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

Appropriateness of direct oral anticoagulant dosing in patients with atrial fibrillation at a tertiary care hospital in Thailand

Background

Appropriate dosing of direct oral anticoagulants (DOACs) has been associated with clinical efficacy and safety. Several studies have shown that DOAC dosing are often inconsistent with guideline recommendations. Little is known about this issue in Thailand. This study aimed to evaluate the appropriateness of DOAC dosing in Thai hospitalized patients with atrial fibrillation (AF).

Method

This was a retrospective descriptive study conducted on hospitalized patients at Rajavithi Hospital, a tertiary care hospital in Thailand. Inpatients diagnosed with AF and treated with DOACs between February 2021 and February 2023 were enrolled in the study. The appropriate dosing of DOACs was assessed according to the recommendation of the 2021 European Heart Rhythm Association Practical Guide on the Use of Non-Vitamin K Antagonist Oral Anticoagulants in Patients with Atrial Fibrillation (EHRA). Descriptive statistics were used to analyze the data; median (interquartile range) for continuous variables, and numbers and percentages for categorical variables.

Results

A total of 120 patients with AF were evaluated for dosing. The patients received rivaroxaban in 47 cases (39.2 %), apixaban in 32 cases (26.7 %), edoxaban in 31 cases (25.8 %), and dabigatran in 10 cases (8.3 %). Most of the patients were elderly, with a median age of 77.5 (68-84) years. Females were predominant (57.5 %). Our findings indicate that the prevalence of appropriate dosing of DOACs was 63.3 %. However, approximately one-third of patients received inappropriate dosing, with 24 (20.0 %) being overdosed, and 20 (16.7 %) being underdosed. The highest overdosing and underdosing rates were seen in dabigatran (90.0 %) and apixaban (21.9 %), respectively.

Conclusion

Inappropriate dosing of DOACs according to the 2021 EHRA recommendations was high in 36.7 %, with overdosing mostly occurring in 20.0 %. The high number of inappropriate dosing highlights the need for implementation of optimal strategies to select the appropriate dose of DOACs in Thai hospitalized patients with AF.

A comparative study of the clinical benefits of rivaroxaban and dabigatran in patients with nonvalvular atrial fibrillation with high bleeding risk

Objective

Rivaroxaban and dabigatran are approved to reduce the risk of stroke in patients with nonvalvular atrial fibrillation (NVAF). However, the clinical benefits of rivaroxaban and dabigatran in people with high bleeding risk are unclear.

Methods

A retrospective study was conducted on NVAF patients admitted to the First Affiliated Hospital of Zhengzhou University from May 31, 2016 to May 31, 2019. These patients had a high risk of bleeding and were taking at least one study medication. The aim of the study was to evaluate clinical benefits by comparing the efficacy and safety risks of these two medications.

Results

A total of 1,301 patients with high bleeding risk were enrolled, including 787 patients in the rivaroxaban group and 514 patients in the dabigatran group. Results of the primary efficacy benefit endpoint were obtained from 104 patients (13.21%) in the rivaroxaban group and 81 (15.76%) patients in the dabigatran group [hazard ratio (HR): 0.860; 95% confidence interval (CI): 0.637-1.162; P = 0.327], this indicates that there was no significant difference between dabigatran and rivaroxaban in preventing stroke and systemic embolism in patients with high bleeding risk NVAF. The principal safety end points were observed in 49 (6.23%) patients in the rivaroxaban group and in 36 (7.00%) patients in the dabigatran group (HR: 0.801 in the rivaroxaban group; 95% CI: 0.512-1.255; P = 0.333), this indicates that there was no a significant difference in reducing fatal bleeding and critical organ bleeding. With respect to secondary efficacy and benefit endpoints, 28 (3.56%) patients in the rivaroxaban group and 26 (5.06%) patients in the dabigatran group died, with an HR of 0.725 (95% CI: 0.425-1.238; P = 0.239); 32 (4.07%) patients in the rivaroxaban group; and 31 (6.03%) patients in the dabigatran group had myocardial infarction (MI), with an HR of 0.668 (95% CI: 0.405-1.102, P = 0.114) in the rivaroxaban group, this indicates that there was no significant difference between dabigatran and rivaroxaban in preventing all-cause death and MI.

Conclusions

In NVAF patients with high bleeding risk, there was no significant difference between dabigatran and rivaroxaban in preventing stroke and systemic embolism. There was also no significant difference between dabigatran and rivaroxaban in reducing fatal and critical organ bleeding.

Clinical Trial Registration

Chinese Clinical Trials Registry, identifier ChiCTR2100052454.

Comparative safety and effectiveness of non-vitamin K oral anticoagulants versus warfarin in patients with non-valvular atrial fibrillation: A network meta-analysis

BACKGROUND

The introduction of non-vitamin K antagonist oral anticoagulants (NOACs), with a non-inferior or superior clinical efficacy profile compared to vitamin K antagonists (VKAs), has significantly improved the safety profile and treatment adherence of patients with non-valvular atrial fibrillation (AF). However, few studies have compared the effectiveness and safety of NOACs. Therefore, we conducted this systematic review and network meta-analysis to compare the safety and clinical effectiveness of NOACs and VKAs in patients with non-valvular AF.

METHODS

An online bibliographic search was conducted to retrieve real-world evidence studies published between January 2019 and June 2022.

RESULTS

Dabigatran was associated with lower risks of major bleeding, ischemic stroke, and intracranial hemorrhage than warfarin. Among the NOACs, only dabigatran had a lower risk of all-cause mortality than warfarin. Dabigatran was also associated with lower risks of major bleeding and intracranial hemorrhage than rivaroxaban.

CONCLUSION

Our meta-analysis confirms that dabigatran's real-world safety and clinical effectiveness align with the results of pivotal clinical trials.

Factor Xa inhibitors versus warfarin in patients with non-valvular atrial fibrillation and diabetes mellitus: a systematic review and meta-analysis of randomized controlled trials

Background

Patients with non-valvular atrial fibrillation with diabetes face increased stroke and cardiovascular risks. This study compares factor Xa inhibitors and warfarin using data from randomized controlled trials (RCTs).

Methods

MEDLINE, Embase, and Cochrane CENTRAL databases were searched for RCTs comparing the risk of efficacy and safety of any factor Xa inhibitors with dose-adjusted warfarin by diabetes status. Incidence of stroke/systemic embolism, major bleeding, intracranial hemorrhage, ischemic stroke, all-cause mortality, risk of hemorrhagic stroke, and myocardial infarction were among the outcomes of interest. A generic inverse-weighted random-effects model was used to calculate hazard ratios (HRs) with 95 percent confidence intervals (CIs).

Results

After applying exclusion criteria, four RCTs containing 19 818 patients were included in the analysis. Compared with warfarin, meta-analysis showed statistically significant reduction in incidence of stroke/systemic embolism (HR 0.80 [95% CI 0.69-0.92]; P=0.002), intracranial hemorrhage (HR 0.49 [95% CI 0.37-0.65]; P<0.001), and risk of hemorrhagic stroke (HR 0.37 [95% CI 0.20-0.66]; P=0.001) in patients on factor Xa inhibitors. However, there was no discernible difference between two treatment arms in incidence of major bleeding (HR 0.93 [95% CI 0.84-1.04]; P=0.19), ischemic stroke (risk ratio (RR) 0.90 [95% CI 0.73-1.12; P=0.34), myocardial infarction (RR 0.88 [95% CI 0.67-1.15]; P=0.35), and all-cause mortality (RR 0.89 [95% CI 0.79-1.01]; P=0.06).

Conclusion

Factor Xa inhibitors show a favorable balance between efficacy and safety compared with warfarin, which is consistent across a wide range of patients with atrial fibrillation known to be at high risk for both ischemic and bleeding events.

A Systematic Review of the Efficacy and Safety of Tenecteplase Versus Streptokinase in the Management of Myocardial Infarction in Developing Countries

Myocardial infarction (MI) is a significant cause of morbidity and mortality in low- and middle-income countries. Fibrinolytic agents and percutaneous coronary intervention (PCI) are the main approaches for the recanalization and reperfusion of the myocardium following MI. Many studies have shown that PCI is superior to thrombolytics due to better outcomes and decreased mortality. Nevertheless, PCI's mortality gain over thrombolysis decreases as the time between presentation and PCI procedure increases. Furthermore, PCI is not widely available in most developing countries; thus, it cannot be delivered promptly. Most patients in developing countries cannot afford the cost of PCI. Thus, thrombolytic therapy remains essential to managing MI in developing countries and should not be disregarded. Tenecteplase (TNK) and streptokinase (SK) are the two most widely used fibrinolytics in managing MI in underdeveloped nations. Despite their widespread availability, comparative studies on them have been inconclusive. This study aims to review the available literature on the effectiveness and safety of TNK versus SK in managing MI in resource-poor nations. The study is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) extension and analyzed according to Cochrane guidelines on synthesis without meta-analysis. A comprehensive literature search for studies comparing TNK and STK was conducted on EMBASE, Cochrane Library, Web of Science, CINAHL, Scopus, Google Scholar, and Ovid version of MEDLINE databases. A reference list of the eligible articles and systematic reviews was also screened. A narrative synthesis of the available data was done by representing the data on the effect direction plot, followed by vote counting. Of the 2284 references retrieved from the databases, only 17 studies met the inclusion criteria and were selected for final analysis. The study suggested that TNK is more effective in complete ST-segment resolution (80% vs 10% on the effect direction plot) and symptom relief (80% vs 20%) than SK. SK and TNK were comparable in achieving successful fibrinolysis (50% vs 50%). For the safety parameters, TNK is associated with a lesser risk of major bleeding than SK (88.9% vs 11.1%) and minor bleeding (25% vs 75%). SK was linked with a higher risk of hypotension/shock (77.8% vs 11.1%) and anaphylaxis/allergy (100% vs 0%). Long-term mortality was higher in the SK arm (100% vs 0%). In-hospital mortality is comparable between the two agents (37.5% vs 37.5%). There is conflicting evidence regarding other safety and efficacy endpoints. Compared to SK, TNK results in better complete ST-segment resolution and symptom relief. A higher risk of long-term mortality, increased risk of major and minor bleeding, hypotension, and allergy/anaphylaxis was observed in patients who received SK. Both agents were comparable in terms of in-hospital mortality and successful fibrinolysis. Controversy exists regarding which agent is linked with increased risk of 30-35-day mortality benefit and stroke. Randomized controlled trials (RCTs) with large sample sizes are needed to establish TNK vs SK superiority in efficacy and safety. The long-term duration of follow-up of the mortality rate of the two agents is also essential, as most patients in these regions cannot afford the recommended PCI post-fibrinolysis.

Integrating Real-World Evidence in Economic Evaluation of Oral Anticoagulants for Stroke Prevention in Non-valvular Atrial Fibrillation in a Developing Country

OBJECTIVE

This study aimed to estimate the cost effectiveness of non-vitamin K oral anticoagulants (NOACs) compared with warfarin for stroke prevention in patients with non-valvular atrial fibrillation (NVAF) in Thailand where suboptimal anticoagulation control is common.

MATERIALS AND METHODS

A hypothetical cohort of 65-year-old patients with NVAF and their disease progression was simulated in the Markov model. The following anticoagulant agents were used: warfarin, dabigatran, rivaroxaban, and apixaban. Warfarin with high, intermediate, and low time in therapeutic ranges (TTR) was used as the three different reference treatments. Baseline clinical events were obtained from a recently published real-world study in Thailand. A lifetime horizon was utilized in this model, and all analyses were performed from societal and healthcare perspectives. The results were reported as incremental cost-effectiveness ratios (ICERs) in 2021 US dollars per quality-adjusted life-year (QALY) gained. The sensitivity analyses were performed to assess the influence of parameter uncertainty.

RESULTS

Apixaban was a cost-effective intervention compared with warfarin with low and intermediate TTR groups. In the low TTR group, the ICERs were $779 and $816 per QALY gained from the societal and healthcare perspectives, respectively, and in the intermediate TTR group, the ICERs were $2038 and $3159 per QALY gained from the societal and healthcare perspectives, respectively. Both ICERs were below the accepted willingness-to-pay threshold ($4806) in the context of Thailand's healthcare.

CONCLUSIONS

In a developing country where suboptimal anticoagulation control is common, apixaban was the cost-effective alternative to warfarin for patients with both low and intermediate TTR control.

Economic Evaluation of Direct Oral Anticoagulants Compared to Warfarin for Venous Thromboembolism in Thailand: A Cost-Utility Analysis

BACKGROUND

Direct oral anticoagulants (DOACs) have been used for venous thromboembolism (VTE) in Thailand. However, they have not been listed in the National List of Essential Medicines (NLEM). A cost-effectiveness analysis is needed to aid policymakers in deciding whether DOACs should be listed in the NLEM. This study aimed to assess the cost-effectiveness of DOACs for patients with VTE in Thailand.

METHODS

A cohort-based state transition model was constructed from a societal perspective with a lifetime horizon. All available DOACs, including apixaban, rivaroxaban, edoxaban, and dabigatran, were compared with warfarin. A 6-month cycle length was used to capture all costs and health outcomes. The model consisted of nine health states, including VTE on treatment, VTE off treatment, recurrent VTE, clinically relevant non-major bleeding, gastrointestinal bleeding, intracranial bleeding, post-intracranial bleeding, chronic thromboembolic pulmonary hypertension, and death. All inputs were based on a comprehensive literature review. The model outcomes included total cost and quality-adjusted life-years (QALYs) with a 3% annual discount rate. A fully incremental cost-effectiveness analysis and the incremental cost-effectiveness ratio (ICER) per QALY gained were calculated at a willingness-to-pay (WTP) of THB 160,000/QALY ($5003). The robustness of the findings was assessed using deterministic and probabilistic sensitivity analyses.

RESULTS

All DOACs were associated with a decreased risk of VTE recurrence and intracranial hemorrhage. In the base-case analysis, apixaban could increase 0.16 QALYs compared with warfarin. An ICER for apixaban was 269,809 Thai baht (THB)/QALY ($8437/QALY). Rivaroxaban had a better QALY than warfarin at 0.09 QALYs with an ICER of 757,363 THB/QALY ($23,682/QALY). Edoxaban and dabigatran could also increase by 0.10 QALYs with an ICER of 709,945 THB ($22,200) and 707,145 THB ($22,122)/QALY, respectively. Our probabilistic sensitivity analyses indicated that warfarin had a 99.8% possibility of being cost-effective, while apixaban had a 0.2% possibility of being cost-effective at the current WTP. Other DOACs had no possibility of being cost-effective.

CONCLUSIONS

All DOACs were not cost-effective for VTE treatment at the current WTP in Thailand. Apixaban is likely to be the best option among DOACs.

Effectiveness and Safety of Direct Oral Anticoagulants in Thai Patients with Atrial Fibrillation: A Real-World Retrospective Cohort Study

Background

Direct oral anticoagulants (DOACs) are commonly used to prevent stroke and systemic embolism in patients with atrial fibrillation (AF). However, studies into their effectiveness and safety in the Thai population have so far been limited.

Objectives

To study the effectiveness and safety of warfarin and DOACs among Thai AF patients

Methods

A retrospective cohort study was conducted on AF patients at Ramathibodi Hospital from 2013 to 2018. All patients were followed for at least 1 year. Relevant clinical information was collected and compared between AF patient groups receiving warfarin, dabigatran, rivaroxaban, and apixaban. The primary outcome was a composite of major bleeding, ischemic stroke, and systemic thromboembolism. The secondary outcomes were all-cause mortality and disease-specific mortality caused by major bleeding, ischemic stroke, and systemic thromboembolism.

Results

A total of 1680 AF patients were enrolled in the study (warfarin 1193, apixaban 140, dabigatran 193, rivaroxaban 114). The estimated incidence of composite outcome was 16% [95% CI, 14−18%] and 12.4% [95% CI, 9.4−15.3%] in the warfarin and DOAC group, respectively, given a number needed to treat of 28 [95% CI, 3−52]. Compared with warfarin, DOACs were associated with both lower rate of all-cause mortality (4.9% [22/447] vs 8% [98/1193]) and lower disease-specific mortality (0.4% [2/447] and 1% [12/1193]).

Conclusions

This study suggests DOACs were associated with a lower risk of major bleeding, ischemic stroke, and systemic thromboembolism compared to warfarin in Thai patients with AF. Patients receiving DOAC also had a lower rate of all-cause mortality and disease-specific mortality.

Using real world evidence to generate cost-effectiveness analysis of fibrinolytic therapy in patients with ST-segment elevation myocardial infarction in Thailand

BACKGROUND

Due to limited access to primary percutaneous coronary intervention for the management of ST-segment elevation myocardial infarction (STEMI) in low-to-middle-income countries (LMICs), fibrinolysis serves as a vital alternative reperfusion therapy. Among fibrinolytic agents, the cost-effectiveness of tenecteplase (TNK) in LMICs as compared to streptokinase (SK) for STEMI management remains unknown.

METHODS

Cost-effectiveness was analyzed using a hybrid model consisting of short-term analysis (30-days decision tree model) and long-term analysis (Markov model). Both health care provider and societal perspectives over a lifetime horizon with 3% discount rate were considered. Input parameters were obtained from Thailand's national health database, a network meta-analysis and literature review. Outcome measure was an incremental cost-effectiveness ratio (ICER) determined by an incremental cost per quality-adjusted life years (QALY) gain. An ICER of less than $5,590 per QALY gain is considered cost-effective. Series of sensitivity analyses were also performed.

FINDINGS

From the societal perspective, TNK increases cost by $827 and increases QALY by 0·173. Thus, the ICER is $4,777 per QALY gained. Similarly, the ICER from health care provider perspective is $4,664 per QALY gained. In the probabilistic sensitivity analysis, using 5,590 USD per QALY as threshold, the probability of TNK being cost-effective was 83% from both perspectives. The most influential parameters were risk ratio of death for treatment with TNK compared to SK and drug cost of TNK.

INTERPRETATION

In a resource-limited country like Thailand, tenecteplase is a cost-effective fibrinolytic drug for treatment of STEMI compared to streptokinase.

FUNDING

None.

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.

Antithrombotic therapy and clinical outcomes at 1 year in the Spanish cohort of the EORP-AF Long-term General Registry

BACKGROUND

Atrial fibrillation (AF) increases the risk of thromboembolism. We investigate the efficacy and safety of oral anticoagulation (OAC) therapy and explored the number needed to treat for net effect (NNTnet) of OAC in the Spanish cohort of the EURObservational Research Programme-AF (EORP-AF) Long-term General Registry.

METHODS

The EORP-AF General Registry is a prospective, multicentre registry conducted in ESC countries, including consecutive AF patients. For the present analysis, we used the Spanish cohort, and the primary outcome was any thromboembolism (TE)/acute coronary syndrome (ACS)/cardiovascular death during the first year of follow-up.

RESULTS

729 AF patients were included (57.1% male, median age 75 [IQR 67-81] years, median CHA₂ DS₂ -VASc and HAS-BLED of 3 [IQR 2-5] and 2 [IQR 1-2], respectively). 548 (75.2%) patients received OAC alone (318 [43.6%] on VKAs and 230 [31.6%] on DOACs). After 1 year, the use of OAC alone showed lower rates of any TE/ACS/cardiovascular death (3.0%/year; p < 0.001) compared to other regimens, and non-use of OAC alone (HR 4.18, 95% CI 2.12-8.27) was independently associated with any TE/ACS/cardiovascular death. Balancing the effects of treatment, the NNTnet to provide an overall benefit of OAC therapy was 24. The proportion of patients on OAC increased at 1 year (87% to 88.1%), particularly on DOACs (33.6% to 39.9%) (p = 0.015), with low discontinuation rates.

CONCLUSIONS

In this contemporary cohort of AF patients, OAC therapy was associated with better clinical outcomes at 1 year and positive NNTnet. OAC use slightly increased during the follow-up, with low discontinuation rates and higher prescription of DOACs.

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.

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.

Benefits and Harms of Low-Dose Rivaroxaban in Asian Patients With Atrial Fibrillation: A Systematic Review and Meta-analysis of Real-World Studies

Background: Low-dose prescription of rivaroxaban was common among patients with atrial fibrillation (AF) in Asia. However, the benefits and harms of rivaroxaban at a low dosage in Asian patients with AF remains unclear. Accordingly, we aimed to collect and summarize all available evidence to fill this important knowledge gap. Methods: In this systematic review and meta-analysis, we systematically searched databases of MEDLINE, EMBASE, and Cochrane Library for relevant studies from inception until February 23, 2021. Eligible retrospective nationwide or health insurance database studies or prospective registration studies that reported efficacy (stroke/systemic embolism), safety (major bleeding, intracranial hemorrhage, gastrointestinal bleeding), or other outcomes (myocardial infarction, death) of low-dose rivaroxaban in comparison with warfarin in AF patients were enrolled. Data extraction and study quality assessment were conducted by two authors independently. Low dosing of rivaroxaban (15/10 mg) was defined as the received dose lower than the recommended dose (20 mg) approved in most districts. Hazard ratio (HR) with 95% confidence intervals (95% CIs) was pooled using a random-effect model. Subgroup analyses were conducted according to different dose regimens. Sensitivity analyses were conducted by sequential elimination of each study from the pool. Since potential effect modifiers (patient demographics, differences of each study, and others) may lead to bias in primacy outcomes, we performed a meta-regression analysis to explore the influence of these factors on the primary efficacy and safety outcomes. Results: Totally, 12 studies involving 292,815 Asian patients with AF were included. All studies were detected as low to moderate risk bias. Low-dose rivaroxaban treatment in Asian AF patients was associated with a reduced risk of stroke/systemic embolism (HR: 0.76, 95% CI: 0.70-0.84, I ² : 57.8%), major bleeding (HR: 0.72, 95% CI: 0.62-0.84, I ² : 81.5%), and all-cause death (HR: 0.65, 95% CI: 0.58-0.73, I ² : 81.7%) when compared with warfarin. Furthermore, consistent results were observed among different dose regimens (10/15/20 mg) in all the clinical outcomes (P _interaction > 0.05 for each outcome). Meta-regression analysis failed to detect any potential confounding to impact the primacy outcomes. Conclusion: Insights from the present meta-analysis, we found that low-dose rivaroxaban, even at a dosage of 10 mg daily, was associated with a reduced risk of stroke/SE and bleeding than warfarin in Asian AF patients. However, owing to considerable heterogeneity among included studies, further prospective studies are required to confirm these findings.