth systematic review. The articles we reviewed were from the past ten years, from 2013 onward. The analysis derived the efficacy and safety of NOACs in patients with AF and also included different patients' baseline characteristics and subgroups. This systematic review reiterates previous research findings of superior efficacy and safety of the use of NOACs in the AF population and also illuminates certain head-to-head comparisons of individual NOACs with warfarin. It digressed into subgroups of patients with different baseline characteristics to provide evidence and support the existing guidelines for the use of NOACs in the treatment of AF. Overall, there is marked efficacy and safety of NOACs in patients with AF, be they elderly or Asian, with decreased renal function, or with other comorbidities. Adherence to NOACs was also satisfactory. Despite such a review, there needs to be more research on vast subgroups and also on reversal antidotes like andexanet alfa and idarucizumab, as well as more head-to-head analysis between NOACs over a long duration of study, which would provide more answers and pinpoint reasons as to the differences that exist between demographics and subgroups in the usage of NOACs.

Real world time trends in antithrombotic treatment for newly diagnosed atrial fibrillation in China: reports from the GLORIA-AF Phase III registry : Trends in antithrombotic therapy use in China

BACKGROUND

Stroke prevention with oral anticoagulant (OAC) therapy, including non-vitamin K antagonist oral anticoagulants (NOACs), is recommended in patients with atrial fibrillation (AF). This analysis describes the antithrombotic prescription patterns for Chinese patients enrolled post-dabigatran approval during Phase II and III of the Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation (GLORIA-AF) program in China.

METHODS

Patients aged ≥ 18 years with newly diagnosed (< 3 months before baseline visit) nonvalvular AF at risk of stroke (CHA₂DS₂-VASc score ≥ 1) were consecutively enrolled in the GLORIA-AF registry. This cross-sectional analysis provides descriptive comparison of Chinese patients in Phase III (2015-2016) with those enrolled in Phase II (2013-2014).

RESULTS

Overall, 1,018 and 1,911 Chinese patients were eligible for analysis in Phase II and III, respectively. Most patients (69.6% and 69.1%, respectively) had high stroke risk (CHA₂DS₂-VASc score ≥ 2 for males and ≥ 3 for females). High bleeding risk (HAS-BLED score ≥ 3) rates were similar (17.3% for Phase II, 17.6% for Phase III). In Phase II, 5.8%, 15.2%, 36.7% and 42.2% of patients were prescribed NOACs, vitamin K antagonists (VKAs), antiplatelet therapies or no antithrombotic treatment, respectively. The corresponding figures were 17.2%, 23.5%, 37.4% and 21.8% for patients in Phase III, with an overall increase in OAC prescriptions (NOACs or VKAs). In patients with high stroke risk, the prescription patterns in Phase II were 5.6%, 14.4%, 41.0% and 38.9% for NOACs, VKAs, antiplatelets or no antithrombotic treatment, respectively. The respective proportions in Phase III were 15.1%, 23.5%, 40.9% and 20.5%.

CONCLUSIONS

Since the availability of dabigatran in China, the overall trend of OAC, including NOAC, prescriptions in Chinese patients with nonvalvular AF has increased over time, albeit with VKAs as the most common antithrombotic treatment. Most patients, including those at high stroke risk, remain undertreated according to best practice guidelines.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01468701.

Edoxaban treatment in atrial fibrillation in routine clinical care: One-year outcomes of the prospective observational ETNA-AF study in South Korean patients

Background

The real-world outcomes of edoxaban treatment in patients with atrial fibrillation (AF) were analyzed in the ETNA-AF (Edoxaban Treatment in Routine Clinical Practice) study involving data from multiple regional registries. This report addresses effectiveness and safety of edoxaban in the Korean ETNA-AF population.

Methods

One-year data from 1887 Korean ETNA-AF participants were analyzed according to edoxaban dose and patient age and compared with results of other ETNA-AF registries.

Results

Approximately 70% of patients received the recommended doses of edoxaban (60 mg/30 mg); non-recommended 60 mg and 30 mg doses were prescribed to 9.6% and 19.8% of the patients, respectively. The proportions of reference age (<65 years), youngest-old (65-74 years) and middle-old/oldest-old (≥75 years) groups were 21.4%, 40.2%, and 38.4%, respectively. Incidence of major or clinically relevant nonmajor bleeding was similar within dose (0.57%-1.71%) and age subgroups (1.26%-1.63%). Incidence of net clinical outcome, a composite of stroke, systemic embolic event, major bleeding, and all-cause mortality, was also comparable among dose subgroups (1.14%-3.10%) and age subgroups (2.28%-2.78%). The percentage of Korean patients receiving non-recommended 30 mg (19.8%) was over twice that of the European population (8.4%). However, the clinical outcomes were generally similar among different populations included in the ETNA-AF study.

Conclusions

The outcomes in the Korean ETNA-AF population are like those in the global ETNA-AF population, with overall low event rates of stroke, major bleeding and all-cause mortality across age and dose subgroups. Edoxaban can be used effectively and safely in specific populations of Korean AF patients, including the elderly.

Association between exercise habit changes and incident dementia after ischemic stroke

We aimed to investigate the effects of exercise habit changes on the risk of incident dementia after ischemic stroke using the Korean National Health Insurance Services Database. This study included 223,426 patients with a new diagnosis of ischemic stroke between 2010 and 2016 who underwent two serial ambulatory health checkups. The participants were divided into four categories according to their habit change or regular exercise: persistent non-exercisers, new exercisers, exercise dropouts, and exercise maintainers. The primary outcome was new diagnosis of dementia. Multivariate Cox proportional models were used to assess the effects of changes in exercise habits on the risk of incident dementia. After a median of 4.02 years of follow-up, 22,554 (10.09%) dementia cases were observed. After adjusting for covariates, exercise dropouts, new exercisers, and exercise maintainers were significantly associated with a lower risk of incident dementia than persistent non-exercisers (adjusted hazard ratio [aHR] 0.937; 95% confidence interval [CI] 0.905-0.970, aHR 0.876; 95% CI 0.843-0.909, aHR 0.705; 95% CI 0.677-0.734, respectively). The impact of changes in exercise habit was more prominent in the 40-65 years age group. An energy expenditure ≥ 1000 metabolic equivalents of task-min/wk post-stroke, regardless of pre-stroke physical activity status, was mostly associated with a lower risk of each outcome. In this retrospective cohort study, initiating or continuing moderate-to-vigorous exercise after ischemic stroke was associated with a lower risk of dementia development. Further, pre-stroke regular physical activity also reduced the risk of incident dementia. The promotion of exercise in ambulatory stroke patients may reduce their future risk of incident dementia.

Long-term stroke and major bleeding risk in patients with non-valvular atrial fibrillation: A comparative analysis between non-vitamin K antagonist oral anticoagulants and warfarin using a clinical data warehouse

Introduction

Non-vitamin K antagonist oral anticoagulants (NOACs) has been the drug of choice for preventing ischemic stroke in patients with atrial fibrillation (AF) since 2014. Many studies based on claim data revealed that NOACs had comparable effect to warfarin in preventing ischemic stroke with fewer hemorrhagic side effects. We analyzed the difference in clinical outcomes according to the drugs in patients with AF based on the clinical data warehouse (CDW).

Methods

We extracted data of patients with AF from our hospital's CDW and obtained clinical information including test results. All claim data of the patients were extracted from National Health Insurance Service, and dataset was constructed by combining it with CDW data. Separately, another dataset was constructed with patients who could obtain sufficient clinical information from the CDW. The patients were divided NOAC and warfarin groups. The occurrence of ischemic stroke, intracranial hemorrhage, gastrointestinal bleeding, and death were confirmed as clinical outcome. The factors influencing the risk of clinical outcomes were analyzed.

Results

The patients who were diagnosed AF between 2009 and 2020 were included in the dataset construction. In the combined dataset, 858 patients were treated with warfarin, 2,343 patients were treated with NOACs. After the diagnosis of AF, the incidence of ischemic stroke during follow-up was 199 (23.2%) in the warfarin group, 209 (8.9%) in the NOAC group. Intracranial hemorrhage occurred in 70 patients (8.2%) among the warfarin group, 61 (2.6%) of the NOAC group. Gastrointestinal bleeding occurred in 69 patients (8.0%) in the warfarin group, 78 patients (3.3%) in the NOAC group. NOAC's hazard ratio (HR) of ischemic stroke was 0.479 (95% CI 0.39-0.589, p < 0.0001), HR of intracranial hemorrhage was 0.453 (95% CI 0.31-0.664, p < 0.0001), and HR of gastrointestinal bleeding was 0.579 (95% CI 0.406-0.824, p = 0.0024). In the dataset constructed using only CDW, the NOAC group also had a lower risk of ischemic stroke and intracranial hemorrhage than warfarin group.

Conclusions

In this CDW based study, NOACs are more effective and safer than warfarin in patients with AF even with long-term follow-up. NOACs should be used to prevent ischemic stroke in patients with AF.

Off-label dose direct oral anticoagulants and clinical outcomes in Asian patients with atrial fibrillation: A new evidence of Asian dose

AIM

This study aimed to evaluate the label compliance of DOACs in the Chinese AF population and explore the relationship between inappropriate DOACs dosage and clinical results.

METHODS AND RESULTS

This is a retrospective multicenter cohort study conducted in 14 centers in China. According to the China Food and Drug Administration(CFDA) label and the recommendations of international guidelines, we divided patients into on-label dosage and off-label dosage. We then compared the clinical results after propensity score matching. We collect demographic information through the hospital information system and obtain clinical events through follow-up of patients or their families. Clinical results include major, minor, total bleeding, thrombosis, and all-cause death. 4191 patients with non-valvular AF (NVAF) were included, and approximately 55.6% and 1.7% of AF patients received off-label underdose and off-label overdose of DOACs, respectively. Compared with the on-label dose, DOACs with off-label underdose were associated with a significantly reduced risk of major bleeding (P = 0.004, OR = 0.23,95% CI: 0.08-0.69) and all-cause death (P<0.001, OR = 0.49,95% CI: 0.33-0.73). However, there was no significant difference in thrombotic events (P = 0.865 OR = 1.06,95% CI: 0.54-2.07) and minor bleeding (P = 0.465, OR = 1.10,95% CI: 0.85-1.43) risk.

CONCLUSIONS

About 57.3% of Asian AF patients received an off-label dose of DOACs in daily practice. Off-label underdose DOACs were associated with significantly lower risks of major bleeding, all-cause death, and similar risks of minor bleeding, thrombotic events compared with on-label dose DOACs. Further prospective randomized trials are needed to determine the optimal dose of DOACs in Asian patients with AF at high bleeding risk.

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.

Novel Antithrombotic Agents in Ischemic Cardiovascular Disease: Progress in the Search for the Optimal Treatment

Ischemic cardiovascular diseases have a high incidence and high mortality worldwide. Therapeutic advances in the last decades have reduced cardiovascular mortality, with antithrombotic therapy being the cornerstone of medical treatment. Yet, currently used antithrombotic agents carry an inherent risk of bleeding associated with adverse cardiovascular outcomes and mortality. Advances in understanding the pathophysiology of thrombus formation have led to the discovery of new targets and the development of new anticoagulants and antiplatelet agents aimed at preventing thrombus stabilization and growth while preserving hemostasis. In the following review, we will comment on the key limitation of the currently used antithrombotic regimes in ischemic heart disease and ischemic stroke and provide an in-depth and state-of-the-art overview of the emerging anticoagulant and antiplatelet agents in the pipeline with the potential to improve clinical outcomes.

Impact of Integrating Machine Learning in Comparative Effectiveness Research of Oral Anticoagulants in Patients with Atrial Fibrillation

We aimed to compare the ability to balance baseline covariates and explore the impact of residual confounding between conventional and machine learning approaches to derive propensity scores (PS). The Health Insurance Review and Assessment Service database (January 2012-September 2019) was used. Patients with atrial fibrillation (AF) who initiated oral anticoagulants during July 2015-September 2018 were included. The outcome of interest was stroke/systemic embolism. To estimate PS, we used a logistic regression model (i.e., a conventional approach) and a generalized boosted model (GBM) which is a machine learning approach. Both PS matching and inverse probability of treatment weighting were performed. To evaluate balance achievement, standardized differences, p-values, and boxplots were used. To explore residual confounding, E-values and negative control outcomes were used. In total, 129,434 patients were identified. Although all baseline covariates were well balanced, the distribution of continuous variables seemed more similar when GBM was applied. E-values ranged between 1.75 and 2.70 and were generally higher in GBM. In the negative control outcome analysis, slightly more nonsignificant hazard ratios were observed in GBM. We showed GBM provided a better ability to balance covariates and had a lower impact of residual confounding, compared with the conventional approach in the empirical example of comparative effectiveness analysis.

XaMINA: A Real-World, Prospective, Observational Study of Treatment-Naïve Patients Treated with Rivaroxaban for Stroke Prevention in Atrial Fibrillation in Asia

INTRODUCTION

The efficacy and safety of rivaroxaban for the prevention of stroke and systemic embolism have been demonstrated in Asian and non-Asian patients with non-valvular atrial fibrillation (NVAF) in multiple studies. However, limited published data exist on its use specifically in treatment-naïve patients from the Asia region. Patients in South Korea and Taiwan can now receive rivaroxaban as first-line therapy, allowing for data generation in this patient group.

METHODS

XaMINA was a prospective, real-world, multicenter, single-arm, observational cohort study of patients with NVAF in South Korea and Taiwan naïve to anticoagulation and initiating rivaroxaban. The primary outcome was major bleeding; secondary outcomes included all-cause mortality, symptomatic thromboembolic events, and treatment persistence.

RESULTS

In total, 1094 patients were included and the follow-up was 1 year. The baseline mean CHADS₂ score was 1.63 ± 0.98, mean CHA₂DS₂-VASc score was 2.92 ± 1.42, and mean HAS-BLED score was 1.00 ± 0.75. The primary outcome occurred in 20 (1.8%) patients [incidence rate 2.1 events per 100 patient-years (95% CI 1.35-3.25)]. Thromboembolic events occurred in 9 (0.8%) patients, of whom 5 (0.5%) had stroke, 3 (0.3%) myocardial infarction, and 1 (0.1%) a transient ischemic attack. There were no cases of non-central nervous system systemic embolism, and 735 (67.2%) patients persisted with rivaroxaban treatment for 1 year.

CONCLUSION

XaMINA demonstrated low incidence rates of major bleeding events and thromboembolic events in patients with NVAF newly initiating rivaroxaban in South Korea and Taiwan, consistent with previous real-world studies reconfirming the results of the ROCKET AF study.

TRIAL REGISTRATION

The trial was registered on ClinicalTrials.gov (identifier NCT03284762) on 15 September 2017.

Is the Risk of Diabetes Lower in Patients With Atrial Fibrillation Treated With Direct Oral Anticoagulant Compared to Warfarin?

Background

The use of anticoagulants is an established strategy to prevent stroke, embolism, and cardiovascular mortality in patients with atrial fibrillation (AF), but its role in the prevention of incident diabetes is unclear. We aimed to investigate this question by using participant data from cohort studies.

Methods

We conducted a meta-analysis of participants to investigate the impact of direct oral anticoagulants (DOACs) on the risk of new-onset diabetes in AF patients. The collection of related data was performed in the PubMed and EMBASE databases until December 2021, including studies associated with evaluating the correlation between DOACs and incident diabetes. The hazard ratios (HRs) and 95% confidence intervals (CIs) were adjusted by the random-effects model with an inverse variance method.

Results

Two cohort studies with a total of 24,434 patients were included in this study (warfarin: n = 6,906; DOACs: n = 17,528). Compared with warfarin, the use of DOACs could reduce the incident diabetic risk in AF patients (HR = 0.75, 95%CI: 0.68–0.82). Investigations about the effects of three major classes of DOACs showed that the individual use of dabigatran (HR = 0.76, 95%CI: 0.64–0.90), rivaroxaban (HR = 0.74, 95%CI: 0.64–0.87), apixaban (HR = 0.74, 95%CI: 0.60–0.92) and the combined use of rivaroxaban and apixaban (HR = 0.74, 95%CI: 0.66–0.84) could reduce the risk of new-onset diabetes compared with warfarin. This risk reduction effect could be observed in both male and female groups (HR = 0.73, 95%CI: 0.64–0.84, P &lt; 0.00001; HR = 0.82, 95%CI: 0.82–0.99, P = 0.04).

Conclusions

Treatment with DOACs compared with warfarin reduced the risk of new-onset diabetes in both male and female patients with AF.

Drug Utilization Pattern of Oral Anticoagulants in Patients with Atrial Fibrillation: A Nationwide Population-Based Study in Korea

INTRODUCTION

Treatment persistence for anticoagulant therapy is important in preventing thromboembolism in nonvalvular atrial fibrillation (NVAF) patients. Understanding drug utilization pattern and treatment changes in oral anticoagulant (OAC) users may facilite better NVAF management. Thus, our study aimed to examine OAC treatment patterns preceding events leading to switch or discontinuation and medication adherence in Korean NVAF patients.

METHODS

We conducted a drug utilization study on all Korean patients with atrial fibrillation (AF) newly prescribed OACs between July 2015 and November 2016 using the national claims data. We assessed treatment changes such as switching and discontinuation from index OAC and relevant events preceding the change and examined patient characteristics as predictors of changes that occurred among OAC users. Medication adherence was compared among OAC users by calculating the medication possession ratio (MPR).

RESULTS

A total of 48,389 NVAF patients were identified who initiated OACs within the study period. Most initiated nonvitamin K antagonist oral anticoagulants (NOACs) (22% apixaban, 24% dabigatran, 37% rivaroxaban), and 18% initiated warfarin. The frequency of switch to another OAC was 8.8% for apixaban, 16.1% for dabigatran, 6.6% for rivaroxaban, and 19.1% for warfarin. The frequency of discontinuation was lower for apixaban (22.9%), dabigatran (26.3%), and rivaroxaban (25.7%) than warfarin (31.6%). Compared to warfarin, NOAC users were less likely to switch treatment. Thromboembolic event was the most common clinical event preceding switch from warfarin to NOAC and from NOAC to warfarin. Discontinuation of OAC was often preceded by a bleeding event. Patients who initiated apixaban showed significantly higher mean MPR compared to those on dabigatran and warfarin.

CONCLUSION

In real-world practice in Korea, we have observed treatment change to be common in OAC users. Our results indicate better medication adherence with NOACs than with warfarin. (ClinicalTrials.gov registration number NCT03572972).

Choice of antithrombotic therapy for patients with atrial fibrillation undergoing carotid angioplasty and stenting: a nationwide population-based study

Nonvalvular atrial fibrillation (NVAF) and carotid stenosis are important risk factors for stroke. Carotid angioplasty and stent placement (CAS) is recommended for patients with symptomatic high-grade carotid stenosis. The optimal medical management for patients with NVAF after CAS remains unclear. We aimed to clarify this issue using real-world data from the Taiwanese National Health Insurance Research Database (NHIRD). In total, 2116 consecutive NVAF patients who received CAS between January 1, 2010, and December 31, 2016, from NHIRD were divided into groups based on post-procedure medication as follows: only antiplatelet agent (OAP, n = 587); only anticoagulation agent (OAC, n = 477); dual antiplatelet agents (DAP, n = 49); and a combination of antiplatelet and anticoagulation agents (CAPAC, n = 304). Mortality, vascular events, and major bleeding episodes were compared after matching with the Charlson comorbidity index and CHA2DS2-VASc score. The CAPAC and the OAC groups had lower mortality rates than the OAP group (P = 0.0219), with no statistical differences in major bleeding, ischemic stroke, or vascular events. Conclusively, OAC therapy after CAS appears suitable for NVAF patients. CAPAC therapy might be considered as initial therapy or when there is concern about vascular events.

Underutilization of anticoagulants in patients with nonvalvular atrial fibrillation in the era of non-vitamin K antagonist oral anticoagulants

Background

Non-vitamin K antagonist oral anticoagulants (NOACs) are preferred over vitamin K antagonists (VKAs) as oral anticoagulant (OAC) therapy in patients with nonvalvular atrial fibrillation (NVAF). This study aimed to estimate the current status and risk factors of OAC underutilization in the NOAC era.

Method

A cross-sectional study using nationwide claims data was conducted. Elderly patients with NVAF at an increased risk of stroke were selected as candidates for OAC therapy before the index date (July 1, 2018). The status of anticoagulant utilization on the index date and factors influencing the use of anticoagulants was investigated in these patients.

Results

Of the 11,056 patients with NVAF who were eligible for OAC therapy, 7238 (65.5%) were receiving OAC on the index date, and 6302 (87.1%) were receiving NOACs. Patients aged ≥ 75 years had higher anticoagulant utilization than those aged 65–69 years. Among comorbid diseases, while hypertension was the most influential positive factor (odds ratio [OR] = 1.644; confidence interval [CI] = 1.445–1.869) in OAC utilization, severe renal disease was the most influential negative factor (OR = 0.289; CI = 0.200–0.416). Aspirin use had a significantly low OR (OR = 0.097; CI = 0.085–0.110) of anticoagulant use. OAC use was approximately 1.5 times higher in patients with persistent or permanent AF than in those with paroxysmal AF.

Conclusion

Approximately one-third of patients who are recommended anticoagulation therapy do not take OACs, even though the use of NOACs has become more common. It should be widely recognized that aspirin cannot be an alternative to OACs, and anticoagulant therapy should be actively implemented.

Cardiovascular Benefits With Favorable Renal, Amputation and Hypoglycemic Outcomes of SGLT-2 Inhibitors in Type 2 Diabetes From the Asian Perspective: A Population-Based Cohort Study and Systematic Review

OBJECTIVE

We assessed the effects of sodium glucose cotransporter-2 inhibitors (SGLT2is) versus dipeptidyl peptidase-4 inhibitors (DPP4is) in a large real-world Asian cohort with type 2 diabetes (T2D) and performed a systematic review with integrating the present study findings to provide up-to-date evidence from the Asian perspective.

METHODS

New users of SGLT2is or DPP4is were identified from the Taiwan's National Health Insurance Research Database and followed until 2018. Primary outcomes were hospitalization for heart failure (HHF) and three-point major adverse cardiovascular event (3P-MACE; namely, myocardial infarction [MI], stroke, or cardiovascular death). Other outcomes included all-cause death, chronic kidney disease (CKD), amputation, and hospitalized hypoglycemia. Subdistribution hazard models were employed to assess treatment-associated clinical outcomes.

RESULTS

A total of 21,329 SGLT2i and DPP4i propensity-score-matched pairs were analyzed. SGLT2is versus DPP4is showed lower risks of HHF (hazard ratio [95% CI]: 0.52 [0.45-0.59]), 3P-MACE (0.62 [0.55-0.70]), MI (0.63 [0.50-0.79]), stroke (0.60 [0.51-0.70]), all-cause death (0.57 [0.49-0.67]), CKD (0.46 [0.43-0.50]), amputation (0.64 [0.42-0.98]), and hospitalized hypoglycemia (0.54 [0.45-0.64]). Our results were consistent with findings from a systematic review.

CONCLUSION

Among Asian patients with T2D, SGLT2is versus DPP4is showed benefits for several clinical outcomes. More research is warranted to explore the heterogeneous treatment effects of SGLT2is and DPP4is by race/ethnicity.

Can Machine Learning from Real-World Data Support Drug Treatment Decisions? A Prediction Modeling Case for Direct Oral Anticoagulants

BACKGROUND

Decision making for the "best" treatment is particularly challenging in situations in which individual patient response to drugs can largely differ from average treatment effects. By estimating individual treatment effects (ITEs), we aimed to demonstrate how strokes, major bleeding events, and a composite of both could be reduced by model-assisted recommendations for a particular direct oral anticoagulant (DOAC).

METHODS

In German claims data for the calendar years 2014-2018, we selected 29 901 new users of the DOACs rivaroxaban and apixaban. Random forests considered binary events within 1 y to estimate ITEs under each DOAC according to the X-learner algorithm with 29 potential effect modifiers; treatment recommendations were based on these estimated ITEs. Model performance was evaluated by the c-for-benefit statistics, absolute risk reduction (ARR), and absolute risk difference (ARD) by trial emulation.

RESULTS

A significant proportion of patients would be recommended a different treatment option than they actually received. The stroke model significantly discriminated patients for higher benefit and thus indicated improved decisions by reduced outcomes (c-for-benefit: 0.56; 95% confidence interval [0.52; 0.60]). In the group with apixaban recommendation, the model also improved the composite endpoint (ARR: 1.69 % [0.39; 2.97]). In trial emulations, model-assisted recommendations significantly reduced the composite event rate (ARD: -0.78 % [-1.40; -0.03]).

CONCLUSIONS

If prescribers are undecided about the potential benefits of different treatment options, ITEs can support decision making, especially if evidence is inconclusive, risk-benefit profiles of therapeutic alternatives differ significantly, and the patients' complexity deviates from "typical" study populations. In the exemplary case for DOACs and potentially in other situations, the significant impact could also become practically relevant if recommendations were available in an automated way as part of decision making.HighlightsIt was possible to calculate individual treatment effects (ITEs) from routine claims data for rivaroxaban and apixaban, and the characteristics between the groups with recommendation for one or the other option differed significantly.ITEs resulted in recommendations that were significantly superior to usual (observed) treatment allocations in terms of absolute risk reduction, both separately for stroke and in the composite endpoint of stroke and major bleeding.When similar patients from routine data were selected (precision cohorts) for patients with a strong recommendation for one option or the other, those similar patients under the respective recommendation showed a significantly better prognosis compared with the alternative option.Many steps may still be needed on the way to clinical practice, but the principle of decision support developed from routine data may point the way toward future decision-making processes.

Patient perception and treatment convenience of dabigatran versus vitamin K antagonist when used for stroke prophylaxis in atrial fibrillation: Real-world Evaluation of Long-term Anticoagulant Treatment Experience (RE-LATE) study

Purpose

Dabigatran is a direct thrombin inhibitor approved for stroke prophylaxis in patients with non-valvular atrial fibrillation (NVAF). Real-world data about patient preference, satisfaction and convenience in patients in Asia are not available. The study aimed to explore the perception of patients with newly diagnosed NVAF regarding dabigatran versus vitamin K antagonists (VKAs), when used for stroke prevention.

Patients and methods

This was a multinational, multicentre, non-interventional study involving 49 sites across 5 countries in South East Asia and South Korea where 934 patients newly diagnosed with NVAF were initiated on either dabigatran (N=591) or VKA (N=343). Data were collected at baseline and over two follow-up visits across 6 months. Treatment satisfaction and patient convenience were evaluated using the Perception on Anticoagulant Treatment Questionnaire-2 (PACT-Q2).

Results

The mean age of the patients was 65.9±10.4 years, and 64.2% were male. Mean CHA₂DS₂-VASc score was 2.4±1.5, and mean HAS-BLED score was 1.2±0.9. At baseline, patients initiated on dabigatran had higher stroke risk, bleeding risk, creatinine clearance and proportion of patients with concomitant illnesses compared with patients initiated on VKAs. Treatment convenience was perceived to be significantly better with dabigatran versus VKAs at visits 2 and 3 (p=0.0423 and 0.0287, respectively). Treatment satisfaction was significantly better with dabigatran compared with VKAs at visit 3 (p=0.0300).

Conclusion

In this study, dabigatran is associated with better patient perception in terms of treatment convenience and satisfaction compared with VKAs when used for stroke prevention in newly diagnosed NVAF patients from South East Asia and South Korea.

Trial registration number

NCT02849509.

Plain language summary

Patient satisfaction with dabigatran versus VKAs in South East Asia. Patients with atrial fibrillation are at high risk of stroke and require anticoagulants for stroke prevention. Two such anticoagulants are dabigatran and VKAs. We wanted to compare the extent of satisfaction and treatment convenience among newly diagnosed patients with atrial fibrillation from the South East Asian region when they were given either dabigatran or VKAs. Consenting patients filled out a standardised questionnaire called the PACT-Q2 over three visits after they were started on either dabigatran (591 patients) or VKAs (343 patients). We found that satisfaction and convenience were significantly higher when patients received dabigatran than when they received VKAs.

Reappraisal of Non-vitamin K Antagonist Oral Anticoagulants in Atrial Fibrillation Patients: A Systematic Review and Meta-Analysis

Background: Recent observational studies have compared effectiveness and safety profiles between non-vitamin K antagonist oral anticoagulants (NOACs) and warfarin in patients with atrial fibrillation (AF). Nevertheless, the confounders may exist due to the nature of clinical practice-based data, thus potentially influencing the reliability of results. This systematic review and meta-analysis were conducted to compare the effect of NOACs with warfarin based on the propensity score-based observational studies vs. randomized clinical trials (RCTs).

Methods: Articles included were systematically searched from the PubMed and EMBASE databases until March 2021 to obtain relevant studies. The primary outcomes were stroke or systemic embolism (SSE) and major bleeding. Hazard ratios (HRs) and 95% confidence intervals (CIs) of the outcomes were extracted and then pooled by the random-effects model.

Results: A total of 20 propensity score-based observational studies and 4 RCTs were included. Compared with warfarin, dabigatran (HR, 0.82 [95% CI, 0.71–0.96]), rivaroxaban (HR, 0.80 [95% CI, 0.75–0.85]), apixaban (HR, 0.75 [95% CI, 0.65–0.86]), and edoxaban (HR, 0.71 [95% CI, 0.60–0.83]) were associated with a reduced risk of stroke or systemic embolism, whereas dabigatran (HR, 0.76 [95% CI, 0.65–0.87]), apixaban (HR, 0.61 [95% CI, 0.56–0.67]), and edoxaban (HR, 0.58 [95% CI, 0.45–0.74]) but not rivaroxaban (HR, 0.92 [95% CI, 0.84–1.00]) were significantly associated with a decreased risk of major bleeding based on the observational studies. Furthermore, the risk of major bleeding with dabigatran 150 mg was significantly lower in observational studies than that in the RE-LY trial, whereas the pooled results of observational studies were similar to the data from the corresponding RCTs in other comparisons.

Conclusion: Data from propensity score-based observational studies and NOAC trials consistently suggest that the use of four individual NOACs is non-inferior to warfarin for stroke prevention in AF patients.

Effectiveness and safety of non-vitamin K antagonist oral anticoagulants in patients with non-valvular atrial fibrillation: A nationwide, population-based study in Korea

BACKGROUND

To compare the risk of stroke/systemic embolism (S/SE) and major bleeding (MB) between non-vitamin K antagonist oral anticoagulants (NOACs) in patients with atrial fibrillation (AF), this retrospective study was conducted using the Korean Health Insurance Review & Assessment Service (HIRA) claims database.

METHODS

Patients with AF who initiated NOACs (apixaban, dabigatran, and rivaroxaban) from July 1, 2015 to November 30, 2016 were included. We applied inverse probability of treatment weighting (IPTW) method using propensity score to make weighted populations having similar characteristics between groups. Hazard ratio (HR) of S/SE and MB were estimated by Cox proportional hazard model.

RESULTS

Of the 39 783 patients with AF, 10 564; 11 418; and 17 801 used apixaban, dabigatran, and rivaroxaban, respectively. The mean CHA2DS2-VASc and HAS-BLED scores were 4.59 ~ 4.69 and 3.58 ~ 3.62, respectively, among all patients after applying IPTW. For S/SE, there were no significant differences between NOACs (HR [95% confidence interval (CI)]): apixaban vs dabigatran (0.99 [0.87-1.13]), apixaban vs rivaroxaban (0.95 [0.84-1.07]), and dabigatran vs rivaroxaban (0.96 [0.85-1.08]). For MB (HR [95% CI]), both apixaban (0.77 [0.68-0.86]) and dabigatran (0.88 [0.79-0.98]) had a significantly lower risk compared with rivaroxaban. Apixaban also had a significantly lower risk of MB compared with dabigatran (0.87 [0.76-0.99]).

CONCLUSIONS

In real-world practice among Korean AF patients with relatively high risk of stroke and bleeding, there were no significant differences in the risk of S/SE between all NOAC comparisons. Apixaban was associated with lower risk of MB than dabigatran and rivaroxaban.

Impact of Reduced-Dose Nonvitamin K Antagonist Oral Anticoagulants on Outcomes Compared to Warfarin in Korean Patients with Atrial Fibrillation: A Nationwide Population-Based Study

Reduced-dose nonvitamin K antagonist oral anticoagulants (NOACs) are commonly prescribed to Asian patients with nonvalvular atrial fibrillation (NVAF). We aimed to compare the risk of stroke/systemic embolism (S/SE) and major bleeding (MB) between patients treated with reduced-dose NOACs and those treated with warfarin, using the claims database in Korea. Patients with NVAF newly initiated on oral anticoagulants (OACs; apixaban, dabigatran, rivaroxaban, and warfarin) between 1 July 2015 and 30 November 2016 were included. Among all patients with NVAF treated with OACs, 5249, 6033, 7602, and 8648 patients were treated with reduced-dose apixaban, dabigatran, rivaroxaban, and warfarin, respectively. Patients treated with reduced-dose NOACs were older and had higher CHA₂DS₂-VASc and HAS-BLED scores than those treated with warfarin. Compared to warfarin, all reduced-dose NOACs showed significantly lower risk of S/SE (hazard ratios (95% confidence interval), 0.63 (0.52–0.75) for apixaban; 0.51 (0.42–0.61) for dabigatran; and 0.67 (0.57–0.79) for rivaroxaban) and MB (0.54 (0.45–0.65) for apixaban; 0.58 (0.49–0.69) for dabigatran; 0.73 (0.63–0.85) for rivaroxaban). In the real-world practice among Asians with NVAF, all reduced-dose NOACs were associated with a significantly lower risk of S/SE and MB compared to those of warfarin.

Direct comparison of non-vitamin K antagonist oral anticoagulant versus warfarin for stroke prevention in non-valvular atrial fibrillation: a systematic review and meta-analysis of real-world evidences

Background

To overcome the several drawbacks of warfarin, non-vitamin K antagonist oral anticoagulants (NOACs) were developed. Even though randomized controlled trials (RCTs) provided high-quality evidence, the real-world evidence is still needed. This systematic review and meta-analysis proposed to measure the safety and efficacy profile between warfarin and NOACs in non-valvular atrial fibrillation (NVAF) patients in preventing stroke.

Results

We collected articles about the real-world studies comparing warfarin and NOACs for NVAF patients recorded in electronic scientific databases such as Embase, ProQuest, PubMed, and Cochrane. The pooled hazard ratio (HR) and 95% confidence interval (CI) were estimated using the generic inverse variance method. A total of 34 real-world studies, including 2287288 NVAF patients, were involved in this study. NOACs effectively reduced the stroke risk than warfarin (HR 0.77; 95% CI 0.69 to 0.87; p < 0.01). Moreover, NOACs effectively lowered all-cause mortality risk (HR 0.71; 95% CI 0.63 to 0.81; p < 0.01). From the safety aspect, compared to warfarin, NOACs significantly reduced major bleeding risk (HR 0.68; 95% CI 0.54 to 0.86; p < 0.01) and intracranial bleeding risk (HR 0.54; 95% CI 0.42 to 0.70; p < 0.01). However, NOACs administration failed to decrease gastrointestinal bleeding risk (HR 0.78; 95% CI 0.58 to 1.06; p = 0.12).

Conclusions

In NVAF patients, NOACs were found to be more effective than warfarin at reducing stroke risk. NOACSs also lowered the risk of all-cause mortality, cerebral hemorrhage, and severe bleeding in NVAF patients compared to warfarin.

Supplementary Information

The online version contains supplementary material available at 10.1186/s43044-021-00194-1.

Left atrial appendage occlusion for ischemic stroke prevention in patients with non-valvular atrial fibrillation: clinical expert opinion and consensus statement for the Asian-Pacific region

PURPOSE

To develop a consensus statement for left atrial appendage occlusion (LAAO) in Asian-Pacific patients with non-valvular atrial fibrillation (NVAF) at risk of ischemic stroke. The need for such a region-specific consensus was indicated by the relative paucity of clinical evidence for LAAO and oral anticoagulation therapy obtained in Asian-Pacific populations and the specific stroke and bleeding characteristics of this population.

METHODS

Consensus was developed by discussion and evaluation of available evidence and expert opinions during a 2-day meeting attended by clinical experts from the Asian-Pacific regions.

RESULTS

The consensus statement arrived at provides recommendations based on available evidence and expert opinions regarding LAAO in Asian-Pacific patients. Gaps in the evidence and other areas requiring further research were identified.

CONCLUSION

LAAO is an alternative device-based therapy in carefully selected patients with NVAF at risk of ischemic stroke. However, evidence for LAAO is primarily obtained from Caucasian populations, and data on LAAO in Asian-Pacific patients are scarce. While the present consensus statement addresses several therapy-related aspects based on careful interpretation of available evidence and expert opinions, other areas require additional evidence derived from Asian-Pacific populations.

Non-vitamin K antagonist oral anticoagulants in Asian patients with atrial fibrillation: evidences from the real-world data

The role of non-vitamin K antagonist oral anticoagulants (NOACs) in stroke prevention remains unclear in Asian patients with atrial fibrillation (AF). Therefore, we performed a meta-analysis to compare the efficacy and safety outcomes of NOACs in Asian patients with AF from the real-world settings. The PubMed and Embase databases were systematically searched to identify eligible observational studies until June 2019. The odds ratios (OR) and 95% confidence intervals (CIs) were calculated and then pooled by a random-effects model. A total of 18 observational studies were included. Compared with warfarin, dabigatran (OR, 0.56, 95% CI 0.43-0.73), rivaroxaban (OR, 0.54, 95% CI 0.44-0.67), apixaban (OR, 0.41, 95% CI 0.35-0.48), and edoxaban (OR, 0.19, 95% CI 0.14- 0.25) reduced the risk of major bleeding, while dabigatran (OR, 0.78, 95% CI 0.71-0.85), rivaroxaban (OR, 0.74, 95% CI 0.68-0.82), and edoxaban (OR, 0.29, 95% CI 0.22-0.39) were associated with reduced risks of stroke or systemic embolism. In addition, dabigatran versus apixaban was associated with increased risks of ischemic stroke and gastrointestinal bleeding, while rivaroxaban versus apixaban was associated with elevated risks of stroke or systemic embolism, ischemic stroke, intracranial hemorrhage, and gastrointestinal bleeding. In Asian patients with AF, NOACs are non-inferior to warfarin for stroke prevention, and apixaban may be a better choice compared with dabigatran or rivaroxaban.

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

The disease burden of AF is greater in Asia-Pacific than other areas of the world. Direct oral anticoagulants (DOACs) have emerged as effective alternatives to vitamin K antagonists (VKA) for preventing thromboembolic events in patients with AF. The Asian Pacific Society of Cardiology developed this consensus statement to guide physicians in the management of AF in Asian populations. Statements were developed by an expert consensus panel who reviewed the available data from patients in Asia-Pacific. Consensus statements were developed then put to an online vote. The resulting 17 statements provide guidance on the assessment of stroke risk of AF patients in the region, the appropriate use of DOACs in these patients, as well as the concomitant use of DOACs and antiplatelets, and the transition to DOACs from VKAs and vice versa. The periprocedural management of patients on DOAC therapy and the management of patients with bleeding while on DOACs are also discussed.

Surgery for Coagulopathy-Related Intracerebral Hemorrhage: Craniotomy vs. Minimally Invasive Neurosurgery

Coagulopathy-related intracerebral hemorrhage (ICH) is life-threatening. Recent studies have shown promising results with minimally invasive neurosurgery (MIN) in the reduction of mortality and improvement of functional outcomes, but no published data have recorded the safety and efficacy of MIN for coagulopathy-related ICH. Seventy-five coagulopathy-related ICH patients were retrospectively reviewed to compare the surgical outcomes between craniotomy (n = 52) and MIN (n = 23). Postoperative rebleeding rates, morbidity rates, and mortality at 1 month were analyzed. Postoperative Glasgow Outcome Scale Extended (GOSE) and modified Rankin Scale (mRS) scores at 1 year were assessed for functional outcomes. Morbidity, mortality, and rebleeding rates were all lower in the MIN group than the craniotomy group (8.70% vs. 30.77%, 8.70% vs. 19.23%, and 4.35% vs. 23.08%, respectively). The 1-year GOSE score was significantly higher in the MIN group than the craniotomy group (3.96 ± 1.55 vs. 3.10 ± 1.59, p = 0.027). Multivariable logistic regression analysis also revealed that MIN contributed to improved GOSE (estimate: 0.99650, p = 0.0148) and mRS scores (estimate: -0.72849, p = 0.0427) at 1 year. MIN, with low complication rates and improved long-term functional outcome, is feasible and favorable for coagulopathy-related ICH. This promising result should be validated in a large-scale prospective study.

Optimal Management of Anticoagulation Therapy in Asian Patients With Atrial Fibrillation

Stroke prevention is the cornerstone of management of atrial fibrillation (AF), and non-vitamin K antagonist oral anticoagulants (NOACs) are commonly prescribed. Because routine monitoring of anticoagulant effects of NOACs is not necessary, appropriate dosing following the criteria of each NOACs defined in pivotal randomized trials is important. Real-world data demonstrate that underdosing NOACs is associated with a higher risk of ischemic stroke without a lower risk of major bleeding. Furthermore, renal function of AF patients should be assessed using the Cockcroft-Gault formula to prevent overestimation that could result in overdosing of NOACs. The assessment of bleeding risk is important, and the HAS-BLED score should be used to help identify patients at high risk of bleeding (HAS-BLED score ≥3). Moreover, the HAS-BLED score should be reassessed at periodic intervals to address potentially modifiable bleeding risk factors because bleeding risks of AF patients are not static. When managing NOAC-related bleeding episodes, the possibility of occult malignancies (e.g., grastrointestinal [GI] tract cancers for patients experiencing GI bleeding and bladder cancer for patients with hematuria) should be kept in mind. Addressing all of these issues is crucial to achieving better clinical outcomes for anticoagulated AF patients. More efforts are necessary to incorporate clear and easy-to-follow recommendations about optimal management of anticoagulation into the guidelines to improve AF patient care.

Real-World Prevalence of Direct Oral Anticoagulant Off-Label Doses in Atrial Fibrillation: An Epidemiological Meta-Analysis

Background: The use of direct oral anticoagulant (DOAC) off-label doses in atrial fibrillation (AF) patients may result in poor clinical outcomes. However, the true prevalence remains scarce. This study aims at estimating the prevalence of DOAC off-label doses in AF patients.

Methods: Databases of MEDLINE, EMBASE, and COCHRANE were searched from inception through February 2020 for real-world studies that reported the off-label definition and prevalence data of AF patients using DOACs. The primacy outcomes were the overall prevalence of DOAC off-label doses and the corresponding underdose and overdose. The random-effects model was used for data synthesis. Variations on individual DOAC and different regions were examined by subgroup analyses.

Results: A total of 23 studies involving 162,474 AF patients were finally included. The overall prevalence of DOAC off-label doses was 24% (95% CI, 19–28%), with 18% for dabigatran, 27% for rivaroxaban, 24% for apixaban, and 26% for edoxaban. The prevalence of underdosed DOACs was 20% (95% CI, 16–24%) with significant difference among individual anticoagulants (13% for dabigatran, 22% for rivaroxaban, 22% for apixaban, and 18% for edoxaban; P_interaction=0.02). The prevalence of overdosed DOACs was 5% (95% CI, 3–7%), with the lowest prevalence observed in apixaban (2%). Subgroup analyses by regions demonstrated that the prevalence of DOAC off-label doses was higher in Asia (32%) than in North America (14%) and in Europe (22%), with underdose being predominant. Regardless of different regions, the prevalence of overdose was relatively low (4–6%).

Conclusion: This study provides an estimation of DOAC off-label doses in the real-world setting. The prevalence rate of DOAC off-label doses in AF patients was relatively high, with underdose being predominant. Clinicians in Asia preferred to prescribe underdose of DOACs to AF patients. More evidence about the appropriateness of DOAC off-label doses in AF patients is urgently needed. Education programs concerning the appropriate prescription of DOACs within the drug labels and accepted guidelines are necessary to DOAC prescribers to ensure the safety and effectiveness of anticoagulation therapy for patients with AF.

Dabigatran, rivaroxaban, and apixaban are superior to warfarin in Asian patients with non-valvular atrial fibrillation: An updated meta-analysis

BACKGROUND

Most of the randomized clinical trials that led to the wide use of non-vitamin K antagonist oral anticoagulants for stroke prevention in patients with atrial fibrillation (AF) originated from western countries.

AIM

To systematically review and quantitatively synthesize the real-world data regarding the efficacy and safety of dabigatran, rivaroxaban, and apixaban compared to warfarin for stroke prevention in Asian patients with non-valvular AF.

METHODS

Medline, Cochrane, and ClinicalTrial.gov databases were reviewed. A random-effect model meta-analysis was used and I-square was utilized to assess the heterogeneity. The primary outcome was ischemic stroke. The secondary outcomes were all-cause mortality, major bleeding, intracranial hemorrhage, and gastrointestinal bleeding.

RESULTS

Twelve studies from East Asia or Southeast Asia and 441450 patients were included. Dabigatran, rivaroxaban, and apixaban were associated with a significant reduction in the incidence of ischemic stroke [hazard ratio (HR) = 0.78, 95% confidence interval (CI): 0.65-0.94; HR = 0.79, 95%CI: 0.74-0.85, HR = 0.70, 95%CI: 0.62-0.78; respectively], all-cause mortality (HR = 0.68, 95%CI: 0.56-0.83; HR = 0.66, 95%CI: 0.52-0.84; HR = 0.66, 95%CI: 0.49-0.90; respectively), and major bleeding (HR = 0.61, 95%CI: 0.54-0.69; HR = 0.70, 95%CI: 0.54-0.90; HR = 0.58, 95%CI: 0.43-0.78; respectively) compared to warfarin.

CONCLUSION

Dabigatran, rivaroxaban, and apixaban appear to be superior to warfarin in both efficacy and safety in Asians with non-valvular AF.

Oral Anticoagulant Agents in Patients With Atrial Fibrillation and CKD: A Systematic Review and Pairwise Network Meta-analysis

OBJECTIVE

To evaluate the relative efficacy and safety of different oral anticoagulant agents (OACs) for patients with atrial fibrillation (AF) and chronic kidney disease (CKD).

STUDY DESIGN

Systematic review and pairwise and Bayesian network meta-analysis.

SETTING & STUDY POPULATIONS

Adult patients with AF and CKD stages 3-5D who received OACs.

SELECTION CRITERIA FOR STUDIES

Randomized controlled trials (RCTs) and observational studies that reported the efficacy and safety outcomes of subgroups with a glomerular filtration rate (GFR)<60mL/min.

DATA EXTRACTION

Two reviewers independently abstracted data, assessed study quality, and rated the strength of evidence (SOE).

ANALYTICAL APPROACH

Random-effects models using restricted maximum-likelihood methods were fit for the pairwise meta-analyses as well as a network meta-analysis within a Bayesian framework.

RESULTS

Pairwise meta-analysis including 8 RCTs and 46 observational studies showed that direct OACs (DOACs) were superior to warfarin in preventing thromboembolic events (hazard ratio [HR], 0.86 [95% CI, 0.78-0.95]), without heterogeneity (I²=10.5%), and in reducing the risk of bleeding events (HR, 0.81 [95% CI, 0.66-0.99]), with substantial heterogeneity (I²=69.8%), in patients with AF and a GFR of 15-60mL/min. Bayesian network meta-analysis including 8 RCTs showed that dose-adjusted apixaban and a 15-mg dose of edoxaban were superior to the other OAC regimens in reducing bleeding events. Dose-adjusted apixaban was more effective than edoxaban in preventing thromboembolic events for patients with AF and GFR in the range of 25-50 or 30-50mL/min. In dialysis recipients with AF, the use of OACs increased the risk of bleeding events by 28% (HR, 1.28 [95% CI, 1.03-1.60]) without significant beneficial effects versus not using anticoagulants.

LIMITATIONS

Low SOE and heterogeneity in most comparisons.

CONCLUSIONS

This study suggests that DOACs are superior to warfarin for the prevention of thromboembolic events and reduction in bleeding risk in patients with AF and mild to moderate kidney disease. However, the low SOE limits the conclusions that can be drawn about the preferred DOAC. Notably, the use of OACs may increase bleeding risk without significant benefits in dialysis recipients with AF.

REGISTRATION

Registered at PROSPERO with identification number CRD42018090896.

Sex and Racial Differences in Autopsy-Defined Causes of Presumed Sudden Cardiac Death

[Figure: see text].

Rationale and design of a prospective, multicenter, cross-sectional study of appropriateness evaluation of the prescription of non-vitamin K antagonist oral anticoagulants for Chinese atrial fibrillation patients (Chi-NOACs-AF trial)

BACKGROUND

Non-vitamin K antagonist oral anticoagulants (NOACs) are alternative to vitamin K antagonists (VKAs) for stroke prevention in patients with atrial fibrillation (AF). Along with their widespread clinical use in China, the off-label use of NOACs is commonly seen in real-world practice, which could result in adverse drug events and poor clinical outcomes. However, guideline adherence and label adherence for NOAC prescriptions have not been well evaluated in a real-world setting in China.

METHODS

Between January 2021 and June 2021, a total of 1,750 outpatients or inpatients with AF will be consecutively enrolled at 26 canters in China. Data on patient demographics, clinical characteristics, treatment strategies, and prescribing information related to anticoagulation therapy for patients with AF will be collected. Clinical pharmacists will evaluate the rationality of the anticoagulation regimens and NOAC prescriptions based on the guideline recommendations and drug labels that are approved by the National Medical Products Administration. The primary outcomes will be the prevalence of irrational anticoagulation strategies and the inappropriate NOAC prescriptions, as well as potential risk factors associated with inappropriate prescriptions in patients with AF.

DISCUSSION

This study will be the first national, multicenter, prospective study performed by pharmacists to explore real-world data on the appropriateness of NOAC prescription in Chinese patients with AF.

TRIAL REGISTRATION

The Chi-NOACs-AF trial (Trial number: ChiCTR2000035908).

Influence of PAR-1 in patients with non-valvular atrial fibrillation: The antiplatelet effect of dabigatran

INTRODUCTION

Dabigatran, a direct thrombin inhibitor, has been widely used in patients with non-valvular atrial fibrillation (NVAF) and is considered to have an antiplatelet effect. However, the mechanisms remain unclear. We evaluated protease-activated receptor-1 (PAR-1) expression and activation by thrombin on platelets from NVAF patients, before and after dabigatran treatment, in addition to the expression of platelet activation marker CD62P.

MATERIALS AND METHODS

The study included 18 NVAF patients. We used flow cytometry to measure the binding of PAR-1 monoclonal antibodies (SPAN12 and WEDE15) and the expression of CD62P with and without thrombin stimulation, before, 14 days after, and 28 days after treatment with dabigatran. Coagulation fibrinolysis markers were also measured.

RESULTS

PAR-1 expression was significantly lower in NVAF patients than in healthy controls (HC); it was further reduced by thrombin stimulation. CD62P expression was almost absent on the platelets in NVAF patients, but was significantly increased by thrombin stimulation. PAR-1 expression was not significantly different before and after treatment; CD62P expression was inhibited by dabigatran. The levels of coagulation markers were significantly higher in NVAF patients than in HC, and decreased after treatment.

CONCLUSIONS

Lower expression of PAR-1 in NVAF patients resulted from the cleavage of PAR-1 on some platelets, by exposure to small amounts of thrombin in vivo. The therapeutic effect of dabigatran in NVAF patients was demonstrated by inhibition of CD62P expression on the platelet upon thrombin stimulation in vitro. Our results indicate that dabigatran may reveal antithrombotic activity with antiplatelet and anticoagulant effects.

The efficacy and safety of Hirudin plus Aspirin versus Warfarin in the secondary prevention of Cardioembolic Stroke due to Nonvalvular Atrial Fibrillation: A multicenter prospective cohort study

Background: To investigate the efficacy and safety of hirudin plus aspirin therapy compared with warfarin in the secondary prevention of cardioembolic stroke due to nonvalvular atrial fibrillation (NVAF). Methods: Patients with cardioembolic stroke due to NVAF were prospectively enrolled from 18 collaborating hospitals from Dec 2011 to June 2015. Fourteen days after stroke onset, eligible patients were assigned to the hirudin plus aspirin group (natural hirudin prescribed as the traditional Chinese medicine Maixuekang capsule, 0.75 g, three times daily, combined with aspirin 100 mg, once daily) or the warfarin group (dose-adjusted warfarin targeting international normalized ratio (INR) 2-3, with an initial daily dose of 1.25 mg). Patients were followed up at 1, 2, 3, 6, 9, and 12 months after stroke onset. Time in therapeutic range (TTR) was calculated according to Rosendaal methodology to evaluate the quality of INR management in the warfarin group. The primary efficacy endpoint was the recurrence of stroke within 12 months after stroke onset. Safety was assessed as the occurrence of the composite event "intracranial hemorrhage and other bleeding events, death, and other serious adverse events". The Cox proportional hazard model and Kaplan-Meier curve were used to analyze the efficacy and safety events. Results: A total of 221 patients entered final analysis with 112 patients in the hirudin plus aspirin group and 109 in the warfarin group. Over the whole duration of our study, TTR for patients taking warfarin was 66.5 % ± 21.5%. A significant difference was not observed in the recurrence of stroke between the two groups (3.57% vs. 2.75%; P = 0.728). The occurrence of safety events was significantly lower in the hirudin plus aspirin group (2.68% vs.10.09%; P = 0.024). The risk for efficacy event was similar between the two groups (hazard ratio (HR), 1.30; 95% confidence interval (CI), 0.29-5.80). The safety risk was significantly lower in the hirudin plus aspirin group (HR, 0.27; 95% CI, 0.07-0.95). Kaplan-Meier analysis revealed significant difference in the temporal distribution in safety events (P = 0.023) but not in stroke recurrence (P = 0.726). Conclusion: Significant difference in efficacy was not detected between warfarin group and hirudin plus aspirin group. Compared with warfarin, hirudin plus aspirin therapy had lower safety risk in the secondary prevention of cardioembolic stroke due to NVAF.

The Risk of Gastrointestinal Bleeding between Non-Vitamin K Antagonist Oral Anticoagulants and Vitamin K Antagonists in the Asian Atrial Fibrillation Patients: A Meta-Analysis

Background: Non-vitamin K antagonist oral anticoagulants (NOACs) are more commonly used to prevent atrial fibrillation (AF) patients from thromboembolic events than vitamin K antagonists (VKAs). However, the gastrointestinal bleeding (GIB) risk in the Asian AF patients associated with NOACs in comparison with VKAs remained unaddressed. Materials and Methods: A systematic search of studies on NOACs and VKAs in the Asian AF patients was conducted in PubMed, Cochrane Library, and ClinicalTrials.gov. The primary outcome was the hazard ratio (HR) of any GIB associated with NOACs versus VKAs. The secondary outcome was the GIB risks in different kinds of NOACs compared with VKAs. Results: This meta-analysis included two randomized controlled trials (RCTs) and four retrospective studies, comprising at least 200,000 patients in total. A significantly lower HR of GIB risks was found in all kinds of NOACs than VKAs in the Asian AF patients (HR: 0.633; 95% confidence interval: 0.535-0.748; p < 0.001). Additionally, the GIB risks of different NOACs were apixaban (HR: 0.392), edoxaban (HR: 0.603), dabigatran (HR: 0.685), and rivaroxaban (HR: 0.794), respectively. Conclusions: NOACs significantly reduced the risk of GIB in the Asian AF patients compared with VKAs. In the four NOACs compared with VKAs, apixaban probably had a trend of the least GIB risk. We need further head-to-head studies of different NOACs to confirm which NOAC is the most suitable for Asian AF patients and to know the optimal dosage regimen of different NOACs.

The risk of stroke/systemic embolism and major bleeding in Asian patients with non-valvular atrial fibrillation treated with non-vitamin K oral anticoagulants compared to warfarin: Results from a real-world data analysis

BACKGROUND

Although randomized trials provide a high level of evidence regarding the efficacy of non-vitamin K oral anticoagulants (NOACs), the results of such trials may differ from those observed in day-to-day clinical practice.

AIMS

To compare the risk of stroke/systemic embolism (S/SE) and major bleeding (MB) between NOAC and warfarin in clinical practice.

METHODS

Patients with non-valvular atrial fibrillation (NVAF) who started warfarin/NOACs between January 2015 and November 2016 were retrospectively identified from Korea's nationwide health insurance claims database. Using inpatient diagnosis and imaging records, the Cox models with inverse probability of treatment weighting using propensity scores were used to estimate hazard ratios (HRs) for NOACs relative to warfarin.

RESULTS

Of the 48,389 patients, 10,548, 11,414, 17,779 and 8,648 were administered apixaban, dabigatran, rivaroxaban and warfarin, respectively. Many patients had suffered prior strokes (36.7%, 37.7%, 31.4%, and 32.2% in apixaban, dabigatran, rivaroxaban, and warfarin group, respectively), exhibited high CHA2DS2-VASc (4.8, 4.6, 4.6, and 4.1 in apixaban, dabigatran, rivaroxaban, and warfarin group, respectively) and HAS-BLED (3.7, 3.6, 3.6, and 3.3 in apixaban, dabigatran, rivaroxaban, and warfarin group, respectively) scores, had received antiplatelet therapy (75.4%, 75.7%, 76.8%, and 70.1% in apixaban, dabigatran, rivaroxaban, and warfarin group, respectively), or were administered reduced doses of NOACs (49.8%, 52.9%, and 42.8% in apixaban, dabigatran, and rivaroxaban group, respectively). Apixaban, dabigatran and rivaroxaban showed a significantly lower S/SE risk [HR, 95% confidence intervals (CI): 0.62, 0.54-0.71; 0.60, 0.53-0.69; and 0.71, 0.56-0.88, respectively] than warfarin. Apixaban and dabigatran (HR, 95% CI: 0.58, 0.51-0.66 and 0.75, 0.60-0.95, respectively), but not rivaroxaban (HR, 95% CI: 0.84, 0.69-1.04), showed a significantly lower MB risk than warfarin.

CONCLUSIONS

Among Asian patients who were associated with higher bleeding risk, low adherence, and receiving reduced NOAC dose than that provided in randomised controlled trials, all NOACs were associated with a significantly lower S/SE risk and apixaban and dabigatran with a significantly lower MB risk than warfarin.

Non-Vitamin K Antagonist Oral Anticoagulants in Secondary Stroke Prevention in Atrial Fibrillation Patients: An Updated Analysis by Adding Observational Studies

BACKGROUND

This meta-analysis aimed to evaluate the efficacy and safety of non-vitamin K antagonist oral anticoagulants (NOACs) versus vitamin K antagonists (VKAs) in secondary stroke prevention in atrial fibrillation (AF) patients.

METHODS

PubMed and Embase electronic databases were systematically searched from January 2009 to July 2019 for relevant randomized clinical trials and observational studies. A random-effects model was applied in the pooled analysis.

RESULTS

A total of 14 studies (4 randomized clinical trials and 10 observational studies) were included. Based on the randomized clinical trials, compared with VKA use, the use of NOACs was associated with decreased risk of stroke and systemic embolism, major bleeding, and intracranial bleeding. Based on the observational studies, compared with VKAs, the subgroup analysis showed that dabigatran and rivaroxaban were associated with a reduced risk of stroke or systemic embolism, whereas dabigatran and apixaban were associated with a decreased risk of major bleeding.

CONCLUSION

Based on current data, the use of NOACs is at least non-inferior to the use of VKAs in AF patients for secondary stroke prevention irrespective of NOAC type.

Association between platelet count and the risk of bleeding among patients with nonvalvular atrial fibrillation taking dabigatran after radiofrequency ablation: a cohort study

Background

A reduction in platelet count or function can be a risk factor for bleeding in anticoagulated patients. However, the association between platelet count and the risk of bleeding among nonvalvular atrial fibrillation (NVAF) patients taking dabigatran remains unclear. The aim of this study was to investigate the relationship between platelet count and the risk of bleeding among patients with NVAF taking dabigatran after radiofrequency ablation.

Methods

In this multicenter, prospective and observational study, a total of 576 NVAF patients treated with dabigatran (110 mg bid) after radiofrequency ablation were recruited from 12 centers in China from February 2015 to December 2017. All patients were followed for 3 months. The association between platelet count and the risk of bleeding was evaluated by Cox proportional hazards regression analysis. To explore the nonlinearity between platelet count and bleeding, we used a Cox proportional hazards regression model with cubic spline functions and smooth curve fitting and a two-piecewise Cox proportional hazards model.

Results

During a median follow-up duration of 87 days, 50 patients experienced bleeding events. Overall, there was an inverse relationship between the risk of bleeding and platelet count. Low platelet count (<100×10⁹/L) were associated with an increased risk of bleeding [hazard ratio (HR), 4.05; 95% confidence interval (CI): 1.32-12.46] compared to normal counts. The adjusted smooth curve showed a nonlinear relationship between platelet count and bleeding events. The inflection point of the platelet count was 105×10⁹/L. For platelet counts <105×10⁹/L, the HR (95% CI) was 0.89 (0.84-0.95), and for platelet counts ≥105×10⁹/L, the HR (95% CI) was 1.01 (0.95-1.08).

Conclusions

Low platelet counts were associated with an increased risk for bleeding among patients with NVAF taking dabigatran after catheter ablation.

Real-World Comparative Effectiveness and Safety of Non-Vitamin K Antagonist Oral Anticoagulants vs. Warfarin in a Developing Country

We aimed to compare effectiveness and safety of the non-vitamin K antagonist oral anticoagulants (NOACs) vs. warfarin for stroke prevention in nonvalvular atrial fibrillation (NVAF) in a developing country where anticoagulation control with warfarin is suboptimal. A real-world study was conducted among patients with NVAF in Thailand receiving NOACs and warfarin from 9 hospitals during January 2012 to April 2018. Propensity-score weighting was used to balance covariates across study groups. Cox regression models were used to compare the risk of thromboembolism, major bleeding, and net adverse clinical events across matched cohorts. A total of 2,055 patients; 605, 604, 441, and 405 patients receiving warfarin, rivaroxaban, dabigatran, and apixaban, respectively, were included. Median (interquartile range) time in therapeutic range (TTR) for warfarin users was 49.5% (26.6%-70.3%). Compared with warfarin, NOACs were associated with a significant reduction in major bleeding either when analyzed as a group (adjusted hazard ratio (HR) (95% confidence interval (CI)) of 0.46 (0.34-0.62) or by each agent. Compared with warfarin users with poor TTR, apixaban (adjusted HR 0.48, 95% CI 0.26-0.86, P = 0.013) and dabigatran (adjusted HR 0.44, 95% CI 0.21-0.90, P = 0.025) were associated with a lower risk of thromboembolism, in addition to markedly lower risk of major bleeding. In a healthcare system where anticoagulation control with warfarin is suboptimal, use of NOACs was associated with a profound reduction in major bleeding. The effectiveness and safety advantages of NOACs were more pronounced compared with warfarin users with low TTR.

Non-vitamin K antagonist oral anticoagulants in very elderly east Asians with atrial fibrillation: A nationwide population-based study

BACKGROUND

The evidence of effectiveness and safety of the non-vitamin K antagonist oral anticoagulants (NOACs) among elderly East Asians is limited.

OBJECTIVES

We aimed to describe the effectiveness and safety outcomes associated with NOACs and warfarin among elderly Koreans aged ≥80 years.

METHODS

Using the Korean Health Insurance Review and Assessment service database, patients with atrial fibrillation (AF) who were naïve to index oral anticoagulant between 2015 and 2017 were included in this study (20,573 for NOACs and 4086 for warfarin). Two treatment groups were balanced using the inverse probability of treatment weighting (IPTW) method. The clinical outcomes including ischemic stroke, major bleeding including intracranial hemorrhage (ICH) and gastrointestinal bleeding (GIB), and a composite of these outcomes were evaluated.

RESULTS

Compared to warfarin, NOACs were associated with lower risks of ischemic stroke (hazard ratio 0.74 [95% confidence interval 0.62-0.89]), and composite outcome (0.78 [0.69-0.90]). NOACs showed nonsignificant trends towards to lower risks of GIB and major bleeding than warfarin. The risk of ICH of NOAC group was comparable with the warfarin group. Among NOACs, apixaban and edoxaban showed better composite outcomes than warfarin. Among the clinical outcomes, only ischemic stroke and the composite outcome had a significant interaction with age subgroups (80-89 years and ≥90 years, P-for-interaction = .097 and .040, respectively).

CONCLUSION

NOACs were associated with lower risks of ischemic stroke and the composite outcome (ischemic stroke and major bleeding) compared to warfarin in elderly East Asians. Physicians should be more confident in prescribing NOACs to elderly East Asians with AF.

Chromosomal abnormalities and atrial fibrillation and ischemic stroke incidence: a nationwide population-based study

There is a paucity of information as to whether chromosomal abnormalities, including Down Syndrome, Turner Syndrome, and Klinefelter Syndrome, have an association with atrial fibrillation (AF) and ischemic stroke development. Data from 3660 patients with Down Syndrome, 2408 with Turner Syndrome, and 851 with Klinefelter Syndrome without a history of AF and ischemic stroke were collected from the Korean National Health Insurance Service (2007–2014). These patients were followed-up for new-onset AF and ischemic stroke. Age- and sex-matched control subjects (at a ratio of 1:10) were selected and compared with the patients with chromosomal abnormalities. Down Syndrome patients showed a higher incidence of AF and ischemic stroke than controls. Turner Syndrome and Klinefelter Syndrome patients showed a higher incidence of AF than did the control group, but not of stroke. Multivariate Cox regression analysis revealed that three chromosomal abnormalities were independent risk factors for AF, and Down Syndrome was independently associated with the risk of stroke. In conclusion, Down Syndrome, Turner Syndrome, and Klinefelter Syndrome showed an increased risk of AF. Down Syndrome patients only showed an increased risk of stroke. Therefore, AF surveillance and active stroke prevention would be beneficial in patients with these chromosomal abnormalities.

Real-world Comparisons of Direct Oral Anticoagulants for Stroke Prevention in Asian Patients with Non-valvular Atrial Fibrillation: a Systematic Review and Meta-analysis

BACKGROUND

Whether four direct oral anticoagulants (DOACs) are superior to warfarin among Asians with non-valvular atrial fibrillation (NVAF) remains unclear in the real-world setting.

METHODS

We searched PubMed and Medline + Journals@Ovid + EMBASE from September 17, 2009 to May 4, 2019 to perform a systematic review and meta-analysis of all observational real-world studies comparing four DOACs with warfarin specifically focused on Asian patients with NVAF.

RESULTS

From the original 212 results retrieved, 18 studies were included in the meta-analysis. Overall, DOACs were associated with lower risks of thromboembolism (hazard ratio; [95% confidence interval], 0.70; [0.63-0.78]), acute myocardial infarction (0.67; [0.57-0.79]), all-cause mortality (0.62; [0.56-0.69]), major bleeding (0.59; [0.50-0.69]), intracranial hemorrhage (0.50; [0.40-0.62]), gastrointestinal bleeding (0.66; [0.46-0.95]), and any bleeding (0.82; [0.73-0.92]) than warfarin. There was statistic heterogeneity between DOACs for the risks of thromboembolism (P interaction = 0.03) and acute myocardial infarction (P interaction = 0.007) when compared to warfarin. However, all DOACs showed lower risks of thromboembolism and acute myocardial infarction than warfarin when pooling studies that compared individual DOAC with warfarin. With regard to the other outcomes when compared to warfarin, there was no statistical heterogeneity between DOACs. In addition, the effectiveness and safety of four DOACs versus warfarin persisted in the subgroups of either standard-dose or low-dose DOACs.

CONCLUSIONS

The meta-analysis shows that the DOACs had greater effectiveness and safety compared to warfarin in real-world practice for stroke prevention, among Asian patients with NVAF.