Effectiveness and Safety of Rivaroxaban 15 or 20 mg Versus Vitamin K Antagonists in Nonvalvular Atrial Fibrillation

Outcomes Associated With Left Atrial Appendage Occlusion Via Implanted Device in Atrial Fibrillation

OBJECTIVE

To compare outcomes after left atrial appendage occlusion (LAAO) via implanted device vs no LAAO in a matched cohort of patients with atrial fibrillation (AF).

METHODS

This longitudinal retrospective cohort study was based on the national database covering hospital care for the entire French population. Adults (≥18 years of age) who had been hospitalized with AF (January 1, 2015, to January 1, 2020) who underwent LAAO were identified. Propensity score matching was used to control for potential confounders of the treatment-outcome relationship. The primary outcome was a composite of ischemic stroke, major bleeding, or all-cause death during follow-up.

RESULTS

After propensity score matching, 1216 patients with AF who were treated with LAAO were matched with 1216 controls (patients AF who were not treated with LAAO). Mean follow-up was 14.5 months (median, 13 months; IQR, 7-21 months). Patients with LAAO had a lower risk of the composite outcome (HR, 0.48; 95% CI, 0.42 to 0.55). Total events (309 for LAAO vs 640 for controls) and event rates (23.3% vs 44.0%/year, respectively) were lower for LAAO, driven primarily by a decreased risk of all-cause death (HR, 0.39; 95% CI, 0.33 to 0.46; P<.0001), whereas ischemic stroke risk was higher (HR, 1.75; 95% CI, 1.17 to 2.64). Significant interactions were observed in subgroups with a history of ischemic stroke (P<.001) and of bleeding (P=.002).

CONCLUSION

Among AF patients at high bleeding risk, our nationwide study highlights a high risk of clinical events during follow-up. LAAO appeared less effective than no LAAO in preventing stroke but more effective in preventing death. Left atrial appendage occlusion is particularly effective in patients with previous ischemic stroke or any episode of bleeding.

Patterns of atrial fibrillation anticoagulation with rivaroxaban - 7-year follow-up from the Dresden NOAC registry

INTRODUCTION

Data on long-term effectiveness and safety of rivaroxaban for stroke prevention in atrial fibrillation (SPAF) are scarce and not available from randomized clinical trials.

METHODS

We used data from the prospective, non-interventional DRESDEN NOAC REGISTRY to evaluate rates of stroke/transient ischaemic attack (TIA)/systemic embolism (SE) and ISTH major bleeding, in general and changes of event patterns over time.

RESULTS

Between 1st October 2011 and 31st December 2022, 1204 SPAF patients receiving rivaroxaban were followed for 6.7 ± 3.4 years with a mean rivaroxaban exposure of 4.9 ± 3.5 years. During follow up, intention-to treat rates of stroke/TIA/SE were 3.5/100 pt. years (95 % CI 2.5-4.7) in the first year and fell to 1.6/100 pt. years (95 % CI 1.2-2.0) in years 2-5 and 2.1/100 pt. years (95 % CI 1.6-2.7) after 5 years. Similarly, on-treatment event rates fell from 2.4/100 pt. years (95 % CI 1.5-3.5) to 1.1 (95 % CI 0.7-1.5) and 1.6 (95 % CI 1.0-2.3), respectively. Major bleeding rates on treatment were 3.5/100 pt. years in the first treatment year (95 % CI 2.5-4.8) and 2.7 (95 % CI 2.2-3.4) and 3.5 (95 % CI 2.7-4.6) in the periods 2-5 and > 5 years, respectively. Of note, rates of fatal bleeding were low throughout follow-up (0.2 vs. 0.2 vs. 0.1/100 pt. years).

CONCLUSIONS

Our results demonstrate the long-term effectiveness and safety of rivaroxaban therapy in unselected SPAF patients in daily care. Our data indicate that patterns of cardiovascular events remain constant over many years. In contrast, bleeding patterns change over time, possibly due to effects of co-morbidities in an ageing population.

The impact of ABCB1, CYP3A4/5 and ABCG2 gene polymorphisms on rivaroxaban trough concentrations and bleeding events in patients with non-valvular atrial fibrillation

BACKGROUND

The influence of genetic factors on the pharmacokinetics and clinical outcomes of rivaroxaban in patients with non-valvular atrial fibrillation (NVAF) is poorly understood. This study aimed to explore the effects of CYP3A4/5, ABCB1, and ABCG2 gene polymorphisms on the trough concentrations and the bleeding risk of rivaroxaban in NVAF patients.

PATIENTS AND METHODS

This study is a prospective multicenter study. The patient's blood samples were collected to detect the steady-state trough concentrations of rivaroxaban and gene polymorphisms. We visited the patients regularly at month 1, 3, 6, and 12 to record bleeding events and medications.

RESULTS

A total of 95 patients were enrolled in this study, and 9 gene loci were detected. For the dose-adjusted trough concentration ratio (C_trough/D) of rivaroxaban, the homozygous mutant type was significantly lower than wild type at ABCB1 rs4148738 locus (TT vs. CC, P = 0.033), and the mutant type was significantly lower than the wild type at ABCB1 rs4728709 locus (AA + GA vs. GG, P = 0.008). ABCB1 (rs1045642, rs1128503), CYP3A4 (rs2242480, rs4646437), CYP3A5 (rs776746), and ABCG2 (rs2231137, rs2231142) gene polymorphisms had no significant effect on the C_trough/D of rivaroxaban. For the bleeding events, we found that there were no significant differences among genotypes of all gene loci.

CONCLUSION

This study found for the first time that ABCB1 rs4148738 and rs4728709 gene polymorphisms had a significant impact on the C_trough/D of rivaroxaban in NVAF patients. CYP3A4/5, ABCB1, and ABCG2 gene polymorphisms were not associated with the bleeding risk of rivaroxaban.

Across-Country Variations of Real-World Data and Evidence for Drugs: A 5-European-Country Study

OBJECTIVES

This study aimed to describe the role of real-world data (RWD) and real-world evidence (RWE) in health technology assessment (HTA) in 5 European countries and to identify the hurdles to the acceptance of RWE and suggest directions toward its more effective use.

METHODS

Authors from France, Germany, Italy, and Sweden used a common template to extract evidence. For England, the Cancer Drugs Fund was described and analyzed as a particular model for the use of RWD to provide evidence for coverage decisions and managed entry agreements.

RESULTS

In all countries except Germany, HTA bodies acknowledged the relevance of RWD/RWE to address postlaunch uncertainties. In Germany, evidence from randomized controlled trials remains the gold standard, and evidence based on RWD is generally rejected. Multiple sources of RWD exist, but the quality, the immediate relevance of existing sources, and their interoperability limit their adaptation to the specifics of a given drug. This leads to skepticism about the validity of the evidence. Timing is also a key issue: the production of evidence may not be synchronized with the HTA and pricing bodies' agendas. The Cancer Drugs Fund case emphasizes that a strong partnership among all stakeholders and a pragmatic use of existing data, alongside clinical evidence provided by companies, are key success factors.

CONCLUSIONS

A continuous investment in national health information systems is a key issue for providing valid RWE. Processes and aids to guide the acceptability and usage of RWE derived from pairing between sources and questions are essential.

Real-world data and evidence in health technology assessment: When are they complementary, substitutes, or the only sources of data compared to clinical trials?

Within the life-cycle assessment of health technologies, real-world data (RWD) have until now been of secondary importance to clinical trial data. The availability of massive, better quality RWD, particularly with the emergence of connected devices, the improvement of methods for characterizing populations, make it possible to have a better insight into the effects of treatment, sometimes on a national scale the importance of RWD is likely to progress in the eyes of health technology assessors, going from being traditionally complementary to possibly replacing clinical trial data. This is the fundamental question that the round table, involving experts from the academic and/or hospital, institutional, and industrial worlds, set out to answer. This work served first to establish the current role of RWD in health technology assessment, by distinguishing the main purposes of RWD, the timing of the evaluation in relation to the life cycle of the technology, and then according to the party commissioning or receiving the outcomes of RWD-based studies. Secondly, the round table proposed six general recommendations for more intensive and decisive use of RWD in the assessment and decision-making process.

A retrospective study of real-world effectiveness and safety of rivaroxaban in patients with non-valvular atrial fibrillation and venous thromboembolism in Saudi Arabia

Background

Real-world evidence on factor Xa inhibitor (rivaroxaban) prescribing patterns, safety, and efficacy in patients with non-valvular atrial fibrillation (NVAF) and venous thromboembolism (VTE) is rare. Herein, we sought to examine the above outcomes in the largest academic center in the Kingdom of Saudi Arabia (KSA).

Methods

This is a retrospective observational study designed to examine the prescribing pattern, safety and real-world effectiveness of the factor Xa inhibitor rivaroxaban in patients with NVAF and VTE. Data on rivaroxaban prescriptions were collected and analyzed. Bleeding outcomes were defined as per the International Society on Thrombosis and Hemostasis (ISTH) definition.

Results

A total of 2,316 patients taking rivaroxaban recruited through several departments of King Saud University Medical City (KSUMC). The mean age was 61 years (±17.8) with 55% above the age of 60 and 58% were females. Deep vein thrombosis and pulmonary embolism (VTE) was the most prevalent reason for prescribing rivaroxaban, followed by NVAF. A total daily dosage of 15 mg was given to 23% of the patients. The incidence rate of recurrent thrombosis and recurrent stroke was 0.2%. Furthermore, rivaroxaban had a 0.04 percent incidence rate of myocardial infarction. Half of the patients with recurrent thrombosis and stroke were taking 15 mg per day. The incidence rate of major bleeding was 1.1%. More over half of the patients who experienced significant bleeding were taking rivaroxaban at a dosage of 20 mg per day. According to the HAS-BLED Score (>2 score), 48 percent of patients who experienced significant bleeding had a high risk of bleeding. Non-major bleeding occurred in 0.6% of cases. Similarly, 40% of patients with non-major bleeding were taking rivaroxaban at a dosage of 20 mg per day. According to the HAS-BLED Score, just 6.6% of these individuals had a high risk of bleeding. 93.4% of the patients, on the other hand, were at intermediate risk.

Conclusion

The prescription of rivaroxaban in this real-life cohort study differs from the prescribing label and the outcomes of a phase 3 randomised clinical trial. However, for individuals with VTE and NVAF, the 20 mg dose looked to be more efficacious than the pivotal trial outcomes. Furthermore, among patients with VTE and NVAF, rivaroxaban was linked to a decreased incidence of safety events such as recurrent thrombosis, recurrent stroke, MI, major bleeding, and non-major haemorrhage in a real-world environment.

Utility of automated data-adaptive propensity score method for confounding by indication in comparative effectiveness study in real world Medicare and registry data

Background

Confounding by indication is a serious threat to comparative studies using real world data. We assessed the utility of automated data-adaptive analytic approach for confounding adjustment when both claims and clinical registry data are available.

Methods

We used a comparative study example of carotid artery stenting (CAS) vs. carotid endarterectomy (CEA) in 2005–2008 when CAS was only indicated for patients with high surgical risk. We included Medicare beneficiaries linked to the Society for Vascular Surgery’s Vascular Registry >65 years old undergoing CAS/CEA. We compared hazard ratios (HRs) for death while adjusting for confounding by combining various 1) Propensity score (PS) modeling strategies (investigator-specified [IS-PS] vs. automated data-adaptive [ada-PS]); 2) data sources (claims-only, registry-only and claims-plus-registry); and 3) PS adjustment approaches (matching vs. quintiles-adjustment with/without trimming). An HR of 1.0 was used as a benchmark effect estimate based on CREST trial.

Results

The cohort included 1,999 CAS and 3,255 CEA patients (mean age 76). CAS patients were more likely symptomatic and at high surgical risk, and experienced higher mortality (crude HR = 1.82 for CAS vs. CEA). HRs from PS-quintile adjustment without trimming were 1.48 and 1.52 for claims-only IS-PS and ada-PS, 1.51 and 1.42 for registry-only IS-PS and ada-PS, and 1.34 and 1.23 for claims-plus-registry IS-PS and ada-PS, respectively. Estimates from other PS adjustment approaches showed similar patterns.

Conclusions

In a comparative effectiveness study of CAS vs. CEA with strong confounding by indication, ada-PS performed better than IS-PS in general, but both claims and registry data were needed to adequately control for bias.

Concurrent use of statins decreases major bleeding and intracerebral hemorrhage in non-valvular atrial fibrillation patients taking direct oral anticoagulants—A nationwide cohort study

Background

Statins are frequently prescribed with direct oral anticoagulants (DOACs), and previous studies have raised concerns about the increased risk of intracerebral hemorrhage or other major bleeding in concurrent statins and DOACs use. The objective of this study is to evaluate the risk of major bleeding in non-valvular atrial fibrillation patients taking DOACs with or without statins.

Methods

This nationwide, retrospective cohort study used data from the Taiwan National Health Insurance Research Database, enrolled a total of 90,731 non-valvular atrial fibrillation patients receiving rivaroxaban, dabigatran, apixaban or edoxaban from January 1st, 2012 to December 31st, 2017. Major bleeding was defined as a hospitalization or emergency department visit with a primary diagnosis of intracerebral hemorrhage, gastrointestinal tract bleeding, urogenital tract bleeding, or other sites of bleeding. Adjusted incidence rate ratios (IRR) and differences of major bleeding between person-quarters of DOACs with or without statins were estimated using a Poisson regression and inverse probability of treatment weighting using the propensity score.

Results

50,854 (56.0%) of them were male with a mean age of 74.9 (SD, 10.4) years. Using DOACs without statins as a reference, the adjusted IRR for all major bleedings in concurrent use of DOACs and statins was 0.8 (95% CI 0.72–0.81). Lower major bleeding risk was seen in both low-to-moderate-intensity statins (IRR: 0.8, 95% CI 0.74–0.84) and high-intensity statins (IRR: 0.8, 95% CI 0.74–0.88). Concurrent use of DOACs and statins decreased the risk for intracerebral hemorrhage with an IRR of 0.8 (95% CI 0.66–0.93), and gastrointestinal tract bleeding with an IRR of 0.7 (95% CI 0.69–0.79). The protective effect of statins on intracerebral hemorrhage was observed only in female patients (IRR 0.67, 95% CI 0.51–0.89), but not in male patients (IRR 0.87, 95% CI 0.70–1.08).

Conclusions

Among non-valvular atrial fibrillation patients who were taking DOACs, concurrent use of statins decreased major bleeding risk, including intracerebral hemorrhage and gastrointestinal tract bleeding. Considering this and other cardioprotective effects, statins should be considered in all eligible patients prescribed with DOACs.

Current Therapeutic Approach to Atrial Fibrillation in Patients with Congenital Hemophilia

Cardiovascular disease in hemophiliacs has an increasing prevalence due to the aging of this population. Hemophiliacs are perceived as having a high bleeding risk due to the coagulation factor VIII/IX deficiency, but it is currently acknowledged that they also have an important ischemic risk. The treatment of atrial fibrillation (AF) is particularly challenging since it usually requires anticoagulant treatment. The CHA2DS2-VASc score is used to estimate the risk of stroke and peripheral embolism, and along with the severity of hemophilia, guide the therapeutic strategy. Our work provides the most complete, structured, and updated analysis of the current therapeutic approach of AF in hemophiliacs, emphasizing that there is a growing interest in therapeutic strategies that allow for short-term anticoagulant therapy. Catheter ablation and left atrial appendage occlusion have proven to be efficient and safe procedures in hemophiliacs, if appropriate replacement therapy can be provided.

Population Pharmacokinetics of Rivaroxaban in Chinese Patients with Non-Valvular Atrial Fibrillation: A Prospective Multicenter Study

BACKGROUND AND OBJECTIVE

Rivaroxaban is a novel oral anticoagulant widely used for thromboprophylaxis in patients with non-valvular atrial fibrillation (NVAF). The present study aimed to develop a population pharmacokinetic (PPK) model for rivaroxaban in Chinese patients with NVAF.

METHODS

We performed a prospective multicenter study. The plasma concentration of rivaroxaban was directly detected by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and indirectly by rivaroxaban-calibrated chromogenic anti-Xa assay (STA^®). Gene polymorphisms were detected by MassARRAY single nucleotide polymorphism genotyping technology. Nonlinear mixed-effects modeling was used to develop the PPK model for rivaroxaban in patients with NVAF, and we simulated the steady-state rivaroxaban exposures under different dosing strategies in different covariate levels.

RESULTS

A total of 150 patients from five centers were recruited, including 263 plasma concentrations detected by HPLC-MS/MS, 2626 gene polymorphisms, and 131 plasma concentrations detected by anti-Xa assay. In our study, an oral one-compartment model was used to describe the pharmacokinetics of rivaroxaban in patients with NVAF. In the final model, the estimated apparent clearance (CL/F) and volume of distribution (V/F) were 5.79 L/h (relative standard error [RSE] 4.4%) and 51.5 L (RSE 5.0%), respectively. Covariates in the final model included creatinine clearance, total bilirubin, rs4728709, and body weight. The simulation results showed that in the 15 mg once-daily dosing regimen, in most instances the maximum plasma concentration at steady state (C_max,ss) and trough plasma concentration at steady state (C_min,ss) were in the target range for different covariate levels. When patients were administered rivaroxaban 15 or 20 mg once daily, the C_max,ss and C_min,ss in the different bodyweight levels were also in the target range. For patients with the ABCB1 rs4728709 mutation, the C_min,ss in the 10, 15, and 20 mg once-daily dosing regimens were lower than the target range. The anti-Xa assay was highly linearly correlated with the HPLC-MS/MS method [y = 1.014x - 2.4648 (R² = 0.97)].

CONCLUSIONS

Our study was the first multicenter PPK model for rivaroxaban in Chinese patients with NVAF (Alfalfa-RIVAAF-PPK). The study found that 15 mg once daily may be suitable as the principal rivaroxaban dose for Chinese patients with NVAF. For patients with the rs4728709 mutation, it may be necessary to examine insufficient anticoagulation. We found that the rivaroxaban-calibrated chromogenic anti-Xa assay and HPLC-MS/MS method were highly linearly correlated. Prospective studies with larger sample sizes and real-world studies are needed for further verification.

A Comparative Study of the Clinical Benefits of Rivaroxaban and Warfarin in Patients With Non-valvular Atrial Fibrillation With High Bleeding Risk

Objective

To compare the clinical benefits of rivaroxaban and warfarin in patients with non-valvular atrial fibrillation (NVAF) with high bleeding risk.

Methods

A retrospective study was conducted on patients with high bleeding risk NVAF who were hospitalized at the First Affiliated Hospital of Zhengzhou University between May 31, 2016 and May 31, 2019 and took at least rivaroxaban and warfarin. The clinical benefits of both drugs were assessed by efficacy benefit and safety risk. The primary efficacy benefit was a composite end point for stroke (both ischemic and hemorrhagic) and systemic embolism. The secondary efficacy end points were death and myocardial infarction (MI). The principal safety end point was the composite end point of fatal bleeding and critical organ bleeding.

Results

A total of 1,246 patients with high bleeding risk were enrolled, including 787 patients in the rivaroxaban group and 459 patients in the warfarin group. Results of the primary efficacy benefit endpoint were obtained from 104 patients (13.2%) in the rivaroxaban group and 88 (19.2%) patients in the warfarin group (hazard ratio [HR]: 0.681; 95% confidence interval [CI]: 0.512–0.906; P &lt; 0.001 for non-inferiority). The principal safety end points were observed in 49 (6.23%) patients in the rivaroxaban group and in 55 (11.98%) patients in the warfarin group (HR: 0.469 in the rivaroxaban group; 95% CI: 0.314–0.702; P &lt; 0.001). With respect to secondary efficacy and benefit endpoints, 28 (3.56%) patients in the rivaroxaban group and 22 (4.79%) patients in the warfarin group died, with an HR of 0.760 (95% CI: 0.435–1.329; P = 0.336); 32 (4.07%) patients in the rivaroxaban group; and 26 (5.66%) patients in the warfarin group had MI, with an HR of 1.940 (95% CI: 0.495–1.069, P = 0.254) in the rivaroxaban group.

Conclusions

Rivaroxaban is non-inferior to warfarin in the prevention of stroke and systemic embolism in patients with high blood NVAF. Rivaroxaban is superior to warfarin in reducing fatal bleeding and bleeding in critical organs.

Clinical Trial Registration

Chinese Clinical Trials Registry, identifier ChiCTR2100052454.

Patients with stable coronary artery disease and type 2 diabetes but without prior myocardial infarction or stroke and THEMIS-like patients: real-world prevalence and risk of major outcomes from the SNDS French nationwide claims database

AIM AND HYPOTHESES

The THEMIS randomized trial compared ticagrelor plus aspirin versus placebo plus aspirin for patients with stable coronary artery disease and type 2 diabetes mellitus (CAD-T2DM), and without prior myocardial infarction (MI) or stroke. The aim of the study was to quantify the size of the CAD-T2DM population without prior MI or stroke population in a real-world setting, and more specifically populations with similar THEMIS selection criteria (THEMIS-like and THEMIS-PCI-like populations), as well as their risk of major outcomes in current practice.

METHODS

A 2-year follow-up cohort study included all CAD-T2DM without MI/stroke prevalent patients on January 1st, 2014 in the SNDS French nationwide claims database. The THEMIS-like population concerned those ≥ 50 years of age with similar THEMIS inclusion and exclusion criteria. Prevalence was standardized to the European population. The cumulative incidence function was used to estimate the incidence of clinical outcomes (MI, ischemic stroke, and major bleeding according to the TIMI classification) with death as competing risk, and the Kaplan-Meier estimate for all-cause death and a composite outcome of MI, stroke and all-cause death.

RESULTS

From a population of about 50 million adults, the prevalence of CAD-T2DM without MI/stroke, THEMIS-like and THEMIS-PCI-like populations was respectively at 6.04, 1.50 and 0.27 per 1000 adults, with a mean age of 72.7, 72.3 and 70.9 years and less comorbidities and diabetic complications for the THEMIS-like and THEMIS-PCI-like population. The 2-year cumulative incidence was respectively 1.7%, 1.3% and 1.6% for MI, 1.7%, 1.5% and 1.4% for stroke, 4.8%, 3.1% and 2.9% for major bleeding, 13.6%, 9.7% and 6.8% for all-cause death, and 16.2%, 12.0% and 9.5% for the composite outcome.

CONCLUSION

THEMIS-like prevalence was estimated at 1.50 per 1,000 adults, representing about a quarter of CAD-T2DM without MI/stroke patients, and 0.27 per 1000 adults for the THEMIS-PCI-like populations. In current French practice, the median age of both these populations was about 5-6 years older than in the THEMIS trial, with a 2-year incidence of major outcomes between two or four time above the ones of the placebo arm of the THEMIS trial using very close definitions. Registration No. EUPAS27402 ( http://www.ENCEPP.eu ).

Direct Oral Anticoagulants versus Warfarin in Octogenarians with Nonvalvular Atrial Fibrillation: A Systematic Review and Meta-Analysis

Direct oral anticoagulants (DOACs) have been demonstrated to be more effective and safer than vitamin-K antagonist (VKA) for stroke prevention in patients with nonvalvular atrial fibrillation (AF). This meta-analysis aims to assess the effect of DOACS vs. VKA in patients ≥ 80 and AF. Primary endpoints were stroke or systemic embolism and all-cause death. Secondary endpoints included major bleeding, intracranial bleeding, and gastrointestinal bleeding. A random-effects model was selected due to significant heterogeneity. A total of 147,067 patients from 16 studies were included, 71,913 (48.90%) treated with DOACs and 75,154 with VKA (51.10%). The stroke rate was significantly lower in DOACs group compared with warfarin group (Relative risk (RR): 0.72; 95% confidence interval (CI): 0.63-0.82; p < 0.001). All-cause mortality was significantly lower in DOACs group compared with warfarin group (RR: 0.82; 95% CI: 0.70-0.96; p = 0.012). Compared to warfarin, DOACs were not associated with reductions in major bleeding (RR: 0.85, 95% CI 0.69-1.04; p = 0.108) or gastrointestinal bleeding risk (RR: 1.08, 95% CI 0.76-1.53; p = 0.678) but a 43% reduction of intracranial bleeding (RR: 0.47, IC 95% 0.36-0.60; p < 0.001) was observed. Our meta-analysis demonstrates that DOACs are effective and safe with statistical superiority when compared with warfarin in octogenarians with AF.

Standard- vs. low-dose rivaroxaban in patients with atrial fibrillation: a systematic review and meta-analysis

PURPOSE

Low-dose rivaroxaban is often given to patients with atrial fibrillation (AF) around the world, but the rationale for its use remains unclear. We aimed to compare the efficacy and safety of standard- or low-dose rivaroxaban in patients with AF through systematic review of literature with meta-analysis.

METHODS

We searched PubMed, Web of Science, EMBASE, Clinical Trials.gov, the Cochrane Library, and Bayer trial website from inception of each database until June 2020. Randomized controlled trials (RCTs) and cohort studies were included in the meta-analysis. A random-effects model was employed to calculate the pooled effect estimates.

RESULTS

Two RCTs and 17 cohort studies were included in the qualitative analysis. Indirect comparison of RCTs showed no significant difference between the two rivaroxaban dosages in risk of efficacy or safety outcomes (p > 0.05). Indirect comparison of cohort studies showed a lower risk of MACE among Caucasians in standard-dose group (HR 0.779; 95% CI 0.687-0.884; p < 0.001). Bleeding outcomes did not differ significantly between the two dosage regimens in Asian or Caucasian populations, except that the standard dose was associated with higher risk of major bleeding among elderly Caucasian patients (HR 1.329; 95% CI 1.141-1.547; p < 0.001). The quality of evidence was rated ranging from very low to low for all the efficacy and safety outcomes.

CONCLUSION

In Caucasians with AF, standard-dose rivaroxaban may prevent MACE significantly better than low-dose treatment. Further studies in Asians are needed to verify the advantages of the standard dose.

Real-life data of major and minor bleeding events with direct oral anticoagulants in the one-year follow-up period: The NOAC-TURK study

OBJECTIVE

This study aimed to evaluate the safety of direct oral anticoagulants (DOACs) in patients with non-valvular atrial fibrillation (NVAF) during daily clinical practice.

METHODS

This was a prospective study conducted between January 01, 2016, and April 01, 2017, in patients aged ≥18 years with a diagnosis of NVAF. We performed the study in 9 clinical centers from different regions of Turkey, and the mean follow-up period was 12+2 months. We investigated major and minor bleeding events of DOAC.

RESULTS

A total of 1807 patients with NVAF were enrolled. The mean age of the patients was 73.6±10.2 years, CHA2DS2-VASc score was 3.6±1.4, and HAS-BLED score was 2±1.2. The most frequently prescribed DOAC was dabigatran 110 mg bid in 409 (22.6%) patients. The patients on apixaban 2.5 mg bid were older (p<0.001). Patients on rivaroxaban 15 mg od also had a higher prevalence of chronic renal failure, 46 (16.7%) patients. A total of 205 (11.4%) bleeding events were observed; among these, 34 (1.9%) patients had major bleeding and 171 (9.4%) patients had minor bleeding. The major and minor bleeding events were 2/273 (0.7%) and 30/273 (10.9%) in patients receiving dabigatran 150 mg bid, 13/409 (3%) and 44/409 (10.7%) in patients receiving dabigatran 110 mg bid, 4/385 (1%) and 42/385 (10.9%) in patients receiving rivaroxaban 20 mg od, 8/276 (2.9%) and 27/276 (9.7%) in patients receiving rivaroxaban 15 mg od, 3/308 (0.9%) and 14/308 (4.5%) in patients receiving apixaban 5 mg bid, 4/156 (2.5%) and 14/156 (9%) in patients receiving apixaban 2.5 mg bid, respectively. The total bleeding events were 17 (5.6%) in patients receiving apixaban 5 mg, less than those receiving other DOACs. On multivariate analyses, rivaroxaban 20 mg od (p=0.002), ATRIA and HAS-BLED scores, and peripheral artery disease were independent indicators of bleeding. The most frequent location of major bleeding was the gastrointestinal system (GIS) [17 (0.9%) patients], and the most frequent location of minor bleeding was the gingiva [45 (2.5%) patients].

CONCLUSION

This study showed that similar results as the previous real-life study; however, we had some different results, such as the GIS tract bleeding was more frequent in patients receiving dabigatran 110 mg bid. The major and intracranial bleeding events were similar for different DOACs; and among DOACs, only rivaroxaban 20 mg od was associated with a high risk of bleeding.

The Multifaceted Interplay between Atrial Fibrillation and Myocardial Infarction: A Review

This review was conducted to emphasize the complex interplay between atrial fibrillation (AF) and myocardial infraction (MI). In type 1 (T1) MI, AF is frequent and associated with excess mortality. Moreover, AF after hospital discharge for T1MI is not rare, suggesting the need to improve AF screening and to develop therapeutic strategies for AF recurrence. Additionally, AF is a common trigger for type 2 MI (T2MI), and recent data have shown that tachyarrhythmia or bradyarrhythmia could be a causal factor in, respectively, 13-47% or 2-7% of T2MI. In addition, AF is involved in T2MI pathogenesis as a result of severe anemia related to anticoagulants. AF is also an underestimated and frequent cause of coronary artery embolism (CE), as a situation at risk of myocardial infarction with non-obstructive coronary arteries. AF-causing CE is difficult to diagnose and requires specific management. Moreover, patients with both AF and chronic coronary syndromes represent a therapeutic challenge because the treatment of AF include anticoagulation, depending on the embolic risk, and ischemic heart disease management paradoxically includes antiplatelet therapy.

Association of Ischemic Stroke, Major Bleeding, and Other Adverse Events With Warfarin Use vs Non-vitamin K Antagonist Oral Anticoagulant Use in Patients With Atrial Fibrillation With a History of Intracranial Hemorrhage

IMPORTANCE

Current guidelines recommend the use of non-vitamin K antagonist oral anticoagulants (NOACs) for stroke prevention in patients with atrial fibrillation (AF). Data regarding warfarin sodium use compared with NOAC use in patients with AF with a history of intracranial hemorrhage (ICH) are limited.

OBJECTIVE

To compare the clinical outcomes of warfarin use and NOAC use in patients with AF with a history of ICH using a nationwide cohort with AF.

DESIGN, SETTING, AND PARTICIPANTS

A nationwide cohort study from January 1, 2012, to December 31, 2016, was performed using data from the Taiwan National Health Insurance Research Database. The dates of analysis were July 1 to September 1, 2019. The study population comprised patients with AF with a history of ICH and a CHA2DS2-VASc score (congestive heart failure, hypertension, age ≥75 years [doubled], diabetes, prior stroke/transient ischemic attack/thromboembolism [doubled], vascular disease [prior myocardial infarction, peripheral artery disease], age 65-74 years, sex category [female]) of at least 1 for men or at least 2 for women who had received warfarin or NOACs. The clinical outcomes were examined using Cox proportional hazards regression analyses among the study population before and after propensity score matching.

EXPOSURES

Oral anticoagulation with warfarin or NOACs.

MAIN OUTCOMES AND MEASURES

The clinical outcomes measured were all-cause mortality, ischemic stroke, ICH, major bleeding, and adverse events.

RESULTS

The study cohort included 4540 patients (mean [SD] age, 76.0 [10.5] years; 2653 men [58.4%]), with 1047 patients receiving warfarin (mean [SD] age, 75.1 [11.4] years; 571 men [54.5%]) and 3493 patients receiving NOACs (mean [SD] age, 76.3 [10.2] years; 2082 men [59.6%]). Compared with warfarin use, NOAC use was associated with statistically significantly lower risk of all-cause mortality (adjusted hazard ratio [aHR], 0.517; 95% CI, 0.457-0.585), ICH (aHR, 0.556; 95% CI, 0.389-0.796), and major bleeding (aHR, 0.645; 95% CI, 0.525-0.793), whereas the rate of ischemic stroke was similar in the 2 groups (aHR, 0.879; 95% CI, 0.678-1.141). These results were generally consistent after propensity score matching among 973 patients in each group.

CONCLUSIONS AND RELEVANCE

Among patients with AF with prior ICH, NOAC use was associated with lower rates of ICH and major bleeding compared with warfarin use, whereas the rate of ischemic stroke was similar in the 2 groups. Among patients with AF with prior ICH, NOACs could be the preferred choice for stroke prevention.

Pharmacoepidemiology

At the time of their marketing authorization, the effects of drugs and especially their efficacy have been mostly studied in randomized controlled clinical trials (RCT), comparing them to placebo or to existing drugs. However, RCT are by nature limited in their extent, and the often stringent inclusion and exclusion criteria destined to provide for homogeneous study populations reduce the generalizability of RCT results.The post-authorization evaluation of drugs (pharmacoepidemiology or real-world evidence (RWE)) covers the description of drug utilization and population risks or benefits of these drugs after they have been marketed and provided to their target populations. Though field studies have existed for a long time, modern pharmacoepidemiology has been made possible essentially by the emergence of large population databases compiled from claims data or electronic health records. The methods can be exposure or disease-based cohorts or event-driven case-based studies, tailored to the specific questions to be answered. They rely on scrupulous analysis and execution of impeccable methodology, to ensure the most reliable results possible.Pharmacoepidemiology requires knowledge of the pharmacology of drugs, of the clinical aspects of diseases and disease management, and of the epidemiological methods that can apply.