Appropriateness of Direct Oral Anticoagulant Dosing in Patients With Atrial Fibrillation: Insights From the Veterans Health Administration.

BACKGROUND: Direct oral anticoagulants (DOACs) have strict dosing guidelines, but recent studies indicate that inappropriate dosing is common, particularly in chronic kidney disease (CKD), for which it has been reported to be as high as 43%. Since 2011, the Veterans Health Administration (VA) has implemented anticoagulation management programs for DOACs, generally led by pharmacists, which has previously been shown to improve medication adherence. OBJECTIVE: We investigated the prevalence of overdosing and underdosing of DOACs in the VA. METHODS: Using data from the TREAT-AF cohort study (The Retrospective Evaluation and Assessment of Therapies in AF), we identified VA patients with newly diagnosed atrial fibrillation (AF) and receipt of a DOAC between 2003 and 2015. We classified dosing as correct, overdosed, or underdosed based on the Food and Drug Administration-approved dosing criteria. RESULTS: Of 230 762 patients, 5060 received dabigatran (77.3%) or rivaroxaban (22.7%) within 90 days of AF diagnosis (age 69 [10[ years; CHA2DS2-VASc 1.6 [1.4]), of which 1312 (25.9%) had CKD based on estimated glomerular filtration rate <60. Overall, 93.6% of patients, 83.2% with CKD, received appropriate DOAC dosing. Incorrect dosing increased with worsening renal function. CONCLUSION: Compared to recent studies of commercial payers and health-care systems, incorrect dosing of DOACs is less common across the VA. Pharmacist-led DOAC management or similar anticoagulation management interventions may reduce the risk of incorrect dosing across health-care systems.

Site Variation and Outcomes for Antithrombotic Therapy in Atrial Fibrillation Patients After Percutaneous Coronary Intervention.

BACKGROUND: Patients with atrial fibrillation (AF) treated with percutaneous coronary intervention (PCI) require multiple antithrombotic therapies. The optimal strategy is debated suggesting increased treatment variation. This study sought to characterize site-level variation in antithrombotic therapies in AF patients after PCI and determine the association with outcomes. METHODS: Using the retrospective TREAT-AF study (The Retrospective Evaluation and Assessment of Therapies in AF) from the Veterans Health Administration, patients with newly diagnosed, nonvalvular AF between 2004 and 2015 followed by a PCI with a P2Y12-antagonist prescription were identified. Patients were grouped according to the therapy dispensed 7 days before until 30 days after the PCI: oral anticoagulation plus platelet inhibition (OAC+PI) or platelet inhibition only. A combined outcome of death, myocardial infarction, stroke, or major bleeding was assessed 1 year after PCI and Cox regression was performed to estimate hazard ratios. RESULTS: Of 230 762 patients with newly diagnosed AF, 4042 (1.8%) underwent PCI and received a P2Y12-antagonist during the observation period (age, 67±9 years; CHA2DS2-VASc, 2.7±1.7; HAS-BLED, 2.6±1.2). Among these, 47% were prescribed OAC+PI, and 53% platelet inhibition only 7 days before until 30 days after the PCI. Across 63 sites, the use of OAC+PI ranged from 19% to 66%. Prescription of OAC+PI was independently associated with a reduction in the combined outcome of death, myocardial infarction, stroke, or major bleeding compared with platelet inhibition only (adjusted hazard ratio, 0.85; 95% CI, 0.73-0.99; P=0.033). CONCLUSIONS: In patients with established AF undergoing PCI, the use of OAC+PI varied substantially across sites in the 30 days post-PCI. Anticoagulation appeared to be underutilized but was associated with improved outcomes. Strategies to promote OAC+PI and minimize site variation may be useful, particularly in light of recent randomized trials.

Secular trends in success rate of catheter ablation for atrial fibrillation: The SMASH-AF cohort.

BACKGROUND: Approaches, tools, and technologies for atrial fibrillation (AF) ablation have evolved significantly since its inception. We sought to characterize secular trends in AF ablation success rates. METHODS: We performed a systematic review and meta-analysis of AF ablation from January 1, 1990, to August 1, 2016, searching PubMed, Scopus, and Cochrane databases. Major exclusion criteria were insufficient outcome reporting and ablation strategies that were not prespecified and uniform. We stratified treatment arms by AF type (paroxysmal AF; nonparoxysmal AF) and analyzed single-procedure outcomes. Multivariate meta-regressions analyzed effects of study, patient, and procedure characteristics on success rate trends. Registered in PROSPERO (CRD42016036549). RESULTS: A total of 180 trials and observational studies with 28,118 patients met inclusion. For paroxysmal AF ablation studies, unadjusted success rate summary estimates ranged from 73.1% in 2003 to 77.1% in 2016, increasing by 0.9%/year (95% CI 0.4%-1.4%; P = .001; I2 = 90%). After controlling for study design and patient demographics, rate of improvement in success rate summary estimate increased (1.6%/year; 95% CI 0.9%-2.2%; P = .001; I2 = 87%). For nonparoxysmal AF ablation studies, unadjusted success rate summary estimates ranged from 70.0% in 2010 to 64.3% in 2016 (1.1%/year; 95% CI -1.3% to 3.5%; P = .37; I2 = 85%), with no improvement in multivariate analyses. CONCLUSIONS: Despite substantial research investment and health care expenditure, improvements in AF ablation success rates have been incremental. Meaningful improvements may require major paradigm or technology changes, and evaluation of clinical outcomes such as mortality and quality of life may prove to be important going forward.

Efficacy of Ablation Lesion Sets in Addition to Pulmonary Vein Isolation for Paroxysmal Atrial Fibrillation: Findings From the SMASH - AF Meta-Analysis Study Cohort.

Background The objective was to explore the efficacy of ablation lesion sets in addition to pulmonary vein isolation ( PVI ) for paroxysmal atrial fibrillation. The optimal strategy for catheter ablation of paroxysmal atrial fibrillation is debated. Methods and Results The SMASH-AF (Systematic Review and Meta-analysis of Ablation Strategy Heterogeneity in Atrial Fibrillation) study cohort includes trials and observational studies identified in PubMed, Scopus, and Cochrane databases from January 1 1990, to August 1, 2016. We included studies reporting single procedure paroxysmal atrial fibrillation ablation success rates. Exclusion criteria included insufficient reporting of outcomes, ablation strategies that were not prespecified and uniform, and a sample size of fewer than 40 patients. We analyzed lesion sets performed in addition to PVI ( PVI plus) using multivariable random-effects meta-regression to control for patient, study, and procedure characteristics. The analysis included 145 total studies with 23 263 patients ( PVI- only cohort: 115 studies, 148 treatment arms, 16 500 patients; PVI plus cohort: 39 studies; 46 treatment arms, 6763 patients). PVI plus studies, as compared with PVI -only studies, included younger patients (56.7 years versus 58.8 years, P=0.001), fewer women (27.2% versus 32.0% women, P=0.002), and were more methodologically rigorous with longer follow-up (29.5 versus 17.1 months, P 0.004) and more randomization (19.4% versus 11.8%, P<0.001). In multivariable meta-regression, PVI plus studies were associated with improved success (7.6% absolute improvement [95% CI, 2.6-12.5%]; P<0.01, I2=88%), specifically superior vena cava isolation (4 studies, 4 treatment arms, 1392 patients; 15.1% absolute improvement [95% CI, 2.3-27.9%]; P 0.02, I2=87%). However, residual heterogeneity was large. Conclusions Across the paroxysmal atrial fibrillation ablation literature, PVI plus ablation strategies were associated with incremental improvements in success rate. However, large residual heterogeneity complicates evidence synthesis.

Geographic and racial representation and reported success rates of studies of catheter ablation for atrial fibrillation: Findings from the SMASH-AF meta-analysis study cohort.

INTRODUCTION: We performed a systematic review and meta-analysis of geographic and racial representation and reported success rates of studies of catheter ablation for atrial fibrillation (AF). METHODS AND RESULTS: We searched PubMed, Scopus, and Cochrane databases from 1/1/1990 to 8/1/2016 for trials and observational studies reporting AF ablation outcomes. Major exclusion criteria were insufficient reporting of outcomes, non-English language articles, and ablation strategies that were not prespecified and uniform. We described geographic and racial representation and single-procedure ablation success rates by country, controlling for patient demographics and study design characteristics. The analysis cohort included 306 studies (49,227 patients) from 28 countries. Over half of the paroxysmal (PAF) and nonparoxysmal AF (NPAF) treatment arms were conducted in 5 and 3 countries, respectively. Reporting of race or ethnicity demographics and outcomes were rare (1 study, 0.3%) and nonexistent, respectively. Unadjusted success rates by country ranged from 63.5% to 83.0% for PAF studies and 52.7% to 71.6% for NPAF studies, with substantial variation in patient demographics and study design. After controlling for covariates, South Korea and the United States had higher PAF ablation success rates, with large residual heterogeneity. NPAF ablation success rates were statistically similar by country. CONCLUSIONS: Studies of AF ablation have substantial variation in patient demographics, study design, and reported outcomes by country. There is limited geographic representation of trials and observational studies of AF ablation and a paucity of race- or ethnicity-stratified results. Future AF ablation studies and registries should aim to have broad representation by race, geography, and ethnicity to ensure generalizability.

Safety and Efficacy of Rivaroxaban in Patients With Cardiac Implantable Electronic Devices: Observations From the ROCKET AF Trial.

BACKGROUND: Although implantation of cardiac implantable electronic devices (CIEDs) in patients receiving warfarin is well studied, limited data are available on the use of oral factor Xa inhibitors in this setting. METHODS AND RESULTS: Using data from Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF) (n=14 264), we compared baseline characteristics and clinical outcomes in patients with atrial fibrillation randomized to rivaroxaban versus warfarin who did and did not undergo CIED implantation or revision. In this post-hoc, postrandomization, on-treatment analysis, only the first intervention per patient was analyzed. During a median follow-up of 2.2 years, 453 patients (242 rivaroxaban group; 211 warfarin group) underwent de novo CIED implantation (64.2%) or revision procedures (35.8%). Patients who received CIEDs were older, more likely to be male, and more likely to have past myocardial infarction, but had similar stroke risk compared to patients who did not receive CIEDs. Most patients who received a device had study drug interrupted for the procedure and did not receive bridging anticoagulation. During the 30-day postprocedural period, 11 patients (4.55%) in the rivaroxaban group experienced bleeding complications compared with 15 (7.13%) in the warfarin group. Thromboembolic complications occurred in 3 patients (1.26%) in the rivaroxaban group and 1 (0.48%) in the warfarin group. Event rates were too low for formal hypothesis testing. CONCLUSIONS: Bleeding and thromboembolic events were low in both rivaroxaban- and warfarin-treated patients. Periprocedural use of oral factor Xa inhibitors in CIED implantation requires further study in prospective, randomized trials. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00403767.