Anticoagulation In Nonvalvular Atrial Fibrillation Research Articles

New oral anticoagulants for nonvalvular atrial fibrillation with stable coronary artery disease: A meta-analysis.

New oral anticoagulants (NOACs) are effective and safe in patients with nonvalvular atrial fibrillation (NVAF). Limited evidence is available regarding outcomes for NVAF patients with stable coronary artery disease (CAD). A systematic search of Medline, Embase, and the Cochrane Register was performed. Two reviewers independently performed data extraction and quality assessment using the Cochrane Collaboration risk-of-bias assessment tool. We evaluated all primary publications and secondary analyses comparing NOACs with any other OAC agent for preventing stroke in patients with both NVAF and stable CAD from phase III clinical randomized control trials. The primary outcomes were stroke, systemic embolism (SE), major bleeding, and intracranial hemorrhage (ICH), and the secondary outcomes were cardiovascular (CV) death, all-cause death, and myocardial infarction (MI). Four articles with a total of 19266 patients were included in this study. The pooled results showed a relative risk for stroke/SE with NOACs of 0.83 (95% confidence interval [CI]: 0.71-0.97), for major bleeding 0.85 (95% CI: 0.63-1.14), for ICH 0.36 (95% CI: 0.19-0.54), for MI 1.00 (95% CI: 0.82-1.20), for CV death 0.94 (95% CI: 0.83-1.06), and for all-cause death 0.95 (95% CI: 0.85-1.07). NOACs were effective in preventing stroke/SE and reducing the risk of ICH in patients with both NVAF and CAD.

Managing Ischemic Stroke in Patients Already on Anticoagulation for Atrial Fibrillation: A Nationwide Practice Survey

Background and purposeWe sought to understand practice patterns in management of patients who have ischemic stroke while adherent to oral anticoagulation for non-valvular atrial fibrillation (NVAF) in the United States (US). MethodsWe distributed an iteratively revised online survey to US neurologists in May-June 2019. Survey questions focused on clinicians’ practices regarding diagnostic evaluation and secondary prevention after ischemic stroke in patients already on oral anticoagulation for NVAF. Standard descriptive statistics were used to summarize participants’ characteristics and responses. ResultsOf the 120 participating clinicians, 79% were attending physicians. Most respondents (66%) were trained in vascular neurology, and 79% were employed in hospital-based, academic settings. For patients with ischemic stroke despite anticoagulation, most respondents indicated that they obtain extracranial and intracranial vessel imaging (72% and 82%, respectively). Most respondents (83%) routinely change therapy to a direct oral anticoagulant (DOAC) for patients experiencing ischemic stroke while on warfarin. In cases of ischemic stroke while on a DOAC, 38% of respondents routinely switch agents, 42% do not routinely switch agents, and 20% routinely add an antiplatelet agent. In this scenario, 83% of respondents who switch agents indicated that the reason was a possible better response to a drug that acts through a different mechanism. The most common reason for not switching while on a DOAC was the lack of randomized trial data. ConclusionsThere is a high degree of variability in practice patterns among US neurologists caring for patients with ischemic stroke while already on oral anticoagulation for NVAF.

Correction to: Comparative Safety and Effectiveness of Oral Anticoagulants in Nonvalvular Atrial Fibrillation: The NAXOS Study.

Correction to: Comparative Safety and Effectiveness of Oral Anticoagulants in Nonvalvular Atrial Fibrillation: The NAXOS Study.

The differences of atrial thrombus locations and variable response to anticoagulation in nonvalvular atrial fibrillation with ventricular cardiomyopathy.

ObjectivesThis study aims to research the clinical features of atrial thrombi in patients with nonvalvular atrial fibrillation (AF).METHODSThis study included 191 patients of AF who had atrial thrombi. One hundred and twenty‐eight of them were assigned into nonventricular cardiomyopathy group (non‐VCM), and the remaining 63 into ventricular cardiomyopathy group (VCM). After atrial thrombi diagnosed, all patients had taken oral anticoagulant therapy. The resolution rates of thrombi within 12 months were compared between the two groups, as well as the locations of thrombi.ResultsOf all 191 patients, 161 had thrombi only detected in left atrial appendage (LAA), 20 in both left atrium (LA) and LAA, six in LA only, and four in right atrium only. More patients had thrombi out of LAA in the VCM group than in the non‐VCM group (30.2% vs 8.6%, P < .001). After propensity score matching, the atrial thrombi were resolved faster in the non‐VCM group than in the VCM group (mean time length: 22 ± 2 weeks vs 30 ± 3 weeks, P = .038), and the resolution rate within 12 months was higher in the non‐VCM group than in the VCM group (88.7% vs 61.4%, Log‐rank, P = .038). In Cox proportional hazards model, absence of ventricular cardiomyopathy was an independent predictor for the resolution of atrial thrombus (hazard ratio: 1.76; P = .035).ConclusionsThe patients of atrial fibrillation with ventricular cardiomyopathies have higher incidence of thrombosis in the body of left atrium or right atrium. And the resolution rate was lower in these patients.

Oral anticoagulants for nonvalvular atrial fibrillation in frail elderly patients: insights from the ARISTOPHANES study.

Patient frailty amongst patients with nonvalvular atrial fibrillation (NVAF) is associated with adverse health outcomes and increased risk of mortality. Additional evidence is needed to evaluate effective and safe NVAF treatment in this patient population. This subgroup analysis of the ARISTOPHANES study compared the risk of stroke/systemic embolism (S/SE) and major bleeding (MB) amongst frail NVAF patients prescribed nonvitamin K antagonist oral anticoagulants (NOACs) or warfarin. This comparative retrospective observational study of frail, older NVAF patients who initiated apixaban, dabigatran, rivaroxaban or warfarin from 01JAN2013-30SEP2015 was conducted using Medicare and 3 US commercial claims databases. To compare each drug, 6 propensity score-matched (PSM) cohorts were created. Patient cohorts were pooled from 4 databases after PSM. Cox models were used to estimate hazard ratios (HR) of S/SE and MB. Amongst NVAF patients, 34% (N=150487) met frailty criteria. Apixaban and rivaroxaban were associated with a lower risk of S/SE vs warfarin (apixaban: HR: 0.61, 95% CI: 0.55-0.69; rivaroxaban: HR: 0.79, 95% CI: 0.72-0.87). For MB, apixaban (HR: 0.62, 95% CI: 0.57-0.66) and dabigatran (HR: 0.79, 95% CI: 0.70-0.89) were associated with a lower risk and rivaroxaban (HR: 1.14, 95% CI: 1.08-1.21) was associated with a higher risk vs warfarin. Amongst this cohort of frail NVAF patients, NOACs were associated with varying rates of stroke/SE and MB compared with warfarin. Due to the lack of real-world data regarding OAC treatment in frail patients, these results may inform clinical practice in the treatment of this patient population.

A review of global health technology assessments of non-VKA oral anticoagulants in non-valvular atrial fibrillation

BackgroundThis review assessed global health technology assessment (HTA) reports and recommendations of non-vitamin K oral anticoagulants (NOACs) in non-valvular atrial fibrillation (NVAF). MethodsNHTA agency websites were searched for HTA reports evaluating NOACs versus NOACs or vitamin K antagonists. HTA methods and information on patient involvement/access were collected and empirically analyzed. ResultsThe review identified 38 unique HTA reports published between 2012 and 2017 in 16 countries including 11 in Europe. NOACs that were cost-effective per local willingness-to-pay (WTP) thresholds were positively recommended for the treatment of NVAF. WTP thresholds ranged from €20,000 to 69,000. Apixaban was recommended in 10/12 (83%) countries, dabigatran in 9/13 (69%) countries, and rivaroxaban in 10/13 (76%) over warfarin. Edoxaban was recommended in 5/7 (71%) countries. Economic evaluations and recommendations comparing NOACs were sparse (two or three countries per NOAC) and generally favored apixaban and edoxaban, followed by dabigatran. Eleven HTA reports from four countries considered the patient voice (Canada [n = 3], Scotland [n = 3], England [n = 4], Brazil [n = 1]); however, only 2/11 (18%) developed recommendations based on this. Among the reports with a positive recommendation, 26/30 (87%) featured a decision that aligned with the approved regulatory label. ConclusionsMost agencies recommended NOACs over warfarin for patients with NVAF. Few countries made statements recommending one NOAC over another. Given different WTP thresholds, a drug that is cost-effective in one market may not be in another. Therefore, the various NOAC recommendations from HTA agencies cannot be generalized across different countries.

Rivaroxaban Versus Warfarin in African American Patients with Nonvalvular Atrial Fibrillation

IntroductionBlack patients are under-represented in randomized trials evaluating oral anticoagulants in non-valvular atrial fibrillation (NVAF). We sought to evaluate the effectiveness and safety of rivaroxaban versus warfarin in African Americans with NVAF. MethodsWe performed an analysis using Optum® De-Identified Electronic Health Record (EHR) data from 1/1/2012–9/30/2018. We included adult African American patients with a diagnosis of NVAF who were anticoagulant-naïve during the 12-months prior to initiation of rivaroxaban or warfarin. Patients receiving rivaroxaban were 1:1 propensity score matched to warfarin patients. Our primary effectiveness and safety outcomes were the 2-year incidence rates (%/year) of stroke or systemic embolism (SSE) and major bleeding using an intention-to-treat approach. Cohorts were compared using doubly-robust Cox regression and reported as hazard ratios (HRs) with 95% confidence intervals (CIs). ResultsWe matched 4102 rivaroxaban and 4102 warfarin users with a median (interquartile range) available follow-up of 2.0 (0.9, 2.0) years. Median CHA2DS2-VASc and HASBLED scores were 3 (2, 4) and 2 (1, 3). Rivaroxaban use was associated with a lower risk of SSE (1.99 versus 2.48, HR = 0.77, 95%CI = 0.60–0.99), ischemic stroke (1.84 versus 2.37, HR = 0.76, 95%CI = 0.59–0.98) and major bleeding (4.22 versus 4.98, HR = 0.84, 95%CI = 0.70–0.99). No differences in intracranial hemorrhage or gastrointestinal bleeding were observed. Neither sensitivity analyses utilizing an on-treatment methodology nor inverse probability-of-treatment weighting showed significant differences in SSE or major bleeding between rivaroxaban and warfarin users. ConclusionsRivaroxaban appeared at least as effective and safe as warfarin when used to manage African American patients with NVAF in routine practice.

Medical Management for Secondary Stroke Prevention.

This article reviews the evidence base and recommendations for medical management for secondary stroke prevention. Recent developments for secondary stroke prevention include evidence to support the use of short-term dual antiplatelet therapy after minor stroke and transient ischemic attack, direct oral anticoagulants for nonvalvular atrial fibrillation, reversal agents for direct oral anticoagulant-associated hemorrhage, and aspirin rather than presumptive anticoagulation with a direct oral anticoagulant for embolic stroke of undetermined source. Most strokes are preventable. The mainstays of medical management for secondary stroke prevention include antihypertensive therapy; antithrombotic therapy, with antiplatelet agents for most stroke subtypes or anticoagulants such as warfarin or a direct oral anticoagulant for cardioembolic stroke specifically; cholesterol-lowering therapy, principally with statins, but with potential roles for ezetimibe or proprotein convertase subtilisin/kexin type 9 inhibitors in selected patients; and glycemic control to prevent microvascular complications from diabetes mellitus or pioglitazone in selected patients with insulin resistance but not diabetes mellitus.

A KINK IN THE SYSTEM: ENCOUNTERING AND CORRECTING A WATCHMAN PERIPROCEDURAL COMPLICATION

The WATCHMAN (WM), Left Atrial Appendage Closure Device (Boston Scientific), was approved by the FDA in March 2015 as an alternative for patients unsuitable for oral anticoagulants in non-valvular atrial fibrillation (AF). The WM delivery sheath utilizes three different curves (single, double,

Abstract WMP115: Hemorrhagic and Ischemic Stroke in Patients on Oral Anticoagulants for Nonvalvular Atrial Fibrillation With and Without Antiplatelet Therapy

Introduction: Antiplatelet (APT) therapy is challenging in patients on oral anticoagulants (OACs) for nonvalvular atrial fibrillation (NVAF) who have coronary artery diseases (CAD). Analyzing large scale registry of consecutive patients with NVAF should provide further guide for the safety and efficacy of combination therapy. Methods: We conducted historical multicenter registry at 71 centers in Japan between March 2017 and March 2018. The eligibility criteria were patients on OACs for NVAF on February 2013. There were no exclusion criteria and consecutive patients who met the eligibility criteria were registered. All patients were followed until March 2017. Co-primary endpoints were ischemic strokes including transient ischemic attack and hemorrhagic stroke including subarachnoid hemorrhage. The secondary endpoints were all-cause mortality, ischemic events (acute coronary syndrome, ischemic strokes, or systemic embolism), and major bleedings defined by ISTH and TIMI criteria. We estimated HRs of OACs and APT combination relative to OACs alone by Cox proportional hazard model adjusting for clinically relevant confounders. Results: Median age was 74 (range 20-101) years of 7826 registered patients. Sustained NVAF accounted for 49% and 73% of patients had history of CAD. Cumulative incidences of ischemic stroke and hemorrhagic stroke at 4 years were 3.8% and 0.91% in No-APT group while 5.3% and 1.2% in APT group, respectively (Figure). Adjusted HRs (95%CI) of APT group for ischemic stroke and hemorrhagic stroke were 1.03 (0.76-1.40) and 1.27 (0.67-2.4), respectively. Adjusted HRs (95%CI) for all-cause mortality, ischemic events, and major bleedings were 0.98 (0.79-1.23), 0.98 (0.74-1.32), and 1.25 (1.00-1.57), respectively. Conclusions: Adding APT in patients on AOC for NVAF did not decrease ischemic strokes and not increase hemorrhagic strokes. Because combination therapy might increase the risk of major bleedings, OAC alone should be prioritized.

516 WITHDRAWN:Â Non-Vitamin K Anticoagulation for Non-Valvular Atrial Fibrillation in Regional Australia

516 WITHDRAWN:Â Non-Vitamin K Anticoagulation for Non-Valvular Atrial Fibrillation in Regional Australia

Prescribers' perceptions of benefits and limitations of direct acting oral anticoagulants in non-valvular atrial fibrillation.

Background:There is an acknowledged lack of robust and rigorous research focusing on the perspectives of those prescribing direct acting oral anticoagulants (DOACs) for non-valvular atrial fibrillation (AF).Objective:The objective was to describe prescribers’ experiences of using DOACs in the management of non-valvular AF, including perceptions of benefits and limitations.Methods:A cross-sectional survey of prescribers in a remote and rural area of Scotland. Among other items, the questionnaire invited free-text description of positive and negative experiences of DOACs, and benefits and limitations. Responses were independently analysed by two researchers using a summative content analysis approach. This involved counting and comparison, via keywords and content, followed by interpretation and coding of the underlying context into themes.Results:One hundred and fifty-four responses were received, 120 (77.9%) from physicians, 18 (11.7%) from nurse prescribers and 10 (6.4%) from pharmacist prescribers (6 unidentified professions). Not having to monitor INR was the most cited benefit, particularly for prescribers and patients in remote and rural settings, followed by potentially improved patient adherence. These benefits were reflected in respondents’ descriptions of positive experiences and patient feedback. The main limitations were the lack of reversal agents, cost and inability to monitor anticoagulation status. Many described their experiences of adverse effects of DOACs including fatal and non-fatal bleeding, and upper gastrointestinal disturbances.Conclusions:While prescribers have positive experiences and perceive benefits of DOACs, issues such as adverse effects and inability to monitor anticoagulation status merit further monitoring and investigation. These issues are particularly relevant given the trajectory of increased prescribing of DOACs.

Dabigatran etexilate in patients with nonvalvular atrial fibrillation: benefits of application in certain clinical situations

The review discusses the problem of patient-oriented choice of anticoagulants for nonvalvular atrial fibrillation (AF). The efficacy and safety profile of dabigatran etexilate and a group of patients with advantage of dabigatran application: patients with a high risk or history of ischemic stroke, patients who are indicated for combination antithrombotic therapy, and patients with a high risk of emergency surgical interventions and procedures, as well as with a high risk of bleeding, etc. The place of idarucizumab, a direct dabigatran etexilate antagonist, is shown.

P6258Direct oral anticoagulants in non-valvular atrial fibrillation: accuracy of traditional bleeding scores in the elderly

Abstract Background Due to the fear of increased risk of bleeding, anticoagulation treatment is underutilized in the prevention of stroke in elderly patients with non-valvular atrial fibrillation (NVAF). Although direct oral anticoagulants (DOAC) are safer than VKA, still little is known about the risk factors associated with bleeding in elderly patients treated with DOAC. Furthermore, it is still uncertain whether the risk scores that are currently used can serve to effectively identify higher bleeding risk in elderly subjects. Purpose The aim of this study was to identify predictors of bleeding in a cohort of elderly people affected by NVAF treated with DOAC, and to evaluate the accuracy of risk scores for bleeding used at present. Methods Data on outpatients aged ≥75 years, naïve for DOAC therapy, who started therapy with Dabigatran, Rivaroxaban, Apixaban or Edoxaban for the prevention of thromboembolism during FANV were analyzed. HASBLED, ATRIA, OBRI and ORBIT scores were calculated for each patient. Patients had follow-up for 12 months during which deaths, therapy discontinuation and adverse events such as thromboembolism and bleeding were reported. Potential predictors of bleeding and the predictive value of each bleeding score were tested using univariate Cox regression; testing accuracy was evaluated using ROC curves. Results A total of 291 patients (52.9% female, mean age 82.85±5.18 years) had a median follow-up time of 11 (10–12) months. The incidence rate of major bleeding was 4.7 per 100 patient-years, the rate of intracranial bleeding was 0.4 per 100 patient-years. Patients who had major bleeding were more often affected by heart failure (63.6% vs 25%; p=0.009) and thrombocytopenia (36.4% vs 7.4%; p=0,009). However in the multivariate analysis only heart failure remained statistically associated with major bleeding (HR 3.83, 95% CI 1.06–13.85; p=0.041). None of tested bleeding risk scores was able to predict major bleeding in our cohort. HASBLED and ORBIT scores were able to predict major and non-major clinically relevant bleeding (HR 1.32; 95% CI 1.01–1.71; p=0.042 and HR 1.20; 95% CI 1.00- 1.43; p=0.046); only the ORBIT score was found to be statistically significant, but with weak discriminatory power at ROC curves (AUC 0.59; 95% CI 0.51–0.68; p=0.041). Conclusions In our cohort of elderly patients aged 75 or older, anticoagulated for NVAF, heart failure history was the only effective predictor of major bleeding risk during DOAC treatment. None of the bleeding risk scores used currently have demonstrated a good discriminatory power in our cohort. As predictive factors of bleedings in DOAC-treated patients may not be the same as those for VKA-treated patients and those in elderly may also be differ in younger people, it calls for more investigation on the topic.

The Nephrological Aspects of the Use of Rivaroxaban and Other Direct Peroral Anticoagulants in Non-Valvular Atrial Fibrillation

Chronic kidney disease (CKD) is a powerful cardiovascular risk factor, its presence is accompanied by an increased risk of hospitalization for exacerbation of chronic heart failure (CHF), adverse outcomes in myocardial infarction, and cardiovascular mortality. Among the adverse events, an increased risk of atrial fibrillation (AF) should be noted. This article contains discussion of current approaches to the treatment of AF in patients with different stages of CKD, data on benefits of certain direct oral anticoagulants, as well as comparative characteristics of therapy with direct oral anticoagulants and warfarin. Pharmacokinetics and pharmacodynamics of direct oral anticoagulants, which determine the features of therapy in CKD, are also considered.

Elderly Bleeding Risk of Direct Oral Anticoagulants in Nonvalvular Atrial Fibrillation: A Systematic Review and Meta-Analysis of Cohort Studies.

IntroductionThe 2014 American Heart Association (AHA)/American College of Cardiology (ACC)/Heart Rhythm Society (HRS) guidelines recommend anticoagulation to reduce clot formation and the risk of thromboembolic events in patients with atrial fibrillation but does not specify guidelines for the elderly population. Direct oral anticoagulants (DOACs) are newer US FDA-approved alternatives to warfarin and include dabigatran, rivaroxaban, apixaban and edoxaban. The efficacy of DOACs is heavily researched, but few studies have evaluated their bleeding risk.ObjectivesThis systematic review and meta-analysis investigates which DOAC has the lowest bleeding risk in elderly patients with nonvalvular atrial fibrillation (NVAF).MethodsCINAHL and MEDLINE databases were searched using specific keywords, and 244 results were identified and screened. Inclusion criteria required a major bleeding event requiring hospitalization as an outcome and excluded patients with severe renal failure. Articles that met inclusion criteria were assessed for risk of bias using the Cochrane Tool to Assess Risk of Bias in Cohort Studies. Review Manager (version 5) was used to perform the random-effects model meta-analysis. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated. P < 0.05 was considered statistically significant.ResultsSix articles met inclusion criteria and encompassed 446,042 patients in total. Apixaban and dabigatran had statistically significant risk reductions compared with warfarin, whereas rivaroxaban did not (HR 0.60 [95% CI 0.52–0.69], p < 0.00001; HR 0.79 [95% CI 0.70–0.90], p = 0.0005; HR 1.03 [95% CI 0.86–1.22], p = 0.77, respectively.) Data regarding edoxaban were limited and thus not included in the analysis.ConclusionApixaban and dabigatran have a significantly decreased major bleeding risk (40 and 21%, respectively) compared with warfarin. There was no statistical difference in bleeding risk between rivaroxaban and warfarin. Head-to-head prospective randomized controlled trials are required to assess the true bleeding risk of each DOAC.

Review on Future Targets and Current Trends in Transcatheter Left Atrial Appendage Closure

Atrial fibrillation is cause for a growing burden of thromboembolic stroke. Transcatheter left atrial appendage closure is an alternative to lifelong oral anticoagulation for many patients with nonvalvular atrial fibrillation. Reviewed here are three commonly used devices (Watchman, Amplatzer Cardiac Plug/Amulet, and Lariat) and their key clinical trials, special candidate patient populations, and recent investigations of the impact of post-procedure antithrombotic strategies. Transcatheter left atrial appendage closure devices provide noninferior thromboembolic stroke risk reduction and superior bleeding risk reduction compared with oral anticoagulation in nonvalvular atrial fibrillation. Very recent studies of post-procedure antithrombotic regimens describe a variety of anticoagulant and antiplatelet pharmacotherapies without clear impact on device-associated thrombus or post-procedure embolic stroke though more study is needed. Transcatheter left atrial appendage closure is a viable alternative to lifelong oral anticoagulation to decrease thromboembolism and bleeding in patients with nonvalvular atrial fibrillation who are at increased risk of adverse event with anticoagulants. Patient populations at risk of bleeding on anticoagulants have been demonstrated to benefit from this technology, but there are several additional benefits of left atrial appendage closure unrelated to bleeding risks for specific patient populations. Data on the optimal short-term (weeks to months) post-procedure antithrombotic regimens is emerging and will play a significant role in how to best treat patients and which patients will benefit most from left atrial appendage closure.

Comparison between the different new anti-coagulants for non-valvular atrial fibrillation: network meta-analysis

Atrial fibrillation is associated with high risk of ischaemic stroke which is considered a major fatal complication in atrial fibrillation. That’s why, anticoagulants were used to prevent this major complication. However, anticoagulants themselves are associated with their own complications. A systematic search of Embase, Medline and Google scholar were conducted. The included papers were extracted for outcomes related to the complications of each drugs. A Bayesian network meta-analysis based on Markov chain Monte Carlo simulation (MCMC) with 10000 burn-in iterations and 50000 inference iterations. We found eighteen papers that fit our inclusion criteria. Apixaban had the least risk of major bleeding compared to Warfarin [HR = 0.536, 95% (0.448, 0.652)] and the least risk of gastrointestinal hemorrhage. For stroke risk, the Rivaroxaban had the least risk compared to Warfarin [HR = 1.05, 95% (0.98, 1.14)]. For intracranial hemorrhage, dabigatran had the least risk of intracranial haemorrhage compared to Warfarin [HR = 0.46, 95% CrI (0.36, 0.61)]. For the thromboembolism risk, other non-vitamin k antagonist had the least risk of intracranial haemorrhage compared to Warfarin [HR = 0.523, 95% (0.095, 2.85)]. There were no conclusive results about the best anticoagulant drugs for non-valvular atrial fibrillation. Apixaban was the least among them to be associated with major bleeding, while rivaroxaban was ranked the first with least stroke complications. Furthermore, dabigatran was associated with less risk of intracranial haemorrhage compared to other anticoagulants.

Comparative Stroke, Bleeding, and Mortality Risks in Older Medicare Patients Treated with Oral Anticoagulants for Nonvalvular Atrial Fibrillation

BackgroundNonvitamin K antagonist oral anticoagulants (NOACs) are alternatives to warfarin in patients with nonvalvular atrial fibrillation. Randomized trials compared NOACs with warfarin, but none have compared individual NOACs against each other for safety and effectiveness. MethodsWe performed a retrospective new-user cohort study of patients with nonvalvular atrial fibrillation enrolled in US Medicare who initiated warfarin (n = 183,318), or a standard dose of dabigatran (150 mg twice daily; n = 86,198), rivaroxaban (20 mg once daily; n = 106,389), or apixaban (5 mg twice daily; n = 73,039) between October 2010 and September 2015. Propensity score-adjusted Cox proportional hazards regression was used to estimate adjusted hazard ratios (HR) and 95% confidence intervals (CI) for the outcomes of thromboembolic stroke, intracranial hemorrhage, major extracranial bleeding, and all-cause mortality, comparing each NOAC with warfarin, and with each other NOAC. ResultsCompared with warfarin, each NOAC was associated with reduced risks of thromboembolic stroke (20%-29% reduction; P = .002 [dabigatran], P < 0.001 [rivaroxaban, apixaban]), intracranial hemorrhage (35%-62% reduction; P < 0.001 [each NOAC]), and mortality (19%-34% reduction; P < .001 [each NOAC]). The NOACs were similar for thromboembolic stroke but rivaroxaban was associated with increased risks of intracranial hemorrhage (vs dabigatran: HR = 1.71; 95% CI, 1.35-2.17), major extracranial bleeding (vs dabigatran: HR = 1.32; 95% CI, 1.21-1.45; vs apixaban: HR = 2.70; 95% CI, 2.38-3.05), and death (vs dabigatran: HR = 1.12; 95% CI, 1.01-1.24; vs apixaban: HR = 1.23; 95% CI, 1.09-1.38). Dabigatran was associated with reduced risk of intracranial hemorrhage (HR = 0.70; 95% CI ,0.53-0.94) and increased risk of major extracranial bleeding (HR = 2.04; 95% CI, 1.78-2.32) compared with apixaban. ConclusionsAmong patients treated with standard-dose NOAC for nonvalvular atrial fibrillation and warfarin users with similar baseline characteristics, dabigatran, rivaroxaban, and apixaban were associated with a more favorable benefit–harm profile than warfarin. Among NOAC users, dabigatran and apixaban were associated with a more favorable benefit–harm profile than rivaroxaban.

Utilization of Anticoagulants in Nonvalvular Atrial Fibrillation Before and After Catheter Ablation at Shanghai, China.

Both vitamin K antagonists (VKAs) and novel oral anticoagulants (NOACs) are effective for stroke prevention in nonvalvular atrial fibrillation (NVAF) patients. This study evaluated the utilization of VKA and NOACs in NVAF patients before and after catheter ablation in China. Prescription data were retrospectively collected between January 1, 2016, and December 31, 2016, including indication of use, dose, renal function, and risk assessment (CHA2DS2-VASc score and HAS-BLED score) in Zhongshan Hospital of Fudan University. Trends and factors associated with anticoagulants use before and after ablation were evaluated. A total of 475 patients with NVAF who received ablation were included in the analysis. Of all, 53.26% of them received antithrombotic therapy preablation. Warfarin was prescribed in 35.26%, with NOACs in 11.37%. Four hundred seventy-three patients received antithrombotic therapy (99.58%) postablation, 236 patients with NOACs (49.68%). CHA2DS2-VASc score, HAS-BLED score, hypertension, diabetes mellitus, and alcohol were independently associated with anticoagulant utilization before catheter ablation. The higher CHA2DS2-VASc score was associated with less frequent prescription of NOACs postablation. The preablation anticoagulation use was still inadequate in China, and CHA2DS2-VASc score was a significant factor influencing the preablation anticoagulant utilization. The utilization rate of NOACs increased significantly postablation, especially for dabigatran, which implied that more physicians prefer to prescribe NOACs for NVAF patients after ablation in our country and may be attributed to the aspects such as ease of NOAC use but also possibly the greater safety and efficacy. Furthermore, the physicians may reluctant to use NOACs for high stroke risk atrial fibrillation patients after catheter ablation.