Safety of direct oral anticoagulants in real-world clinical practice: translating the trials to everyday clinical management

Apixaban, edoxaban and rivaroxaban but not dabigatran are associated with higher mortality compared to vitamin-K antagonists: A retrospective German claims data analysis

BACKGROUND

Vitamin-K antagonists (VKAs) have widely been replaced by non-VKA oral anticoagulants (NOACs). This includes Austria, Germany and Switzerland, where as VKA, instead of warfarin, the much longer-acting phenprocoumon is used, which was not compared to NOACs in clinical trials.

METHODS

Using administrative data from a large German health insurance, we included all anticoagulation-naïve patients with a first prescription of a NOAC or VKA between 2012 and 2020. We analysed overall survival, major adverse cardiac and cerebrovascular events, major thromboembolic events and major bleeding.

RESULTS

Overall, 570,137 patients were included (apixaban: 26.9%, dabigatran: 4.6%, edoxaban: 8.8%, rivaroxaban: 39.1% and VKA: 20.7% of these 99.4% phenprocoumon). In the primary analysis using a 1:1 propensity score matching-cohort (PSM-cohort), a significantly higher overall mortality was found for apixaban, edoxaban and rivaroxaban (all p < 0.001) but not for dabigatran (p = 0.13) compared to VKA. In this PSM-cohort, 5-year mortality was 22.7% for apixaban versus 12.7% for VKA, 19.5% for edoxaban versus 11.4% for VKA, 16.0% for rivaroxaban versus 12.3% for VKA (all p < 0.001) and 13.0% for dabigatran versus 12.8% for VKA (p = 0.06). The observed effect was confirmed in sensitivity analyses using un-weighted and three different weighted Fine-Gray regression models on the basis of the entire cohort.

CONCLUSIONS

In this large real-world analysis, apixaban, edoxaban and rivaroxaban, but not dabigatran, were associated with worse survival compared to VKA. These findings, consistent with a few other studies including phenprocoumon, cast profound doubts on the unreflected, general use of NOACs. Randomized trials should assess whether phenprocoumon might actually be superior to NOACs.

Exploring bleeding in oral anticoagulant users: assessing incidence by indications and risk factors in the entire nationwide cohort

Background

Oral anticoagulants (OACs) are essential for the prevention and treatment of thromboembolic disorders, but bleeding, a major complication, can have a fatal impact on the patient's treatment.

Objectives

We aimed to estimate the nationwide, real-world incidence rate of bleeding in patients taking OACs and confirm the incidence by indications and risk factors.

Methods

This cross-sectional study identified OAC users from April 1 to December 31, in both 2019 and 2020, using the HIRA-NPS database. The primary outcome variables were the incidence rate of major bleeding events during OAC treatment and within 30 days of treatment discontinuation. We estimated the adjusted incidence rate ratio (aIRR) in subpopulations.

Results

Among 18,822 OAC users, the incidence rate of major bleeding was 27.9 (95% CI: 24.6-31.5) per 1,000 person-years. The incidence rate of major bleeding was higher in patients with a bleeding history, with an aIRR of 11.51; those at high bleeding risk (HAS-BLED score ≥3), with an aIRR of 1.51; those with high CCI scores ≥3, with an aIRR of 1.88; and those with liver disease, with an aIRR of 1.41. For indications, compared to patients with nonvalvular atrial fibrillation (NVAF), the aIRR of major bleeding was significantly higher at an aIRR of 2.35 in patients undergoing VTE treatment. Patients with ischemic stroke showed a higher incidence of major bleeding with an aIRR of 2.13 than NVAF patients. The aIRR of major bleeding in the oral anticoagulant group, compared to the matched control group, was 2.25 (95% CI: 1.93-2.63).

Conclusion

These findings may be useful for implementing strategies to improve the evaluation and management of anticoagulation-related bleeding.

Edoxaban treatment in a post-infarction experimental model

BACKGROUND

The sequelae of myocardial infarction (MI) require specific pharmacological therapy to minimise the post-MI remodelling, which in many cases evolves into cardiovascular complications. The aim of this study was to analyse the effect of edoxaban, an oral anticoagulant, on cardiac recovery in a rat model of permanent coronary artery ligation.

METHODS

An experimental method to assess the post-MI remodelling in rats for 4 weeks, based on cardiac magnetic resonance imaging (MRI) and final histological analysis of the hearts was performed. The influence of daily oral treatment with edoxaban (20 mg/kg/day) for 28 days post-MI was analysed in comparison to vehicle.

RESULTS

In our model, edoxaban was shown to be safe and bleeding was observed in 1 of 10 animals. General physical recovery of the treated animals was shown by higher body weight recovery compared with non-treated animals (38.6 ± 2.9 vs. 29.9 ± 3.1 g, respectively, after 28 days). There was not a pronounced effect of edoxaban in post-MI cardiac remodelling, but mitigated fibrosis was observed by the reduced expression of vascular endothelial growth factor and tumour growth factor β1 in the peri-infarct zone.

CONCLUSIONS

Our analysis provided the experimental basis to support the feasibility of MRI to study cardiac function and characterise myocardial scarring in a rat model. Overall data suggested the safety of edoxaban in the model, and compared to placebo, it showed a better post-MI recovery, probably by reducing fibrosis of the heart. Further research on mid-term cardiac recovery with edoxaban after MI is justified.

Potentially Inappropriate Drug Duplication in a Cohort of Older Adults with Dementia

BACKGROUND

Concurrent use of 2 nonsteroidal anti-inflammatory drugs, selective serotonin reuptake inhibitors, loop diuretics, angiotensin-converting enzyme inhibitors, or anticoagulants is considered potentially inappropriate by Screening Tool of Older Persons' Prescriptions and Screening Tool to Alert to Right Treatment criteria.

OBJECTIVE

The objective was to examine drug duplication in a cohort of older adults with dementia.

METHODS

Cohort entry for Nova Scotia Seniors' Pharmacare Program beneficiaries was the date an International Classification of Diseases ninth edition or 10th edition code for dementia was recorded in accessed databases between March 1, 2005, and March 31, 2015. Medication dispensation and sociodemographic data were captured from the Nova Scotia Seniors' Pharmacare Program database between April 1, 2010, and March 31, 2015. Duplication was considered when 2 drugs from the same class were dispensed such that the supply in the patient's possession could overlap for more than 30 days. We reported number of cases of duplication and duration of overlap. Sex differences in drug duplication were assessed with bivariate logistic regression.

RESULTS

In the cohort of 28,953 Nova Scotia Seniors' Pharmacare Program beneficiaries with dementia, we documented concurrent use in 101 (1.7%) nonsteroidal anti-inflammatory drugs users (mean duration = 75.6 days), 95 (1.0%) selective serotonin reuptake inhibitors users (mean duration = 146.6 days), 5 (0.07%) loop diuretic users (mean duration = 530.6 days), 183 (2.0%) angiotensin-converting enzyme inhibitor users (mean duration = 123.9 days), and 160 (3.5%) anticoagulant users (mean duration = 63.6 days). Nonsteroidal anti-inflammatory drug pairs were most commonly celecoxib with naproxen or diclofenac. Selective serotonin reuptake inhibitors duplication was most commonly sertraline with citalopram. No sex differences in risk for drug duplication were identified.

CONCLUSIONS

Drug duplication was identified in a cohort of older adults with dementia and is a feasible target for intervention. (Curr Ther Res Clin Exp. 2021; 82:XXX-XXX).

Changes of recommended anticoagulation therapy in patients with atrial fibrillation and high thrombotic risk: long-term follow-up data from two hospital centers

Aim : To investigate changes of anticoagulation therapy in patients with atrial fibrillation (AF) and high thrombotic risk.Methods : We retrospectively analyzed 1061 patients with non-valvular AF and indication for anticoagulation therapy referred in a period from 2013 to 2018 and followed-up for a median time of 38 months.Results : Therapy change occurred in 206 (19.5%) patients (195 switches and 11 permanent discontinuations). Only 37% of patients on warfarin had optimal dosing and their duration of therapy was significantly shorter compared to direct oral anticoagulants (DOACs; (adjusted HR 1.21, 95% CI 1.09-1.37). Therapy change occurred in only 33% of patients with poorly controlled warfarin, and in only 24% of patients that experienced a thrombotic event while taking warfarin. Optimal dosing was an independent factor for any therapy change during follow-up, irrespective of type of anticoagulant drug at baseline. DOAC swapping occurred in 39% of all DOAC to DOAC switches, with one bleeding event and no thrombotic events documented after a DOAC swap.Conclusion : High risk patients with AF rarely discontinue anticoagulation therapy. The need for therapy change should be emphasized in patients with non-optimal dosing, and in patients that experience thrombotic events while taking warfarin.

Efficacy and safety of non-vitamin K antagonist oral anticoagulants for venous thromboembolism: a meta-analysis

Objective

Several trials had compared the efficacy and safety between non-vitamin K antagonist oral anticoagulants and warfarin for acute venous thromboembolism, but the results were incomplete. This updated review comprehensively assessed the efficacy and safety of non-vitamin K antagonist oral anticoagulants for venous thromboembolism.

Design

Meta-analysis of randomised control trials. Six databases were searched from January 2000 to December 2018.

Setting

Adult patients had got non-vitamin K antagonist oral anticoagulants or warfarin for venous thromboembolism.

Participants

Randomised control trials that compared the efficacy and safety between non-vitamin K antagonist oral anticoagulants and warfarin.

Main outcome measures

The efficacy and safety of non-vitamin K antagonist oral anticoagulants .

Results

Seven studies involving 29,879 cases were included, among which 14,943 cases were assigned to non-vitamin K antagonist oral anticoagulants group and 14,936 cases to warfarin group. Meta-analysis showed that compared with warfarin, recurrent venous thromboembolism (odds ratio 0.94 [95% confidence interval 0.81 to 1.11]), death related to venous thromboembolism or fatal pulmonary embolism (odds ratio 1.00 [95% confidence interval 0.63 to 1.60]), symptomatic deep-vein thrombosis (odds ratio 0.88 [95% confidence interval 0.72 to 1.09]), symptomatic nonfatal pulmonary embolism (odds ratio 1.03 [(95% confidence interval 0.82 to 1.30]) and all deaths (odds ratio 0.92 [95% confidence interval 0.76 to 1.12]) are similar in non-vitamin K antagonist oral anticoagulants group, but major bleeding event (odds ratio 0.61 [95% confidence interval 0.50 to 0.75]) and clinically relevant non-major bleeding event (odds ratio [95% confidence interval 0.53 to 0.85]) are less in non-vitamin K antagonist oral anticoagulants group. .

Conclusions

For the treatment of venous thromboembolism, non-vitamin K antagonist oral anticoagulants is as effective as warfarin, and has a better safety profile than warfarin.

The pleiotropic effects of antithrombotic drugs in the metabolic-cardiovascular-neurodegenerative disease continuum: impact beyond reduced clotting

Antithrombotic drugs are widely used for primary and secondary prevention, as well as treatment of many cardiovascular disorders. Over the past few decades, major advances in the pharmacology of these agents have been made with the introduction of new drug classes as novel therapeutic options. Accumulating evidence indicates that the beneficial outcomes of some of these antithrombotic agents are not solely related to their ability to reduce thrombosis. Here, we review the evidence supporting established and potential pleiotropic effects of four novel classes of antithrombotic drugs, adenosine diphosphate (ADP) P2Y12-receptor antagonists, Glycoprotein IIb/IIIa receptor Inhibitors, and Direct Oral Anticoagulants (DOACs), which include Direct Factor Xa (FXa) and Direct Thrombin Inhibitors. Specifically, we discuss the molecular evidence supporting such pleiotropic effects in the context of cardiovascular disease (CVD) including endothelial dysfunction (ED), atherosclerosis, cardiac injury, stroke, and arrhythmia. Importantly, we highlight the role of DOACs in mitigating metabolic dysfunction-associated cardiovascular derangements. We also postulate that DOACs modulate perivascular adipose tissue inflammation and thus, may reverse cardiovascular dysfunction early in the course of the metabolic syndrome. In this regard, we argue that some antithrombotic agents can reverse the neurovascular damage in Alzheimer's and Parkinson's brain and following traumatic brain injury (TBI). Overall, we attempt to provide an up-to-date comprehensive review of the less-recognized, beneficial molecular aspects of antithrombotic therapy beyond reduced thrombus formation. We also make a solid argument for the need of further mechanistic analysis of the pleiotropic effects of antithrombotic drugs in the future.

Real-world safety and efficacy of direct oral anticoagulants in atrial fibrillation: a systematic review and meta-analysis of 605 771 patients

AIMS

To analyse the safety and efficacy of direct oral anticoagulants (DOACs) in real-world studies including atrial fibrillation (AF) patients.

METHODS AND RESULTS

Systematic review and meta-analysis of observational studies including AF patients on DOACs. Primary endpoints: any, major, gastrointestinal (GI), intracranial haemorrhage (ICH), and haemorrhagic stroke (HS). Secondary endpoints: ischaemic stroke (IS), systemic embolism (SE), myocardial infarction (MI), and all-cause of death. A set of pair-wise meta-analyses using a random effect model and a random effect network meta-analysis under a Bayesian framework were performed. Prospero registration number: CRD42019137111. We included 21 studies with 605 771 AF patients. Apixaban was associated with lower major and GI bleeding compared with Rivaroxaban [hazard ratio (HR) 2.0, 95% confidence interval (CI) 1.6-2.5] and Dabigatran (HR 1.6, 95% CI 1.3-2.1). The latter drug performed better than Rivaroxaban (HR 1.2, 95% CI 1.0-1.5). Dabigatran and Apixaban had a similar association with HS, but Apixaban performed better than Rivaroxaban (HR 1.8, 95% CI 1.1-3.0). Apixaban had a similar association with Rivaroxaban and Dabigatran for ICH, the latter drug performing better than Rivaroxaban (HR 1.3, 95% CI 1.0-1.7). Rankograms showed that Apixaban was likely to be the first-choice treatment in relation to any (65%) major (100%) and GI bleeding (100%) followed by Dabigatran (46%, 100%, 99%, respectively). Dabigatran and Apixaban had similar rank as first choice for ICH (44% and 55%) and HS (52% and 48%). DOACs showed similar association with IS/SE, MI, all-cause of death.

CONCLUSIONS

Analysis of real-world studies shows significant differences for safety among DOACs.

Non-vitamin K antagonist oral anticoagulants for stroke prevention in atrial fibrillation: safety issues in the elderly

INTRODUCTION

Non-vitamin K antagonist oral anticoagulants (NOACs) are increasingly used for stroke prevention in patients with atrial fibrillation (AF). Since NOACs are predominantly used in the elderly with AF at high risk for stroke and bleeding and with comorbidities requiring polypharmacy, it is important to assess their safety and efficacy in this population.

AREAS COVERED

We review changes in pharmacokinetics and pharmacodynamics observed with senescence and the effect on NOACs and drug and food interactions. We also provide an update on challenges related to NOAC use in situations that increases the risk for bleeding or require temporary discontinuation and address practical issues in the elderly AF patients managed on NOACs. Clinical studies and trials with cardiovascular outcomes reported from January 1990 to August 2020 were identified through the Medline database using PubMed, Cochrane Library, and EMBASE database.

EXPERT OPINION

NOACs are highly effective in preventing stroke in AF patients with non-inferior or superior efficacy to warfarin, with reduced risk of major bleeding. However, in the older-elderly, evidence comes mainly from observational studies or extrapolation from studies in populations with minimal functional limitations or comorbidities. The high upfront cost and out-of-pocket expense for copayment or deductibles also limit the use of this effective therapy in a substantial number of patients. The cost reduction may further improve long-term use for NOACs in stroke prevention in elderly patients with AF.

The role of non-vitamin K antagonist oral anticoagulants in Asian patients with atrial fibrillation: A PRISMA-compliant article

BACKGROUND

Given the huge burden of atrial fibrillation (AF) and AF-related stroke in Asia, stroke prevention represents an urgent issue in this region. We herein performed a network meta-analysis to examine the role of non-vitamin K antagonist oral anticoagulants (NOACs) in Asian patients with AF.

METHODS

A systematic search of the publications was conducted in PubMed and Embase databases for eligible studies until July 2019. The odds ratios (ORs) and 95% confidence intervals (CIs) were regarded as the effect estimates. The surface under the cumulative ranking area (SUCRA) for the ranking probabilities was calculated.

RESULTS

A total of 17 studies were included. For comparisons of NOACs vs warfarin, dabigatran (OR = 0.77, 95% CI 0.68-0.86), rivaroxaban (OR = 0.72, 95% CI 0.65-0.81), apixaban (OR = 0.56, 95% CI 0.49-0.65), but not edoxaban reduced the risk of stroke or systemic embolism, wheres dabigatran (OR = 0.56, 95% CI 0.41-0.76), rivaroxaban (OR = 0.66, 95% CI 0.50-0.86), apixaban (OR = 0.49, 95% CI 0.36-0.66), and edoxaban (OR = 0.34, 95% CI 0.24-0.49) decreased the risk of major bleeding. In reducing the risk of stroke or systemic embolism, apixaban and rivaroxaban ranked the best and second best (SUCRA 0.2% and 31.4%, respectively), followed by dabigatran (50.2%), edoxaban (75.2%), and warfarin (93.0%). In reducing the risk of major bleeding, edoxaban, and apixaban ranked the best and second best (1.5% and 30.8%, respectively), followed by dabigatran (48.4%), rivaroxaban (69.2%), and warfarin (100%).

CONCLUSION

NOACs were at least as effective as warfarin, but more safer in Asians with AF. Apixaban was superior to other NOACs for reducing stroke or systemic embolism, while edoxaban showed a better safety profile than other NOACs.

Edoxaban's contribution to key endothelial cell functions

BACKGROUND

We aimed to study the effects of the new oral anticoagulant edoxaban, a factor X activated (FXa) inhibitor, on key endothelial functions that could contribute to cardiovascular benefit.

METHODS

Human umbilical endothelial cells (HUVEC) were obtained from donated umbilical cords and used to analyse 1) structural functions like cell proliferation, migration, and angiogenesis in appropriate assays; 2) anti-inflammatory reactions as mononuclear cell (PBMC) or platelet adhesion to HUVEC monolayers; and 3) haemostasis control by fibrin formation or plasminogen activator modulation. Key molecular effectors and signalling pathways on each function were explored by profiled protein arrays, mRNA, or protein expression analyses.

RESULTS

Edoxaban promoted viability and growth in HUVEC cultures, as well as counteracted the promigratory and antiangiogenic effects of FXa, through action on the PI3K/AKT pathway. Edoxaban inhibited the adhesion to endothelial cells and the transmigration through endothelial monolayers of PBMC, and even counteracted the action of pro-inflammatory stimuli such as FXa by blocking the FXa-induced expression of cell adhesion molecules via the PAR 1-2/PI3K/NF-kB pathway. Haemostatic control of edoxaban could be exerted from the endothelium by the reduction of platelets' adhesion to endothelial cells and the possible acute activation of urokinase plasminogen activator.

CONCLUSIONS

Edoxaban is a safe and structural stabilizing factor for endothelial cells and also has remarkable anti-inflammatory action, preventing PBMC adhesion and transmigration through the endothelium. It may also contribute to haemostasis control by reducing platelet adhesion. Its main molecular mechanism seems to be the control of the PI3K/NF-κB pathways.

Patients' perceptions with dabigatran in patients with atrial fibrillation previously treated with vitamin K antagonists

Aim: To analyze the perception of anticoagulation with dabigatran in patients with nonvalvular atrial fibrillation previously treated with vitamin K antagonists over a 6-month period. Materials & methods: This is a prospective, noninterventional, noncontrolled, multicenter study. To assess patients' perceptions, PACT-Q2 questionnaire was completed. Results: Six hundred and fifty nine patients (73.1 ± 9.4 years, CHA₂DS₂-VASc 3.6 ± 1.6) were included. At baseline, the convenience and satisfaction scores were 60.9 ± 24.9 and 49.9 ± 17.7, respectively. The scores significantly increased along the study. Convenience score was higher in males and in patients with low-moderate thromboembolic risk. Satisfaction score was higher in females. Only 8.0% of patients discontinued dabigatran (3.7% due to side effects). Conclusion: Convenience and satisfaction scores for nonvalvular atrial fibrillation patients treated with dabigatran at 6 months were significantly better than with previous vitamin K antagonists.

New Prospects of Cytoprotection in the Treatment and Prevention of Gastric and Intestinal Diseases (Resolution of an Expert Council and Literature Review)

Aim. To generalize up-to-date information on the possibilities of cytoprotection in the treatment and prevention of gastric and intestinal diseases, as well as to present the materials of an Expert Council meeting held on February 8, 2020 in Moscow under the support of the Alium company.

General provisions. The conducted Expert Council meeting was aimed at discussing the importance of improving the cytoprotective properties of the gastric and intestinal mucous membrane in the treatment of its lesions. It was shown that Rebamipide exhibits positive effects on various parts of the protective barrier of the gastrointestinal tract (GIT), primarily due to its stimulating action on the production of prostaglandins playing a key role in maintaining the cytoprotective properties of the gastrointestinal mucosa. The possibilities of applying Rebamipide for the treatment and prevention of erosive and ulcerative gastrointestinal lesions caused by non-steroidal anti-inflammatory (NSAIDs) and antithrombotic drugs were demonstrated. In the treatment of gastroesophageal reflux disease, Rebamipide is recommended for patients refractory to therapy with proton pump inhibitors (PPIs) and for those with non-acid reflux. The efficacy of Rebamipide in the treatment of Helicobacter pylori (H. pylori) infection, as well as functional dyspepsia and chronic gastritis, was confirmed.

Conclusions. Rebamipid is a highly effective drug positively affecting various cytoprotection links, thus being suitable for the treatment and prevention of erosive and ulcerative lesions of the gastrointestinal tract, as well as gastroenterological diseases of various etiologies.

Conflict of interest: The Expert Council meeting was supported by the Alium company.

Association of CHA2 DS2 -VASc Score with Stroke, Thromboembolism, and Death in Hip Fracture Patients

OBJECTIVES

Patients undergoing hip fracture surgery have a 10 times increased risk of stroke compared with the general population. We aimed to evaluate the association between the CHA₂ DS₂ -VASc (congestive heart failure, hypertension, age ≥75 years, diabetes, previous stroke/TIA [transient ischemic attack]/systemic embolism (2 points), vascular disease, age 65-74 years, and female sex) score and the risk of stroke, thromboembolism, and all-cause mortality in patients with hip fracture with or without atrial fibrillation (AF).

DESIGN

Nationwide prospective cohort study.

SETTING

Danish hospitals.

PARTICIPANTS

Subjects were all incident hip fracture patients in Denmark age 65 years and older with surgical repair procedures between 2004 and 2016 (n = 78,096). Participants were identified using the Danish Multidisciplinary Hip Fracture Registry.

MEASUREMENTS

We calculated incidence rates, cumulative incidences, and hazard ratios (HRs) with 95% confidence intervals (CIs) by CHA₂ DS₂ -VASc score, stratified on AF history.

RESULTS

The cumulative incidence of ischemic stroke 1 year after hip fracture increased with ascending CHA₂ DS₂ -VASc score, and it was 1.9% for patients with a score of 1 and 8.6% for patients with a score above 5 in the AF group. Corresponding incidences in the non-AF group were 1.6% and 7.6%. Compared with a CHA₂ DS₂ -VASc score of 1, adjusted HRs were 5.53 (95% CI = 1.37-22.24) among AF patients and 4.91 (95% CI = 3.40-7.10) among non-AF patients with a score above 5. A dose-response-like association was observed for all cardiovascular outcomes. All-cause mortality risks and HRs were substantially higher for all CHA₂ DS₂ -VASc scores above 1 in both the AF group and the non-AF group.

CONCLUSION

Among patients with hip fracture, a higher CHA₂ DS₂ -VASc score was associated with increased risk of stroke, thromboembolism, and death. This finding applied both to patients with and without AF. Patients with high CHA₂ DS₂ -VASc scores had almost similar absolute risks for cardiovascular outcomes, irrespective of AF. J Am Geriatr Soc 68:1698-1705, 2020.

Effects of rivaroxaban on activated clotting time in catheter ablation for atrial fibrillation in Chinese patients

PURPOSE

It has been observed that patients on rivaroxaban require more heparin and frequent activated clotting time (ACT) monitoring throughout the catheter ablation of atrial fibrillation, but the strategy of heparin injection varies in different studies. We sought to examine the determinants of heparin dosage in Chinese patients on rivaroxaban.

METHODS

We reviewed consecutive patients who received rivaroxaban before atrial fibrillation ablation and compared them to patients on no anticoagulant. The dosage of heparin required to achieve ACT > 300 s was evaluated. We then tested determinants of heparin dosage prospectively.

RESULTS

There were 124 patients on rivaroxaban (R group) and 42 on no anticoagulant (NA group) in retrospective study. Heparin dosage required to achieve target ACT was 0.89 ± 0.01 mg/kg in R group and 0.60 ± 0.01 mg/kg in NA group, P < 0.05. The bolus heparin dosage required was 0.77 ± 0.01 mg/kg (96.1 ± 1.1 U/kg) when baseline ACT > 200 s. In the prospective study, 80/90(88.9%) of patients in R group and 79/90(87.8%) in NA group achieved an ACT > 300 s after initial bolus injection of heparin. The ACT 60 min after target ACT (ACT60) in R group was higher than that in NA group (287.5 ± 28.3 VS 238.9 ± 29.5, P < 0.05). Rivaroxaban was the only independent predictor of ACT60. There was no significant difference in ACT or heparin dosage in patients with different duration on or withdrawal of rivaroxaban.

CONCLUSIONS

In patients undergoing atrial fibrillation ablation on rivaroxaban, the effective duration of heparin is prolonged and the procedural heparin requirement is significantly greater. Heparin dosage can be predicted by baseline ACT, but not influenced by duration on or withdrawal of rivaroxaban.