Safety and effectiveness of apixaban in comparison to warfarin in patients with nonvalvular atrial fibrillation: a propensity-matched analysis from Japanese administrative claims data

Effectiveness and Safety of Apixaban in over 3.9 Million People with Atrial Fibrillation: A Systematic Review and Meta-Analysis

Background: There is a plethora of real-world data on the safety and effectiveness of direct-acting oral anticoagulants (DOACs); however, study heterogeneity has contributed to inconsistent findings. We compared the effectiveness and safety of apixaban with those of other direct-acting oral anticoagulants (DOACs) and vitamin K antagonists (VKA e.g., warfarin). Methods: A systematic review and meta-analysis was conducted retrieving data from PubMed, SCOPUS and Web of Science from January 2009 to December 2021. Studies that evaluated apixaban (intervention) prescribed for adults (aged 18 years or older) with AF for stroke prevention compared to other DOACs or VKAs were identified. Primary outcomes included stroke/systemic embolism (SE), all-cause mortality, and major bleeding. Secondary outcomes were intracranial haemorrhage (ICH) and ischaemic stroke. Randomised controlled trials and non-randomised trials were considered for inclusion. Results: In total, 67 studies were included, and 38 studies were meta-analysed. Participants taking apixaban had significantly lower stroke/SE compared to patients taking VKAs (relative risk (RR) 0.77, 95% confidence interval (CI) 0.64–0.93, I² = 94%) and dabigatran (RR 0.84, 95% CI 0.74–0.95, I² = 66%), but not to patients administered rivaroxaban. There was no statistical difference in mortality between apixaban and VKAs or apixaban and dabigatran. Compared to patients administered rivaroxaban, participants taking apixaban had lower mortality rates (RR 0.83, 95% CI 0.71–0.96, I² = 96%). Apixaban was associated with a significantly lower risk of major bleeding compared to VKAs (RR 0.58, 95% CI 0.52–0.65, I² = 90%), dabigatran (RR 0.79, 95% CI 0.70–0.88, I² = 78%) and rivaroxaban (RR 0.61, 95% CI 0.53–0.70, I² = 87%). Conclusions: Apixaban was associated with a better overall safety and effectiveness profile compared to VKAs and other DOACs.

Association of Direct Oral Anticoagulants (DOACs) and Warfarin With Haemorrhagic Risk by Applying Correspondence Analysis to Data From the Italian Pharmacovigilance Database - A Case Study

Introduction: Post-marketing data on the risks associated with direct oral anticoagulants (DOACs) are conflicting and only few studies evaluated a comparison between each different DOAC. Real-world data from pharmacovigilance databases can help to better define the safety profile of each DOAC and warfarin. However, Correspondence Analysis (CA) could represent a useful tool in this context. Objective: In the attempt to assess the usefulness of CA as a signal detection pharmacovigilance tool, we applied this method to the Italian Pharmacovigilance Database (RNF, Rete Nazionale di Farmacovigilanza), by comparing with disproportionality analysis on warfarin and DOACs. Methods: Study based on AEs sent to RNF by Campania Region from 2008 to 2021, in which warfarin, dabigatran, apixaban, edoxaban or rivaroxaban were reported as suspected drug. AEs were clustered into three Standardized MedDRA Queries (SMQs): Central Nervous System Haemorrhages and Conditions (CNSH), GastroIntestinal Perforation, Ulceration, Obstruction or Haemorrhages (GIPUOH) and other Haemorrhages (HH). Non-haemorrhagic AEs were included in a fourth cluster (nHH). Results: We retrieved 1,161 reports: 41.5% are associated to warfarin, 21.0% to dabigatran, 17.8% to rivaroxaban, 13.9% to apixaban and 5.8% to edoxaban. No significant differences in age distribution were observed. Results of CA showed that dabigatran and warfarin have the highest contribution (44.910 and 47.656, respectively) to the inertia of Dimension 1 as well as apixaban and dabigatran to the inertia of Dimension 2 (53.768 and 30.488, respectively). Edoxaban and rivaroxaban showed a negligible total contribution. CA biplot showed positive associations between warfarin and HH, apixaban and CNSH and dabigatran and nHH. Conclusion: Results seem to confirm that DOACs are not interchangeable. Apixaban was surprisingly associated with a higher risk of cerebral haemorrhage. As expected, our data support the better safety profile of DOACs than warfarin in terms of skin and respiratory tract hemorrhagic risks. Finally, we showed how CA could play a complementary role in analyzing data from pharmacovigilance databases.

Comparative Safety and Effectiveness of Apixaban vs. Warfarin in Oral Anticoagulant-Naïve Japanese Patients With Non-Valvular Atrial Fibrillation - A Retrospective Chart Review Study

BACKGROUND

The risk of bleeding and stroke/systemic embolism (SE) events associated with apixaban vs. warfarin among oral anticoagulant-naïve Japanese patients with non-valvular atrial fibrillation (NVAF) has not been well studied in daily clinical practice.Methods and Results:Clinical data for 12,090 patients were retrospectively extracted from the medical records of patients with NVAF (aged ≥20 years, creatinine clearance [CrCl] ≥15 mL/min) newly initiated to apixaban or warfarin treatment between January 1, 2010, and December 31, 2017, at 315 general practitioner clinics and 87 hospitals across Japan. After applying propensity score matching, patient characteristics were well-balanced between the apixaban and warfarin groups (4,523 patients each). The incidence rate (per 100 person-years) of major bleeding was lower in the apixaban vs. warfarin group (1.17 vs. 1.64; hazard ratio [HR], 0.71; 95% confidence interval [CI], 0.54-0.93; P=0.01), as was that of stroke/SE (1.14 vs. 1.73; HR, 0.65; 95% CI, 0.50-0.85; P<0.01). When patients were stratified by CrCl (≥50 mL/min and <50 mL/min), the P value for interaction was not statistically significant between subgroups (P=0.31 for major bleeding and P=0.32 for stroke/SE).

CONCLUSIONS

The benefit of apixaban over warfarin for the reduction in risk of major bleeding and stroke/SE could be generalizable to daily clinical practice and to patients with reduced renal function.

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.

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.

Validity of Claims Diagnosis Codes for Cardiovascular Diseases in Diabetes Patients in Japanese Administrative Database

Background

Observational studies using large claims databases for diabetes patients have been increasingly conducted. While validation of outcomes is important in such studies, validation studies from Japan are still scarce and small in scale with questions remaining on the representativeness of their findings. We examined the positive predictive value (PPV) of outcomes that often develop in type 2 diabetes patients: cardiovascular outcomes including congestive heart failure (CHF), myocardial infarction (MI), stroke-related diseases, and renal outcomes including end stage renal disease (ESRD), and death using a large Japanese database containing administrative claims and electronic medical record (EMR) data.

Patients and Methods

We used patient-level administrative claims data from 2003 and EMR data from 1985 to the most recent data up to December 2018 provided by Real World Data Co., Ltd. The database consisted of data from over 200 hospitals including ≥12 million uniquely identifiable patients. Among patients who had ≥1 type 2 diabetes diagnosis in the EMR, those who had administrative claims for each outcome were identified, and then the PPV was calculated for each outcome using the EMR as the gold standard.

Results

The numbers of patients identified for each outcome were 1,700 for MI, 2,027 for hemorrhagic stroke, 3,722 for ESRD, 4,723 for ischemic stroke, 5,404 for CHF, 6,678 for any type of stroke, and 10,815 for death. PPVs ranged from 67.4% for ESRD, 78.7% for MI, 80.3% for death, 85.7% for ischemic stroke, 88.9% for any type of stroke, 89.9% for hemorrhagic stroke, and 95.7% for CHF. A post hoc analysis showed PPV for ESRD as 83.8%.

Conclusion

This large-scale validation study on diagnosis in administrative claims showed reasonable PPVs for the outcomes. We believe that the definitions of outcomes can be considered to be appropriate for future studies using Japanese administrative claims data.

Safety and effectiveness of non-vitamin K oral anticoagulants versus warfarin in real-world patients with non-valvular atrial fibrillation: a retrospective analysis of contemporary Japanese administrative claims data

Objective

To assess the safety (ie, risk of bleeding) and effectiveness (ie, risk of stroke/systemic embolism (SE)) separately for four non-vitamin K oral anticoagulants (NOACs; apixaban, dabigatran, edoxaban and rivaroxaban) versus warfarin in Japanese patients with non-valvular atrial fibrillation (NVAF), including those at high risk of bleeding and treated with reduced doses of NOACs.

Methods

We conducted a retrospective analysis of electronic health records and claims data from 372 acute care hospitals in Japan for patients with NVAF newly initiated on NOACs or warfarin. Baseline characteristics were balanced using inverse probability of treatment weighting with stabilised weights (s-IPTW). Bleeding risk and stroke/SE risk were expressed as HRs with 95% CIs. Two sensitivity analyses were conducted.

Results

A total of 73 989 patients were eligible for analysis. Notably, 52.8%-81.9% of patients received reduced doses of NOACs. After applying s-IPTW, patient characteristics were well balanced across warfarin/NOAC cohorts. The mean within-cohort age, CHADS₂ score and CHA₂DS₂-VASc score were 76 years, 2.2-2.3 and 3.8, respectively. In all age categories, the majority of the HRs for major bleeding, any bleeding and stroke/SE were equal to or below 1 for all NOACs versus warfarin. Apixaban was the only NOAC associated with a significantly lower risk of any bleeding. There was a trend towards increased risk reduction with NOACs versus warfarin in patients with body weight ≥60 kg. In patients with renal disease, the HRs for apixaban versus warfarin were below 1 for major bleeding, any bleeding and stroke/SE, with statistical significance observed for the risk reduction in stroke/SE versus warfarin. In the sensitivity analysis, there were no large differences in HRs between the two observational periods.

Conclusions

In patients with NVAF primarily treated with reduced-dose NOACs, the risks of stroke/SE and major bleeding were significantly lower with NOACs versus warfarin.

Coagulopathy reversal in intracerebral haemorrhage

As intracerebral hemorrahge becomes more frequent as a result of an aging population with greater comorbidities, rapid identification and reversal of precipitators becomes increasingly paramount. The aformentioned population will ever more likely be on some form of anticoagulant therapy. Understanding the mechanisms of these agents and means by which to reverse them early on is critical in managing the acute intracerebral hemorrhage.

Potential of machine learning methods to identify patients with nonvalvular atrial fibrillation

Aim: Nonvalvular atrial fibrillation (NVAF) is associated with an increased risk of stroke however many patients are diagnosed after onset. This study assessed the potential of machine-learning algorithms to detect NVAF. Materials & methods: A retrospective database study using a Japanese claims database. Patients with and without NVAF were selected. 41 variables were included in different classification algorithms. Results: Machine learning algorithms identified NVAF with an area under the curve of >0.86; corresponding sensitivity/specificity was also high. The stacking model which combined multiple algorithms outperformed single-model approaches (area under the curve ≥0.90, sensitivity/specificity ≥0.80/0.82), although differences were small. Conclusion: Machine-learning based algorithms can detect atrial fibrillation with accuracy. Although additional validation is needed, this methodology could encourage a new approach to detect NVAF.

Patient characteristics and stroke and bleeding events in nonvalvular atrial fibrillation patients treated with apixaban and vitamin K antagonists: a Spanish real-world study

Aim: To compare the risk of stroke, systemic thromboembolism and bleeding, in patients initiating apixaban or acenocoumarol for the treatment of nonvalvular atrial fibrillation. Methods: An observational, retrospective study was performed using medical records of patients who initiated apixaban or acenocoumarol between 2015 and 2017. Propensity score matching was used to match patients; stroke, systemic thromboembolism, major and minor bleeding events were compared between the matched patients. Results: Patients who were prescribed apixaban had a lower rate of systemic embolism/stroke (hazard ratio [HR] = 0.54; 95% CI: 0.38–0.78; p = 0.001), minor bleeding (HR = 0.64; 95% CI: 0.52–0.79; p < 0.001) and major bleeding (HR = 0.51; 95% CI: 0.37–0.72; p < 0.001). Conclusion: Patients prescribed apixaban for the treatment of nonvalvular atrial fibrillation had lower rates of thromboembolic events and minor/major bleeding than patients on acenocoumarol.

Warfarin vs. apixaban in nonvalvular atrial fibrillation, and analysis by concomitant antiarrhythmic medication use: A national retrospective study

BACKGROUND

No real-world data exist on outcomes in patients on anticoagulants and concomitant antiarrhythmic medications. This study aims to compare the safety and effectiveness of apixaban and warfarin, first in patients with nonvalvular atrial fibrillation (NVAF) and then in patients on concurrent antiarrhythmic medications.

METHODS

A retrospective cohort study was conducted using a large US electronic medical record database (2012-2016). Patients with NVAF on warfarin or apixaban were included. The primary endpoint was a composite of stroke (ischemic or hemorrhagic) or systemic embolism. The primary safety endpoint was major bleeding (ISTH definition). Patients were matched using propensity scoring. Univariate survival analyses were conducted by using the log-rank test and Kaplan-Meier survival curves. A subgroup analysis was conducted to assess outcomes on patients on concurrent antiarrhythmic medications.

RESULTS

A total of 332 100 patients with NVAF were identified, and 20 378 were included in the propensity-matching analysis. No baseline differences were seen in age, comorbidities, or CHA 2 DS 2-VASc score. The primary endpoint occurred in 122 (1.2%) patients on apixaban compared to 166 (1.63%) on warfarin (hazard ratio, 0.84; 95% confidence interval [CI], 0.79-0.88). Major bleeding occurred at a lower rate in the apixaban group (n = 600, 5.89%) compared to warfarin (n = 887, 8.71%) (odds ratio, 0.65; 95% CI, 0.58-0.73). In patients on concurrent antiarrhythmic medications (n = 2498), there was no difference in thrombotic (1.04% vs. 1.37%; P = 0.42) or bleeding events (5.29% vs. 6.89%; P = 0.08).

CONCLUSION

Apixaban was associated with reduced stroke/systemic embolism and bleeding when compared with warfarin. No difference was seen in thrombotic or bleeding events in patients on concurrent antiarrhythmic medications.

Safety and effectiveness of apixaban in Japanese patients with nonvalvular atrial fibrillation in clinical practice: A regulatory postmarketing surveillance, the STANDARD study

BACKGROUND

Apixaban, a non-vitamin K oral anticoagulant (NOAC), was approved in Japan in 2012 for the prevention of thromboembolic events in patients with nonvalvular atrial fibrillation (NVAF). However, the safety and effectiveness of apixaban in clinical practice have not yet been elucidated thoroughly among Japanese NVAF patients.

METHODS

A postmarketing surveillance study was conducted to determine the safety and effectiveness of apixaban. Patients were followed-up for 104 weeks. Outcome events included adverse drug reactions (ADRs), hemorrhages, and thromboembolic events (ischemic stroke, systemic embolism [SE], and transient ischemic attack [TIA]).

RESULTS

Among 6306 NVAF patients in the safety analysis set (age, 74.5 ± 10.1 years; women, 41.1%; and CHADS 2 score, 2.0 ± 1.4), 3600 patients (57.1%) received the standard dose (5 mg twice daily) and 2694 (42.7%) received a reduced dose (2.5 mg twice daily) of apixaban. ADRs occurred in 604 patients (9.58%), with the most common being epistaxis (0.86%), subcutaneous hemorrhage (0.67%), and hematuria (0.57%). Incidence rate of any hemorrhages and major hemorrhage was 5.52% per year and 2.36% per year, respectively. Incidence rate of ischemic stroke/SE/TIA was 1.00% per year among 6286 patients in the effectiveness analysis set. Among three subgroups (3106 apixaban initiators, 2038 patients switched from warfarin, and 1118 patients switched from other NOACs), incidence rates of major hemorrhage (P = 0.221 for trend) and ischemic stroke/SE/TIA (P = 0.686 for trend) were comparable.

CONCLUSIONS

No new safety signals of apixaban were identified in Japanese NVAF patients. Safety and effectiveness of apixaban were consistent with those in the ARISTOTLE study.

Stroke Prevention in Atrial Fibrillation: Focus on Asian Patients

Atrial fibrillation (AF) is the most common arrhythmia conferring a fivefold increased risk of stroke. Stroke prevention is the cornerstone of management of patients with AF. Asians have a generally higher incidence of AF-related risks of stroke and bleeding (particularly intracranial bleeding), compared with non-Asians. Despite the well-documented efficacy and relative safety of oral anticoagulation for stroke prevention among Asians, the suboptimal use of oral anticoagulation remains common. The current narrative review aims to provide a summary of the available evidence on stroke prevention among patients with AF focused on the Asia region, regarding stroke and bleeding risk evaluation, the performance of oral anticoagulation, and current use of thromboprophylaxis.