Oral anticoagulants for Asian patients with atrial fibrillation

A Real-World, Prospective, Observational Study of Rivaroxaban on Prevention of Stroke and Non-Central Nervous Systemic Embolism in Renally Impaired Korean Patients With Non-Valvular Atrial Fibrillation: XARENAL

BACKGROUND AND OBJECTIVES

Several real-world studies have been done in patients with nonvalvular atrial fibrillation (NVAF); however, information on its safety profile in patients with renal impairment is limited. XARENAL, a real-world study, aimed to prospectively investigate the safety profile of rivaroxaban in patients with NVAF with renal impairment (creatinine clearance [CrCl], 15-49 mL/min).

METHODS

XARENAL is an observational single-arm cohort study in renal impairment NVAF patients. Patients were followed up approximately every 3 months for 1 year or until 30 days following early discontinuation. The primary endpoint was major bleeding events. All adverse events, symptomatic thromboembolic events, treatment duration, and renal function change from baseline were the secondary endpoints.

RESULTS

XARENAL included 888 patients from 29 study sites. Overall, 713 (80.3%) had moderate renal impairment (CrCl, 30-49 mL/min), and 175 (19.7%) had severe renal impairment (CrCl, 15-29 mL/min) with a mean estimated glomerular filtration rate (eGFR) of 45.2±13.0 mL/min/1.73 m². The mean risk scores were 3.3±1.4 and 1.7±0.9 for CHA₂DS₂-VASc score and HAS-BLED score, respectively. An incidence proportion of 5.6% (6.2 events per 100 patient-years) developed major bleeding; however, fatal bleeding occurred in 0.5% (0.5 events per 100 patient-years). The mean change in the eGFR was 2.22±26.47 mL/min/1.73 m² per year.

CONCLUSIONS

XARENAL observed no meaningful differences in major bleeding events from other previous findings as well as renal function changes in rivaroxaban-treated NVAF patients with renal impairment, which is considered to be acceptable in clinical practice.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03746301.

Comparison of oral anticoagulants for stroke prevention in atrial fibrillation using the UK clinical practice research Datalink Aurum: A reference trial (ARISTOTLE) emulation study

BACKGROUND

Stroke prevention guidance for patients with atrial fibrillation (AF) uses evidence generated from randomised controlled trials (RCTs). However, applicability to patient groups excluded from trials remains unknown. Real-world patient data provide an opportunity to evaluate outcomes in a trial analogous population of direct oral anticoagulants (DOACs) users and in patients otherwise excluded from RCTs; however, there remains uncertainty on the validity of methods and suitability of the data. Successful reference trial emulation can support the generation of evidence around treatment effects in groups excluded or underrepresented in trials. We used linked United Kingdom primary care data to investigate whether we could emulate the pivotal ARISTOTLE trial (apixaban versus warfarin) and extend the analysis to investigate the impact of warfarin time in therapeutic range (TTR) on results.

METHODS AND FINDINGS

Patients with AF in the UK Clinical Practice Research Datalink (CPRD Aurum) prescribed apixaban or warfarin from 1 January 2013 to 31 July 2019 were selected. ARISTOTLE eligibility criteria were applied to this population and matched to the RCT apixaban arm on baseline characteristics creating a trial-analogous apixaban cohort; this was propensity-score matched to warfarin users in the CPRD Aurum. ARISTOTLE outcomes were assessed using Cox proportional hazards regression stratified by prior warfarin exposure status during 2.5 years of patient follow-up and results benchmarked against the trial results before treatment effectiveness was further evaluated based on (warfarin) TTR. The dataset comprised 8,734 apixaban users and propensity-score matched 8,734 warfarin users. Results [hazard ratio (95% confidence interval)] confirmed apixaban noninferiority for stroke or systemic embolism (SE) [CPRD 0.98 (0.82,1.19) versus trial 0.79 (0.66,0.95)] and death from any cause [CPRD 1.03 (0.93,1.14) versus trial 0.89 (0.80,0.998)] but did not indicate apixaban superiority. Absolute event rates for stroke/SE were similar for apixaban in CPRD Aurum and ARISTOTLE (1.27%/year), whereas a lower event rate was observed for warfarin (CPRD Aurum 1.29%/year, ARISTOTLE 1.60%/year). Analysis by TTR suggested similar effectiveness of apixaban compared with poorly controlled warfarin (TTR < 0.75) for stroke/SE [0.91 (0.73, 1.14)], all-cause death [0.94 (0.84, 1.06)], and superiority for major bleeding [0.74 (0.63, 0.86)]. However, when compared with well-controlled warfarin (TTR ≥ 0.75), apixaban was associated with an increased hazard for all-cause death [1.20 (1.04, 1.37)], and there was no significant benefit for major bleeding [1.08 (0.90, 1.30)]. The main limitation of the study's methodology are the risk of residual confounding, channelling bias and attrition bias in the warfarin arm, and selection bias and misclassification in the analysis by TTR.

CONCLUSIONS

Analysis of noninterventional data generated results demonstrating noninferiority of apixaban versus warfarin consistent with prespecified benchmarking criteria. Unlike in ARISTOTLE, superiority of apixaban versus warfarin was not seen, possible due to the lower proportion of Asian patients and higher proportion of patients with well-controlled warfarin compared to ARISTOTLE. This methodological template can be used to investigate treatment effects of oral anticoagulants in patient groups excluded from or underrepresented in trials and provides a framework that can be adapted to investigate treatment effects for other conditions.

Analysis of the current status of "pseudo" unplanned endotracheal extubation in ICU patients in China's tertiary hospitals

To analyze the current status of "pseudo" unplanned endotracheal extubation in ICU patients in China's tertiary hospitals and to provide a reference for improving the quality of medical care. Through the National Nursing Quality Data Platform, unplanned endotracheal extubation data reported by ICUs in China's tertiary hospitals from 2019 to 2022 were analyzed. The situation of reported hospitals, causes, and the current status of "pseudo" unplanned endotracheal extubation in ICU patients was analyzed. The indicator of unplanned endotracheal extubation in ICUs of China's tertiary hospitals is mainly from first-class tertiary hospitals (74.9%), most of which are self-extractions by patients (74.6%). The proportion of "pseudo" unplanned endotracheal extubation is 45.1%. "Pseudo" unplanned endotracheal extubation is common in the ICUs of China's tertiary hospitals. As such, management blind spots deserve attention from managers and clinical staff.

Sex-related differences in presentation, treatment, and outcomes of Asian patients with atrial fibrillation: a report from the prospective APHRS-AF Registry

We aimed to investigate the sex-related differences in the clinical course of patients with Atrial Fibrillation (AF) enrolled in the Asia-Pacific-Heart-Rhythm-Society Registry. Logistic regression was utilized to investigate the relationship between sex and oral anticoagulant, rhythm control strategies and the 1-year chance to maintain sinus rhythm. Cox-regression was utilized to assess the 1-year risk of all-cause, and cardiovascular death, thromboembolic events, acute coronary syndrome, heart failure, and major bleeding. In the whole cohort (4121 patients, 69 ± 12 years,34.3% female), females had different cardiovascular risk factors, clinical manifestations, and disease perceptions than men, with more advanced age (72 ± 11 vs 67 ± 12 years, p < 0.001) and dyslipidemia (36.7% vs 41.7%, p = 0.002). Coronary artery disease was more prevalent in males (21.1% vs 16.1%, p < 0.001) as well as the use of antiplatelet drugs. Females had a higher use of oral anticoagulant (84.9% vs 81.3%, p = 0.004) but this difference was non-significant after adjustment for confounders. On multivariable analyses, females were less often treated with rhythm control strategies (Odds Ratio [OR] 0.44,95% Confidence Interval [CI] 0.38-0.51) and were less likely to maintain sinus rhythm (OR 0.27, 95% CI 0.22-0.34) compared to males. Cox-regressions analysis showed no sex-related differences for the risk of death, cardiovascular, and bleeding. The clinical management of Asian AF patients should consider several sex-related differences.

The Distribution of the Genotypes of ABCB1 and CES1 Polymorphisms in Kazakhstani Patients with Atrial Fibrillation Treated with DOAC

Nowadays, direct oral anticoagulants (DOACs) are the first-line anticoagulant strategy in patients with non-valvular atrial fibrillation (NVAF). We aimed to identify the influence of polymorphisms of the genes encoding P-glycoprotein (ABCB1) and carboxylesterase 1 (CES1) on the variability of plasma concentrations of DOACs in Kazakhstani patients with NVAF. We analyzed polymorphisms rs4148738, rs1045642, rs2032582 and rs1128503 in ABCB1 and rs8192935, rs2244613 and rs71647871 CES1 genes and measured the plasma concentrations of dabigatran/apixaban and biochemical parameters in 150 Kazakhstani NVAF patients. Polymorphism rs8192935 in the CES1 gene (p = 0.04), BMI (p = 0.01) and APTT level (p = 0.01) were statistically significant independent factors of trough plasma concentration of dabigatran. In contrast, polymorphisms rs4148738, rs1045642, rs2032582 and rs1128503 in ABCB1 and rs8192935, rs2244613 and rs71647871 CES1 genes did not show significant influence on plasma concentrations of dabigatran/apixaban drugs (p > 0.05). Patients with GG genotype (138.8 ± 100.1 ng/mL) had higher peak plasma concentration of dabigatran than with AA genotype (100.9 ± 59.6 ng/mL) and AG genotype (98.7 ± 72.3 ng/mL) (Kruskal-Wallis test, p = 0.25). Thus, CES1 rs8192935 is significantly associated with plasma concentrations of dabigatran in Kazakhstani NVAF patients (p < 0.05). The level of the plasma concentration shows that biotransformation of the dabigatran processed faster in individual carriers of GG genotype rs8192935 in the CES1 gene than with AA genotype.

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.

Evolving Antithrombotic Treatment Patterns for Patients With Nonvalvular Atrial Fibrillation and Acute Coronary Syndrome or Underwent Percutaneous Coronary Intervention in China: A Cross-Sectional Study

Objective

Antithrombotic therapy in patients with nonvalvular atrial fibrillation (NVAF) concomitant with the acute coronary syndrome (ACS) or underwent percutaneous coronary intervention (PCI) is challenging and has evolved in recent years. However, real-world data on this issue about antithrombotic regimens at discharge and its evolving trend were relatively scarce, especially in China.

Methods

A total of 2,182 patients with NVAF and ACS/PCI were enrolled from 2017 to 2019. A total of 1,979 patients were finally analyzed and divided in three sequential cohorts: cohort 1 (2017), n = 674; cohort 2 (2018), n = 793; and cohort 3 (2019), n = 512. Baseline characteristics and antithrombotic therapy at discharge were analyzed by cohort.

Results

In our cross-sectional study, the majority of patients (59.6%) received dual antiplatelet therapy (DAPT). Over the 3 years, DAPT prescription reduced from nearly 70% to <50% (P trend < 0.001), while triple therapy (TT)/double therapy (DT) increased from 27.2 to 50.0% (P trend < 0.001). This trend was also seen in different subgroups stratified by CHA2DS2-VASc score, HAS-BLED score, coronary artery disease type, or management type, and was validated after multivariate adjustment. Persistent atrial fibrillation and history of congestive heart failure, hypertension, diabetes mellitus, and stroke/transient ischemic attack/systemic embolism were the independent predictors of TT/DT use, while ACS, PCI, or advanced chronic kidney disease was related with more DAPT prescription.

Conclusion

There is a shift of antithrombotic regime at discharge for patients with NVAF with recent ACS/PCI with reducing DAPT prescription and increasing TT/DT prescription. While the appropriate antithrombotic regimen for patients with NVAF having ACS/PCI is still underused in China.

Changes of antithrombotic prescription in atrial fibrillation patients with acute coronary syndrome or percutaneous coronary intervention and the subsequent impact on long-term outcomes: a longitudinal cohort study

OBJECTIVES

The choice of optimal antithrombotic therapy in atrial fibrillation (AF) patients with acute coronary syndrome (ACS) or percutaneous coronary intervention (PCI) remains controversial. The aim of this longitudinal cohort study is to investigate the prescribing pattern of antithrombotic regimen in different cohorts and its subsequent impact.

SETTING AND DESIGN

Longitudinal data from the Tri-Service General Hospital-Coronary Heart Disease (TSGH-CHD) registry, between January 2016 and August 2018 was screened.

PARTICIPANTS AND METHOD

Patients with prior history of nonvalvular AF, who had ACS presentation or underwent PCI were selected, and these patients were divided into cohort 1 and cohort 2, according to the index date of antithrombotic prescription before and after the PIONEER AF-PCI study.

PRIMARY AND SECONDARY OUTCOMES

The primary safety endpoints were composites of major bleeding and/or clinically relevant non-major bleeding. The secondary efficacy endpoints included the occurrence of all-cause mortality, stroke/systemic embolization, nonfatal myocardial infarction (MI), and >30-days coronary revascularization.

RESULTS

A total of 121 patients were included into analysis (cohort 1=35; cohort 2=86). Comparing with cohort 1, the prescription rate of triple antithrombotic therapy (TAT) increased from 17.1 to 38.4%, especially the regimen with dual antiplatelet therapy (DAPT) plus low-dose non-vitamin-K dependent oral anticoagulation (NOAC). However, the prescription rate of dual antithrombotic therapy (DAT) decreased (14.3-10.5%), as well as the prescription rate of DAPT (68.6-51.2%). These changes of antithrombotic prescription across different cohorts were not associated with risk of adverse safety (HR= 0.87; 95% CI, 0.42-1.80, p=0.710) and efficacy outcomes (HR=0.96; 95% CI, 0.40-2.32, p=0.930).

CONCLUSIONS

Entering the NOAC era, the prescription of TAT increased alongside the decrease in DAT. As the prescription rate of DAPT without anticoagulation remained high, future efforts are mandatory to improve the implementation of guidelines and clinical practice.

What is Standard Dose of Rivaroxaban in Elderly Asian Patients with Atrial Fibrillation: 20ms versus. 15mg?

Although there is no age criterion for rivaroxaban dose reduction, elderly patients with atrial fibrillation (AF) are often prescribed an off-label reduced dose. We aimed to evaluate whether age is a necessary criterion for rivaroxaban dose reduction in Korean patients with AF. Among 2208 patients who prescribed warfarin or rivaroxaban, 552 patients over 75 years without renal dysfunction (creatinine clearance >50 mL/min) were compared based on propensity score matching. The rivaroxaban group was further divided into a 20 mg (R20; on-label) and a 15 mg (R15; off-label). Primary net clinical benefit (NCB) was defined as the composite of stroke, systemic embolism, major bleeding, and all-cause mortality. Secondary NCB was defined as the composite of stroke, systemic embolism, and major bleeding. Patients were followed for 1 year, or until the first outcome occurrence. Both rivaroxaban groups had comparable efficacy compared with warfarin. However, both R20 (0.9% vs 7.4%, p = .014) and R15 (2.3% vs 7.4%, p = .018) had a significant reduction in major bleeding. There were no differences in efficacy or safety outcomes between R20 and R15. R20 had significantly reduced primary (hazard ratio [HR] 0.33, 95% confidence interval [CI]: 0.12–0.93) and secondary (HR 0.31, 95% CI: 0.10–0.93) NCBs compared with warfarin. However, primary and secondary NCBs were not reduced in R15. In real-world practice with elderly patients with AF, off-label rivaroxaban dose reduction to 15 mg conferred no benefits. Therefore, guideline-adherent rivaroxaban 20 mg is favorable in elderly Korean patients with AF.

Risk of major bleeding and thromboembolism in Asian patients with nonvalvular atrial fibrillation using direct oral anticoagulants versus warfarin

Background Bleeding and thromboembolism prevention is important in patients with nonvalvular atrial fibrillation receiving anticoagulants, including direct oral anticoagulants and warfarin. Asians have higher risks of bleeding complications when taking anticoagulants. However, evidence that considers laboratory parameters is lacking. Objective We aimed to compare the safety and effectiveness between direct oral anticoagulants and warfarin in Asian patients with nonvalvular atrial fibrillation. Setting Retrospective design using hospital-based data. Method This propensity score-matched cohort study included data extracted from the electronic medical records of the En Chu Kong Hospital Research Database. Main outcome measure Outcome measures were major bleeding and thromboembolism. Cox proportional hazard models were applied for evaluating hazard ratios with 95% confidence intervals. Results Among 1075 patients with nonvalvular atrial fibrillation, 687 and 388 were administered direct oral anticoagulants and warfarin, respectively. After propensity score matching, 264 patient pairs were selected. Compared with warfarin use, direct oral anticoagulant use was associated with similar risks for major bleeding and thromboembolism; however, the latter was associated with increased gastrointestinal bleeding risks (adjusted hazard ratio 3.59; 95% confidence interval, 1.31-11.39). Notably, an approximately 10 fold increased risk of gastrointestinal bleeding was observed in 0-6 month direct oral anticoagulant users (adjusted hazard ratio 10.13, 95% confidence interval 1.27-80.89). Conclusion Direct oral anticoagulant use was not associated with major bleeding and thromboembolism occurrence in Asian patients with nonvalvular atrial fibrillation. However, direct oral anticoagulant use was associated with increased gastrointestinal bleeding risks, especially when used within 0-6 months of direct oral anticoagulant use.

A prospective, observational study of rivaroxaban for stroke prevention in atrial fibrillation: the XANAP Korea

BACKGROUND/AIMS

Atrial fibrillation (AF)-related stroke accounts for 20% of ischemic strokes. Rivaroxaban use in AF patients for preventing stroke and systemic embolism was approved in 2013 in Korea. This study was to investigate the safety and effectiveness of rivaroxaban use in Korean patients with non-valvular AF in a real-world setting.

METHODS

This was an analysis of the Korean patients in Xarelto for Prevention of Stroke in Patients with Atrial Fibrillation in Asia-Pacific (XANAP), which was a prospective, observational cohort study including patients with non-valvular AF starting rivaroxaban treatment to prevent stroke or non-central nervous system systemic embolism (non-CNS SE), conducted in 10 Asian countries.

RESULTS

A total of 844 patients were enrolled in the Korean portion of the XANAP study. In XANAP Korea, the mean age was 70.1 years and 62.6% were males. The mean CHADS2 score was 2.5 and the mean CHA2DS2-VASc score was 3.8. 47% of the patients had experienced prior stroke or non-CNS SE or transient ischemic attack. 73.6% of the patients had CHADS2 score ≥ 2. Incidence proportions of 0.8% of the patients (1.1 per 100 patient-years) developed adjudicated treatment-emergent major bleeding. Death was observed in 1.2% of the patients. The incidence of non-major bleeding as well as thromboembolic event were 8.4% (11.6 per 100 patient-years) and 1.5% (2.0 per 100 patient-years), respectively.

CONCLUSION

This study reaffirmed the consistent safety profile of rivaroxaban. We found consistent results with overall XANAP population for rivaroxaban in terms of safety in non-valvular AF patients for the prevention of stroke and non-CNS SE.

CHA2DS2-VASc Score for Identifying Patients at High Risk of Postoperative Atrial Fibrillation After Cardiac Surgery: A Meta-analysis

BACKGROUND

Postoperative atrial fibrillation (POAF) is a common complication after cardiac surgery, resulting in an increased risk of morbidity and longer hospital stay. Pharmacologic prophylaxis has been recommended to improve the outcome in patients at high risk of developing POAF after cardiac surgery. Several studies have applied the CHA₂DS₂-VASc (Congestive heart failure, Hypertension Age [≥65 = 1 point, ≥75 = 2 points], Diabetes, and Stroke/transient ischemic attack (2 points)-vascular disease [peripheral arterial disease, previous myocardial infarction, aortic atheroma]) score in the risk stratification of POAF but yielded contradicting results. This study aims to determine the association between CHA₂DS₂-VASc score and POAF and further to explore its discriminative ability for the prediction of POAF.

METHODS

We systematically searched the Medline, Embase, Cochrane library, and other data sources with key terms "CHA₂DS₂-VASc," "atrial fibrillation," and "cardiac surgery." Studies designed for CHA₂DS₂-VASc score in stratifying the risks of POAF in patients undergoing cardiac surgery were included. Statistical analyses were performed with R 3.5.1 and STATA 13.0.

RESULTS

Seven hundred twenty-one studies were identified, of which 12 studies with 18,086 patients were finally included in our analysis. The CHA₂DS₂-VASc score was found to be an independent predictor of POAF after cardiac surgery (odds ratio, 1.46; 95% confidence interval [CI], 1.25-1.72) and exhibited a relatively strong specificity (0.70; 95% CI, 0.61-0.78) and sensitivity (0.72; 95% CI, 0.54-0.85) for predicting POAF. The bivariate model-based pooled area under the receiver operating curve was estimated to be 0.76 (95% CI, 0.72-0.79).

CONCLUSIONS

The CHA₂DS₂-VASc score has relatively good performance in predicting POAF after cardiac surgery and may help identify the patients at high risk of POAF.

Comparative Effectiveness and Safety of Antithrombotic Therapy in Atrial Fibrillation Patients Presenting with Acute Coronary Syndrome or Percutaneous Coronary Intervention

BACKGROUND

There remains insufficient evidence to determine the optimal antithrombotic strategy in atrial fibrillation (AF) patients presenting with acute coronary syndrome (ACS) or percutaneous coronary interventions (PCIs), especially in Asian populations.

OBJECTIVES

This study aimed to examine the real-world patterns of antithrombotic treatment among these patients and to compare the effectiveness and safety of different antithrombotic regimens.

METHODS

A retrospective cohort study was conducted in AF patients presenting with a new ACS or PCI during 2006/1/1-2016/4/1. Three antithrombotic regimens were compared: dual antiplatelet therapy (DAPT, as the reference group), triple therapy (TT: DAPT plus an oral anticoagulant), and dual therapy (DT: single antiplatelet plus an oral anticoagulant). The outcomes of interest were major adverse cardiac and cerebrovascular events (MACCEs) and bleeding. Treatment effect was estimated using a Cox proportional hazards model. Inverse probability of treatment weighting was used to balance baseline characteristics among comparison groups.

RESULTS

Overall, 532 patients were included. At discharge from the index hospitalization, DAPT was the most common antithrombotic therapy, followed by TT and DT. No significant difference in MACCEs was found among the different antithrombotic regimens. However, DT was associated with a lower risk of any bleeding [adjusted hazard ratio 0.20 (95% confidence interval, 0.06-0.75)] than DAPT.

CONCLUSIONS

In the study population, DAPT was the most commonly prescribed antithrombotic regimen for cardio-cerebrovascular disease prevention. The effectiveness outcomes were comparable across different antithrombotic strategies. The lower risk of bleeding with DT compared with DAPT warrants further investigation.

Preventable Cases of Oral Anticoagulant-Induced Bleeding: Data From the Spontaneous Reporting System

Background

Despite the risk of bleeding is a well-known adverse effect of oral anticoagulants, there is scarce evidence on the preventability of oral anticoagulant-induced bleedings. Therefore, we investigated the potential risk factors related to preventable cases of oral anticoagulant-induced bleedings.

Methods

We performed a study using Individual Case Safety Reports (ICSRs) with an oral anticoagulant as suspected drug among those reported through the spontaneous reporting system of Campania Region from 1 July 2012 to 31 December 2017. The P-method was used for the preventability assessment of all cases of bleeding.

Results

In total, 58 cases out of 253 (22.9%) were preventable, and the most reported suspected drug was an indirect oral anticoagulant (warfarin). Sixty-eight critical criteria for preventability were identified, all related to healthcare professionals' practices. The most detected risk factor related to healthcare professionals' practices was the labeled drug-drug interaction for both direct and indirect oral anticoagulants.

Conclusion

Our findings describe the most reported risk factors for preventability of oral anticoagulant-induced bleedings. These factors may be useful for targeting interventions to improve pharmacovigilance activities in our regional territory and to reduce the burden of medication errors and inappropriate prescription.

Differences in safety and efficacy of oral anticoagulants in patients with non-valvular atrial fibrillation: A Bayesian analysis

BACKGROUND

Novel oral anticoagulants are the cornerstone of therapy for non-valvular atrial fibrillation patients to lower the risk of ischaemic stroke. Given the lack of head-to-head comparisons among oral anticoagulants, a Bayesian analysis was used to evaluate their safety and efficacy based on studies from real-world practice.

METHODS

The PubMed, Embase, Cochrane and Web of Science databases were searched for relevant studies. Bayesian analyses were conducted to estimate hazard ratios (HR) and 95% credible intervals (CrI) for the safety and efficacy of oral anticoagulants.

RESULTS

In the 22 studies included in our analysis, novel oral anticoagulants exhibited a clear advantage over warfarin in preventing ischaemic stroke, haemorrhagic stroke and, especially, intracranial haemorrhage. Incidence of major bleeding was lowest for apixaban, followed by dabigatran, warfarin and rivaroxaban. Gastrointestinal bleeding risk was lowest for apixaban, followed by warfarin, and was slightly lower for dabigatran than for rivaroxaban with no statistical difference (HR 1.05, 95% CrI 0.99-1.11). Ischaemic stroke risk was lowest for rivaroxaban, followed by apixaban, dabigatran and warfarin (HR 1.13, 95% CrI 1.07-1.20).

CONCLUSION

In real-world practice, apixaban may represent the optimal treatment in terms of safety and efficacy for patients with non-valvular atrial fibrillation. For patients with high risk of ischaemic events but low bleeding risk, rivaroxaban may be preferable.

XANAP: A real-world, prospective, observational study of patients treated with rivaroxaban for stroke prevention in atrial fibrillation in Asia

BACKGROUND

ROCKET AF and its East Asian subanalysis demonstrated that rivaroxaban was non-inferior to warfarin for stroke/systemic embolism (SE) prevention in patients with non-valvular atrial fibrillation (NVAF), with a favorable benefit-risk profile. XANAP investigated the safety and effectiveness of rivaroxaban in routine care in Asia-Pacific.

METHODS

XANAP was a prospective, real-world, observational study in patients with NVAF newly starting rivaroxaban. Patients were followed at ~3-month intervals for 1 year, or for ≥30 days after permanent discontinuation. Primary outcomes were major bleeding events, adverse events (AEs), serious AEs and all-cause mortality; secondary outcomes included stroke/SE. Major outcomes were adjudicated centrally.

RESULTS

XANAP enrolled 2273 patients from 10 countries: mean age was 70.5 years and 58.1% were male. 49.8% of patients received rivaroxaban 20 mg once daily (od), 43.8% 15 mg od and 5.9% 10 mg od. Mean treatment duration was 296 days, and 72.8% of patients had received prior anticoagulation therapy. Co-morbidities included heart failure (20.1%), hypertension (73.6%), diabetes mellitus (26.6%), prior stroke/non-central nervous system SE/transient ischemic attack (32.8%) and myocardial infarction (3.8%). Mean CHADS2, CHA2DS2-VASc and HAS-BLED scores were 2.3, 3.7 and 2.1, respectively. The rates (events/100 patient-years [95% confidence interval]) of treatment-emergent major bleeding, stroke and all-cause mortality were 1.5 (1.0-2.1), 1.7 (1.2-2.5) and 2.0 (1.4-2.7), respectively. Persistence was 66.2% at the study end.

CONCLUSIONS

The real-world XANAP study demonstrated low rates of stroke and bleeding in rivaroxaban-treated patients with NVAF from Asia-Pacific. The results were consistent with the real-world XANTUS study and ROCKET AF.

Novel oral anticoagulants and exodontia: the evidence

Background Haemostasis is crucial for the success of oral surgical treatment as bleeding problems can cause complications both pre- and post-operatively. Patients on anticoagulant drugs present a challenge due to their increased risk of bleeding.Aims To review the evidence for the management of oral surgery patients on novel oral anticoagulant therapy.Methods A literature review was conducted in May 2016 of free-text and MESH searches (keywords: apixaban, dabigatran, rivaroxaban and dental extractions) in the Cochrane Library, PubMed and CINAHL. Trial registers, professional bodies for guidelines and OpenGrey for unpublished literature were also searched. Studies were selected for appraisal after limits were applied (adult, human and English only studies) and inclusion/exclusion criteria imposed.Results Five studies were identified for critical appraisal using the CASP tools. These were a combination of systematic reviews and case series. Two case series were excluded due to low quality evidence. Curtin et al., Davis et al. and Constantinides et al. together with guidelines from the Scottish Dental Clinical Effectiveness Programme, have highlighted a protocol in managing these patients in a dental surgical setting.Conclusion Patients on novel anticoagulant therapy requiring dental surgery can be managed appropriately either without discontinuation of therapy or a delay in dose. For those patients at higher risks of postoperative bleeding complications, it is advised to liaise with the specialist physician.

Cost Effectiveness of Genotype-Guided Warfarin Dosing in Patients with Mechanical Heart Valve Replacement Under the Fee-for-Service System

BACKGROUND

Although studies assessing the cost effectiveness of genotype-guided warfarin dosing for the management of atrial fibrillation, deep vein thrombosis, and pulmonary embolism have been reported, no publications have addressed genotype-guided warfarin therapy in mechanical heart valve replacement (MHVR) patients or genotype-guided warfarin therapy under the fee-for-service (FFS) insurance system.

OBJECTIVE

The aim of this study was to evaluate the cost effectiveness of genotype-guided warfarin dosing in patients with MHVR under the FFS system from the Korea healthcare sector perspective.

METHODS

A decision-analytic Markov model was developed to evaluate the cost effectiveness of genotype-guided warfarin dosing compared with standard dosing. Estimates of clinical adverse event rates and health state utilities were derived from the published literature. The outcome measure was the incremental cost-effectiveness ratio (ICER) per quality-adjusted life-year (QALY). One-way and probabilistic sensitivity analyses were performed to explore the range of plausible results.

RESULTS

In a base-case analysis, genotype-guided warfarin dosing was associated with marginally higher QALYs than standard warfarin dosing (6.088 vs. 6.083, respectively), at a slightly higher cost (US$6.8) (year 2016 values). The ICER was US$1356.2 per QALY gained. In probabilistic sensitivity analysis, there was an 82.7% probability that genotype-guided dosing was dominant compared with standard dosing, and a 99.8% probability that it was cost effective at a willingness-to-pay threshold of US$50,000 per QALY gained.

CONCLUSION

Compared with only standard warfarin therapy, genotype-guided warfarin dosing was cost effective in MHVR patients under the FFS insurance system.

Antiplatelet Therapy Combinations and Thrombogenicity in Patients with Non-Valvular Atrial Fibrillation

BACKGROUND AND OBJECTIVES

Combination antiplatelet therapy reduces the risk of ischemic stroke compared with aspirin monotherapy in non-valvular atrial fibrillation (NVAF) patients. The underlying mechanism, however, remains unclear. In addition, the association between platelet inhibition and thrombogenicity in NVAF has not been evaluated.

SUBJECTS AND METHODS

We randomized 60 patients with NVAF that were taking 100 mg of aspirin daily (>1 month) to adding 75 mg of clopidogrel daily (CLPD group), 100 mg of cilostazol twice daily (CILO group), or 1000 mg of omega-3 polyunsaturated fatty acid twice daily (PUFA group). Biomarkers (von Willebrand factor antigen [vWF:Ag], fibrinogen, D-dimer, and high-sensitivity C-reactive protein [hs-CRP]) and platelet reactivity (PR), which were the levels stimulated by adenosine diphosphate (ADP), thrombin-receptor agonist peptide, collagen, and arachidonic acid, were measured at baseline and 30-day follow-up.

RESULTS

Combination antiplatelet therapy significantly reduced vWF:Ag and fibrinogen levels (7.7 IU/dL, p=0.015 and 15.7 mg/dL, p=0.005, respectively), but no changes were found in D-dimer and hs-CRP levels. The CLPD and CILO groups showed fibrinogen and vWF:Ag level reductions (24.9 mg/dL, p=0.015 and 9.3 IU/dL, p=0.044, respectively), whereas the PUFA group did not show any differences in biomarkers. Irrespective of regimen, the changes in fibrinogen and vWF:Ag levels were mainly associated with the change in ADP-mediated PR (r=0.339, p=0.008 and r=0.322, p=0.012, respectively).

CONCLUSION

In patients with NVAF, combination antiplatelet therapy showed reductions for vWF:Ag and fibrinogen levels, which may be associated with the inhibitory levels of ADP-mediated PR. The clinical implications of these findings need to be evaluated in future trials.

Use of dabigatran vs. warfarin with low-molecular-weight heparin bridging in catheter ablation for atrial fibrillation patients with a low CHADS2 score

The purpose of the present study was to compare the efficacy and safety of dabigatran and interrupted warfarin with low-molecular-weight heparin bridging in non-valvular atrial fibrillation (AF) catheter ablation. Previously, there has been concerns that bridging therapy increases bleeding events without the benefit of stroke prevention. It has been suggested that bridging therapy should be considered only for patients at high-risk of thrombosis. Nevertheless, bridging therapy in AF patients with a low CHADS2 score may be safe and effective. The authors performed a prospective, observational study that included consecutive 240 patients undergoing AF ablation in P.R. China. A total of 139 patients received 110 mg dabigatran twice daily and 101 patients took dose-adjusted warfarin that had been bridged with low-molecular-weight heparin. The mean patient age was 55.48 years with 72.1% being men and 74.2% having paroxysmal AF. One thromboembolic complication occurred in the dabigatran group compared to none in the warfarin group. Both the groups presented a similar major bleeding rate, total bleeding rate, and bleeding and thromboembolic complications. In patients undergoing AF ablation, the risk of bleeding or thromboembolic complications was similar for both dabigatran and interrupted warfarin with bridging therapy. Bridging therapy appeared to be safe and effective for the low-risk population.

Cost-Effectiveness of Apixaban versus Warfarin in Chinese Patients with Non-Valvular Atrial Fibrillation: A Real-Life and Modelling Analyses

Objectives

Many of the cost-effectiveness analyses of apixaban against warfarin focused on Western populations but Asian evidence remains less clear. The present study aims to evaluate the cost-effectiveness of apixaban against warfarin in Chinese patients with non-valvular atrial fibrillation (NVAF) from a public institutional perspective in Hong Kong.

Methods

We used a Markov model incorporating 12 health state transitions, and simulated the disease progression of NVAF in 1,000 hypothetical patients treated with apixaban/warfarin. Risks of clinical events were based on the ARISTOTLE trial and were adjusted with local International Normalized Ratio control, defined as the time in therapeutic range. Real-life input for the model, including patients’ demographics and clinical profiles, post-event treatment patterns, and healthcare costs, were determined by a retrospective cohort of 40,569 incident patients retrieved from a Hong Kong-wide electronic medical database. Main outcome measurements included numbers of thromboembolic and bleeding events, life years, quality-adjusted life years (QALYs) and direct healthcare cost. When comparing apixaban and warfarin, treatment with incremental cost-effectiveness ratio (ICER) less than one local GDP per capita (USD 33,534 in 2014) was defined to be cost-effective.

Results

In the lifetime simulation, fewer numbers of events were estimated for the apixaban group, resulting in reduced event-related direct medical costs. The estimated ICER of apixaban was USD 7,057 per QALY at base-case analysis and ranged from USD 1,061 to 14,867 per QALY under the 116 tested scenarios in deterministic sensitivity analysis. While in probabilistic sensitivity analysis, the probability of apixaban being the cost-effective alternative to warfarin was 96% and 98% at a willingness to pay threshold of USD 33,534 and 100,602 per QALY, respectively.

Conclusions

Apixaban is likely to be a cost-effective alternative to warfarin for stroke prophylaxis in Chinese patients with NVAF in Hong Kong.

Current Status and Time Trends of Oral Anticoagulation Use Among Chinese Patients With Nonvalvular Atrial Fibrillation: The Chinese Atrial Fibrillation Registry Study

BACKGROUND AND PURPOSE

Reported rates of oral anticoagulation (OAC) use have been low among Chinese patients with atrial fibrillation (AF). With improved awareness, changing guidelines, this situation may be changing over time. We aimed to explore the current status and time trends of OAC use in Beijing.

METHODS

We used the data set from the Chinese Atrial Fibrillation Registry (CAFR), a prospective, multicenter, hospital-based registry study involving 20 tertiary and 12 nontertiary hospitals in Beijing. A total of 11 496 patients with AF were enrolled from 2011 to 2014.

RESULTS

Seven thousand nine hundred seventy-seven eligible patients were included in this ancillary study. The proportions of OAC use were 36.5% (2268/6210), 28.5% (333/1168), and 21.4% (128/599) for patients with CHA2DS2-VASc scores ≥2, 1, and 0, respectively. Persistent AF, history of stroke/transient ischemic attack/peripheral embolism, diabetes mellitus, higher body mass index, and tertiary hospital management were factors positively associated with OAC use, whereas older age, previous bleeding, hypercholesterolemia, and established coronary artery disease were factors negatively associated with OAC use. Among patients with CHADS2 scores ≥2 and CHA2DS2-VASc scores ≥2, the proportion of OAC use increased from 31.3% to 64.5% and 30.2% to 57.7%, respectively, from 2011 to 2014. Variation in OAC use was substantial among different hospitals.

CONCLUSIONS

An improvement of OAC use among Chinese patients with AF in Beijing is observed in recent years although only 36.5% of patients with CHA2DS2-VASc score ≥2 received OAC. However, variations between different hospitals were large, suggesting that better education and awareness are needed to improve efforts for stroke prevention among AF patients.

CLINICAL TRIAL REGISTRATION

URL: http://www.chictr.org.cn/showproj.aspx?proj=5831. Unique identifier: ChiCTR-OCH-13003729.

Effect of suboptimal anticoagulation treatment with antiplatelet therapy and warfarin on clinical outcomes in patients with nonvalvular atrial fibrillation: A population-wide cohort study

BACKGROUND

The actual consequence of suboptimal anticoagulation management in patients with nonvalvular atrial fibrillation (NVAF) is unclear in the real-life practice.

OBJECTIVE

The purpose of this study was to identify the prevalence of suboptimally anticoagulated patients with NVAF and compare the effectiveness and safety of antiplatelet drugs with warfarin.

METHODS

We performed a retrospective cohort study using a population-wide database managed by the Hong Kong Hospital Authority. Patients newly diagnosed with NVAF during 2010-2013 were included in the analysis. A Cox proportional hazards regression model with 1:1 propensity score matching was used to compare the risk of ischemic stroke, intracranial hemorrhage, gastrointestinal bleeding, and all-cause mortality between patients receiving antiplatelet drugs and those receiving warfarin stratified by level of international normalized ratio (INR) control.

RESULTS

Of the 35,551 patients with NVAF, 30,294 (85.2%) had a CHA2DS2-VASc (congestive heart failure, hypertension, age ≥75 years [doubled], diabetes mellitus, age 65-74 years, prior stroke/transient ischemic attack [doubled], vascular disease, and sex category [female]) score of ≥2 (target group for anticoagulation). Of these, 7029 (23.2%) received oral anticoagulants and 18,508 (61.1%) received antiplatelet drugs alone. There were 1541 (67.7%) of warfarin users who had poor INR control (time in therapeutic range [2.0-3.0] <60%). Patients receiving warfarin had comparable risks of intracranial hemorrhage (hazard ratio [HR] 1.24; 95% confidence interval [CI] 0.65-2.34) and gastrointestinal bleeding (HR 1.23; 95% CI 0.84-1.81) and lower risk of ischemic stroke (HR 0.40; 95% CI 0.28-0.57) and all-cause mortality (HR 0.45; 95% CI 0.36-0.57) than did patients receiving antiplatelet drugs alone. Good INR control was associated with a reduced risk of ischemic stroke (HR 0.48; 95% CI 0.27-0.86) as compared with poor INR control. Modeling analyses suggested that ~40,000 stroke cases could be potentially prevented per year in the Chinese population if patients were optimally treated.

CONCLUSION

More than three-quarters of high-risk patients among this Chinese population with NVAF were not anticoagulated or had poor INR control. There is an urgent need to improve the optimization of anticoagulation for stroke prevention in patients with atrial fibrillation.

The Indian consensus guidance on stroke prevention in atrial fibrillation: An emphasis on practical use of nonvitamin K oral anticoagulants

The last ten years have seen rapid strides in the evolution of nonvitamin K oral anticoagulants (NOACs) for stroke prevention in patients with atrial fibrillation (AF). For the preparation of this consensus, a comprehensive literature search was performed and data on available trials, subpopulation analyses, and case reports were analyzed. This Indian consensus document intends to provide guidance on selecting the right NOAC for the right patients by formulating expert opinions based on the available trials and Asian/Indian subpopulation analyses of these trials. A section has been dedicated to the current evidence of NOACs in the Asian population. Practical suggestions have been formulated in the following clinical situations: (i) Dose recommendations of the NOACs in different clinical scenarios; (ii) NOACs in patients with rheumatic heart disease (RHD); (iii) Monitoring anticoagulant effect of the NOACs; (iv) Overdose of NOACs; (v) Antidotes to NOACs; (vi) Treatment of hypertrophic cardiomyopathy (HCM) with AF using NOACs; (vii) NOACs dose in elderly, (viii) Switching between NOACs and vitamin K antagonists (VKA); (ix) Cardioversion or ablation in NOAC-treated patients; (x) Planned/emergency surgical interventions in patients currently on NOACs; (xi) Management of bleeding complications of NOACs; (xii) Management of acute coronary syndrome (ACS) in AF with NOACs; (xiii) Management of acute ischemic stroke while on NOACs.

Choosing the right drug to fit the patient when selecting oral anticoagulation for stroke prevention in atrial fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia worldwide and is a growing health problem that is associated with a significantly increased risk of stroke and thromboembolism. Oral anticoagulant (OAC) therapy reduces the risk of stroke and all-cause mortality in patients with AF. OAC therapy is commonly given as a well-controlled vitamin K antagonist (VKA; e.g. warfarin) and can reduce the risk of stroke in AF patients by almost two-thirds. However, the widespread use of VKAs has been hampered by the unpredictable pharmacokinetic and pharmacodynamic properties of the drugs and justifiable concerns about the consequent risk of haemorrhage. The non-VKA OACs (NOACs) have revolutionized thromboprophylaxis in AF by providing therapeutic options with predictable pharmacodynamic and pharmacokinetic properties that are as efficacious as warfarin in the prevention of stroke and thromboembolism but are more convenient to use. In this review, we provide a patient-centred framework to assist clinicians in recommending the right OAC therapy to fit the individual patient with AF, including methods for stratifying the risk of stroke and haemorrhage and the chances of achieving tight control of VKA anticoagulation, and we discuss the properties of the NOACs that favour their use in particular patient cohorts.

Racial and Ethnic Disparities in Adverse Drug Events: A Systematic Review of the Literature

The 2014 National Action Plan for Adverse Drug Event Prevention has recognized adverse drug events (ADEs) as a national priority in order to facilitate a nationwide reduction in patient harms from these events. Throughout this effort, it will be integral to identify populations that may be at particular risk in order to improve care for these patients. We have undertaken a systematic review to evaluate the evidence regarding racial or ethnic disparities in ADEs with particular emphasis on anticoagulants, diabetes agents, and opioids due to the clinical significance and preventability of ADEs associated with these medication classes. From an initial search yielding 3302 studies, we identified 40 eligible studies. Twenty-seven of these included studies demonstrated the presence of a racial or ethnic disparity. There was no consistent evidence for racial or ethnic disparities in the eight studies of ADEs in general. Asians were most frequently determined to be at higher risk of anticoagulant-related ADEs, and black patients were most frequently determined to be at higher risk for diabetes agents-related ADEs. Whites were most frequently identified as at increased risk for opioid-related ADEs. However, few of these studies were specifically designed to evaluate racial or ethnic disparities, lacking a standardized approach to racial/ethnic categorization as well as control for potential confounders. We suggest the need for targeted interventions to reduce ADEs in populations that may be at increased risk, and we suggest strategies for future research.