Dabigatran for periprocedural anticoagulation following radiofrequency ablation for atrial fibrillation: a meta-analysis of observational studies

Comparison of peri-procedural anticoagulation with rivaroxaban and apixaban during radiofrequency ablation of atrial fibrillation

INTRODUCTION

Prospective studies on rivaroxaban and apixaban have shown the safety and efficacy of direct anticoagulation agents (DOAC)s used peri-procedurally during radiofrequency ablation (RFA) of atrial fibrillation (AF). Studies comparing the two agents have not been performed.

METHODS

Consecutive patients from a prospective registry who underwent RFA of AF between April 2012 and March 2015 and were on apixaban or rivaroxaban were studied. Clinical variables and outcomes were noted.

RESULTS

There were a total of 358 patients (n = 56 on apixaban and n = 302 on rivaroxaban). There were no differences in baseline characteristics between both groups. The last dose of rivaroxaban was administered the night before the procedure in 96% of patients. In patients on apixaban, 48% of patients whose procedure was in the afternoon took the medication on the morning of the procedure. TIA/CVA occurred in 2 patients (0.6%) in rivaroxaban group with none in apixaban group (p = 0.4). There was no difference in the rate of pericardial effusion between apixaban and rivaroxaban groups [1.7% vs 0.6% (p = 0.4)]. Five percent of patients in both groups had groin complications (p = 0.9). In apixaban group, all groin complications were small hematomas except one patient who had a pseudoaneurysm (1.6%). One pseudo-aneurysm, 1 fistula and 3 large hematomas were noted in patients on rivaroxaban (1.7%) with the rest being small hematomas. DOACs were restarted post procedure typically 4 h post hemostasis.

CONCLUSIONS

Peri-procedural uninterrupted use of apixaban and rivaroxaban during AF RFA is safe and there are no major differences between both groups.

When is it appropriate to stop non-vitamin K antagonist oral anticoagulants before catheter ablation of atrial fibrillation? A multicentre prospective randomized study

Aims

Although a recent expert consensus statement has recommended periprocedural uninterrupted (UI) non-vitamin K antagonist oral anticoagulants (NOACs) during catheter ablation of atrial fibrillation (AF) as a Class I indication, there have been no clear randomized trials. We investigated the safety and efficacy of UI, procedure day single-dose skipped (SDS), and 24-hour skipped (24S) NOACs in patients undergoing AF ablation.

Methods and results

In this prospective, open-label, randomized multicentre trial, 326 patients (75% male, 58 ± 11 years old) scheduled for AF catheter ablation were randomly assigned in a 1:1:1 ratio to UI, SDS, and 24S at three tertiary hospitals. Bridging with low molecular weight heparin was carried out in the patients with persistent AF who were assigned to the 24S group. Dabigatran, rivaroxaban, and apixaban were assigned in order after randomization. The primary endpoint was the incidence of bleeding events within 1 month after ablation. The secondary endpoints included thrombo-embolic and other procedure-related complications. The intra-procedural heparin requirement was higher in the 24S group than others (P < 0.001), and the mean activated clotting time was comparable among the groups (P = 0.139). The incidence of major bleeding up to 1 month after ablation and a post-procedural reduction in the haemoglobin levels did not significantly differ among the treatment groups and different NOACs (P > 0.05). There were no fatal events or thrombo-embolic complications in all the three groups.

Conclusion

In patients undergoing AF ablation, UI NOACs and SDS or double dose skipped NOACs had a comparable efficacy and safety, regardless of the type of NOAC.

Safety And Efficacy Of Uninterrupted Periprocedural Apixaban In Patients Undergoing Atrial Fibrillation Catheter Ablation: A Metaanalysis Of 1,057 Patients

Apixaban (factor Xa inhibitor) is a novel anticoagulant and may be beneficial during atrial fibrillation (AF) ablation for prevention of thromboembolic events. However, the adverse effects of periprocedural apixaban therapy have not been thoroughly evaluated. A meta-analysis was performed to evaluate the safety of apixaban for anticoagulation in AF ablation. We searched the online databases till October 2015 for studies comparing Apixaban with Vitamin K antagonists in atrial fibrillation patients undergoing catheter ablation. Primary outcome of our study was composite of thromboembolic event and bleeding (includes major and minor bleeding). A total of 1,057 atrial fibrillation patients in 3 studies undergoing catheter ablation were included in this analysis. Zero thromboembolic events were reported in the apixaban group and 1 in the VKA group with no statistical difference (OR 0.75; 95% CI 0.03-18.49). No major differences were observed for the primary outcome (OR 0.92; 95% CI 0.54-1.55), risk of overall bleeding (OR 0.94, 95% CI 0.55- 1.58), major bleeding (OR1.37; 95% CI 0.33-5.67), minor bleeding (OR 0.89; 95% CI 0.50-1.55), pericardial effusion (OR 0.50; 95% CI 0.18-1.38) and groin hematoma (OR 1.36; 95% CI 0.70-2.65). Uninterrupted apixaban administration in patients undergoing AF catheter ablation was non-inferior to VKA without increasing the risk of major and minor bleeding.

Risk-Benefit Profile of Direct-Acting Oral Anticoagulants in Established Therapeutic Indications: An Overview of Systematic Reviews and Observational Studies

Since 2008, the direct-acting oral anticoagulants (DOACs) have expanded the therapeutic options of cardiovascular diseases with recognized clinical and epidemiological impact, such as non-valvular atrial fibrillation (NVAF) and venous thromboembolism (VTE), and also in the preventive setting of orthopedic surgical patients. The large body of evidence, not only from pivotal clinical trials but also from 'real-world' postmarketing observational findings (e.g. analytical epidemiological studies and registry data) gathered to date allow for a first attempt at verifying a posteriori whether or not the pharmacological advantages of the DOACs actually translate into therapeutic innovation, with relevant implications for clinicians, regulators and patients. This review aims to synthesize the risk-benefit profile of DOACs in the aforementioned consolidated indications through an 'evidence summary' approach gathering the existent evidence-based data, particularly systematic reviews with meta-analyses of randomized controlled trials, as well as observational studies, comparing DOACs with vitamin K antagonists. Clinical evidence will be discussed and compared with major international guidelines to identify whether an update is needed. Controversial clinically relevant safety issues will be also examined in order to highlight current challenges and unsettled questions (e.g. actual bleeding risk in susceptible populations). It is anticipated that the large number of publications on NVAF or VTE (44 systematic reviews with meta-analyses and 12 observational studies retained in our analysis) suggests the potential existence of overlapping studies and calls for common criteria to qualitatively and quantitatively assess discordances, thus guiding future research.

Efficacy and Safety of Novel Oral Anticoagulants for Atrial Fibrillation Ablation: An Updated Meta-Analysis

INTRODUCTION

Novel oral anticoagulants (NOACs) have been approved for prevention of stroke and systemic embolism in patients with non-valvular atrial fibrillation (NVAF). A large number of patients are on NOACs when they present for AF ablation. We intended to evaluate the safety and efficacy of NOACs for AF ablation during the periprocedural period by performing a meta-analysis of trials comparing NOACs with warfarin.

METHODS

Studies comparing NOACs (dabigatran and rivaroxaban) with warfarin as periprocedural anticoagulants for AF ablation were identified using an electronic search. Primary outcomes were: (1) a composite endpoint of stroke, transient ischemic attack (TIA), peripheral arterial embolism, or silent cerebral lesions on magnetic resonance imaging (MRI) and (2) major bleeding complications. A random effects model was used to pool the safety and efficacy data across all included trials.

RESULTS

When compared to warfarin, there was an increased risk of the composite endpoint of stroke, TIA, peripheral arterial embolism, or silent cerebral lesions on MRI with NOACs as periprocedural anticoagulants for AF ablation [odds ratio (OR): 1.69, 95% confidence interval (CI): 1.06-2.68]. Sub-group analysis revealed a higher risk of composite endpoint with dabigatran as a periprocedural anticoagulant for AF ablation (OR: 2.01, 95% CI: 1.19-3.39) whereas the risk was similar with rivaroxaban (OR: 0.90, 95% CI: 0.34-2.41). Sensitivity analysis after excluding silent cerebral lesions on MRI showed there was no increased risk of thromboembolic events with either dabigatran (OR: 1.69, 95% CI: 0.81-3.51) or rivaroxaban (OR: 0.70, 95% CI: 0.12-4.04). Risk of bleeding with NOACs was similar to warfarin (OR: 0.91, 95% CI: 0.62-1.34).

CONCLUSION

NOACs are comparable to warfarin in terms of bleeding complications. However, dabigatran therapy is potentially associated with a higher risk of silent cerebral lesions on MRI. The results of this study should be considered as hypothesis-generating and assessed further in prospective randomized clinical studies.

Are Some Anticoagulants More Equal Than Others? - Evaluating the Role of Novel Oral Anticoagulants in AF Ablation

Left atrial ablation strategies are being increasingly performed as a Class 1 therapeutic indication for drug refractory paroxysmal atrial fibrillation (AF). Traditionally AF ablation has been performed with patients on uninterrupted warfarin therapy, however over the last few years, novel oral anticoagulants (NOACs) have emerged as attractive alternatives to warfarin in order to reduce stroke risk due to AF. NOACs are therefore increasingly being used instead of warfarin in the management of AF. There is also mounting evidence mainly in the form of small randomised studies and meta-analysis that have demonstrated that the use of NOACs for AF ablation is efficacious, safe and convenient. However the peri-procedural dosing protocols used in various studies especially in terms of whether NOAC use is interrupted or uninterrupted during AF ablation, have significant inter-operator and inter-institution variability. Currently there is also a lack of randomised controlled trials to validate the data obtained from meta-analyses. There is also evidence that use of NOACs may increase the requirement of unfractionated heparin during the procedure. This review article shall examine the currently available evidence-base, appraise the gaps in the current evidence and also underscore the need for larger randomised clinical trials in this rapidly developing field.

Network meta-analysis of efficacy and safety of competitive oral anticoagulants in patients undergoing radiofrequency catheter ablation of atrial fibrillation

PURPOSE

The aim of this network meta-analysis was to evaluate the comparative efficacy and safety of dabigatran, rivaroxaban, apixaban, interrupted vitamin K antagonist (I-VKA), and continuous VKA (C-VKA) in patients undergoing radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF).

METHODS

PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials were searched to identify clinical trials comparing dabigatran, rivaroxaban, or apixaban with I-VKA or C-VKA, or against each other, in AF patients undergoing RFCA. A network meta-analysis was conducted to directly and indirectly compare the efficacy and safety of competitive anticoagulation regimens with a Bayesian random-effects model.

RESULTS

A total of 39 studies enrolling 27,766 patients were included. C-VKA demonstrated significant superiority over I-VKA in reducing thromboembolic events (risk difference [RD] -0.0068, 95 % confidence interval [CI] -0.0106 to -0.0032) and major bleeding complications (RD -0.0044, 95 % CI -0.0098 to -0.0006). Rivaroxaban compared with I-VKA was associated with a lower risk of thromboembolism (RD -0.0073, 95 % CI -0.0134 to -0.0012), being at the best ranking position among all of the compared anticoagulation regimens in terms of both the efficacy and safety. None of the remaining comparisons reached statistically significant difference in the rate of thromboembolism or major bleeding.

CONCLUSIONS

The present study suggests that C-VKA is superior to I-VKA for AF patients undergoing RFCA. Rivaroxaban is the highest probability to be the optimal alternative to C-VKA among the three non-VKA oral anticoagulants in AF ablation.

Apixaban versus Warfarin for the Prevention of Periprocedural Cerebral Thromboembolism in Atrial Fibrillation Ablation: Multicenter Prospective Randomized Study

INTRODUCTION

Stroke can be a life-threatening complication of atrial fibrillation (AF) catheter ablation. Uninterrupted warfarin treatment contributes to minimizing the risk of stroke complications.

METHODS AND RESULTS

This was a prospective, open-label, randomized, multicenter study assessing the safety and efficacy of apixaban for the prevention of cerebral thromboembolism complicating AF catheter ablation. Two hundred patients with drug-resistant AF were equally assigned to take either apixaban (5 mg or 2.5 mg twice daily) or warfarin (target international normalized ratio, 2-3) for at least 1 month before AF ablation. Neither drug regimen was interrupted throughout the operative period. Diffusion-weighted magnetic resonance imaging was performed for all patients to detect silent cerebral infarction (SCI) after the ablation. Primary outcomes were defined as the occurrence of stroke, transient ischemic attack, SCI, or major bleeding that required intervention. The secondary outcome was minor bleeding. The groups did not statistically differ in patients' backgrounds or procedural parameters. During AF ablation, the apixaban group required administration of more heparin to maintain an activated clotting time > 300 seconds than the warfarin group (apixaban, 14,000 ± 4,000 units; warfarin, 9,000 ± 3,000 units). Three primary outcome events occurred in each group (apixaban, 2 SCI and 1 major bleed; warfarin, 3 SCI, P = 1.00), and 3 and 4 secondary outcome events occurred in the apixaban and warfarin groups (P = 0.70), respectively.

CONCLUSION

Apixaban has similar safety and effectiveness to warfarin for the prevention of cerebral thromboembolism during the periprocedural period of AF ablation.

Almanac 2015: atrial fibrillation research in Heart

Atrial fibrillation continues to attract interest in the cardiovascular community and in Heart. Over 60 original research and review papers published in Heart in 2014–2015 cover various aspects of atrial fibrillation, from associated conditions and precipitating factors to new approaches to management. Here, we provide an overview of articles on atrial fibrillation published in Heart in 2014–2015, highlighting new developments, emerging concepts and novel approaches to treatment.

Bleeding risks with novel oral anticoagulants during catheter ablation of atrial fibrillation: a systematic review and network meta-analysis

BACKGROUND

Comprehensive comparisons of safety (measured by bleeding risk) between multiple novel oral anticoagulants (NOACs and warfarin) in the peri-procedural period of catheter ablation (CA) for atrial fibrillation (AF) are rare.

METHODS AND RESULTS

MEDLINE, EMBASE, and COCHRANE LIBRARY were searched up to February 2015 by two reviewers independently. Predefined inclusion criteria identified 24 studies which were included in the analysis. Data were extracted by two researchers, and a network meta-analysis was conducted in R with R2WinBugS package, within Bayesian framework. Pooled odds ratios (OR) and 95% confidence intervals (CI) were summarized to evaluate the bleeding risks of three novel anticoagulants (dabigatran, rivaroxaban, apixaban) in AF patients undergoing catheter ablation (CA). With respect to total bleeding risk, no significant difference was observed between dabigatran, rivaroxaban, apixaban, and vitamin K antagonists (VKAs) by mixed-treatment comparison. The similar results were seen in the direct comparison. While dabigatran was associated with a lower rate of minor bleeding in comparison to VKAs (OR = 0.67 with 95%CI 0.49-0.93).

CONCLUSIONS

Risks of bleeding with dabigatran, rivaroxaban, apixaban, and VKAs were similar in peri-procedural period of CA for AF.

Low dose dabigatran versus uninterrupted acenocoumarol for peri-procedural anticoagulation in atrial fibrillation catheter ablation

BACKGROUND

Left atrial ablation for atrial fibrillation (AF) is associated with a transiently increased risk of thromboembolic and hemorrhagic events. We tested the hypothesis that the low dose dabigatran [110mg twice a day (bid)] can be safely used as an alternative to uninterrupted acenocoumarol for periprocedural anticoagulation in left atrial ablation procedures.

METHODS AND RESULTS

A total of 149 consecutive patients undergoing pulmonary vein antral isolation for AF were included; 64 patients were on low dose dabigatran (110mg bid) and 85 patients were on acenocoumarol with therapeutic international normalized ratios. Two doses of dabigatran were withheld before the procedure and the drug was restarted 4hours after vascular hemostasis. Overall, the two groups were well-matched. Hemorrhagic and thromboembolic complications were similar in both groups within 90days from the procedure (4.7% for the dabigatran group versus 9.4% for the acenocoumarol group; P=0.275). Major hemorrhage occurred in 1.6% in the dabigatran group versus 3.5% in the acenocoumarol group (P=0.462). A single thromboembolic event occurred in the dabigatran group (1.6%) versus 2 (2.4%) in the acenocoumarol group (P=0.734). Despite higher doses of intraprocedural heparin (P<0.01), the mean activated clotting time was significantly lower in patients who were on dabigatran than those on acenocoumarol (P<0.01).

CONCLUSIONS

The low dose dabigatran regimen provides safe and effective peri-procedural anticoagulation in patients undergoing left atrial ablation for AF compared with uninterrupted acenocoumarol therapy.

Dabigatran for the prevention and treatment of thromboembolic disorders

Dabigatran, an oral direct thrombin inhibitor, was the first of a new class of drugs referred to as non-vitamin K oral anticoagulants. Dabigatran is better than warfarin for stroke prevention in non-valvular atrial fibrillation (dose of 150 mg twice a day), non-inferior to enoxaparin for venous thromboembolism prevention after orthopedic surgery and non-inferior to warfarin in preventing recurrence after acute venous thromboembolism. The safety profile is similar to standard anticoagulants, with significant reduction observed in intracranial hemorrhage. Other advantages include a rapid onset of action and a predictable pharmacokinetic profile, allowing a fixed-dose regimen without the need for routine anticoagulation monitoring. In the event of bleeding, general support measures are recommended and if severe, the use of non-specific hemostatic agents such as prothrombin complex concentrates and recombinant factor VIIa must be considered. A specific reversal agent (idarucizumab) is in development.

Periprocedural Management of New Oral Anticoagulants in Atrial Fibrillation Ablation

BACKGROUND

Patients who undergo catheter ablation for atrial fibrillation (AF) are at increased risk of developing thromboembolic and bleeding complications periprocedurally. Many patients are now on newer oral anticoagulants (NOACs), but data regarding their safety and efficacy during AF ablation are limited.

METHODS AND RESULTS

This article reviews the literature in PubMed from 1998 to 2014 and includes clinical trials and meta-analysis that analyzed the safety and efficacy of NOACs during AF catheter ablation. Dabigatran seems to be as effective and safe as warfarin, although most data are from single-center studies, with small samples and very low overall bleeding and thromboembolic complications. Periprocedural anticoagulation protocols also vary greatly between studies. Some recent meta-analysis has shown that warfarin could still be a safer and more effective alternative. There are fewer studies with rivaroxaban in AF ablation, and there have been no meta-analysis yet comparing rivaroxaban to warfarin or dabigatran. There seems to be no significant differences in safety or efficacy of rivaroxaban compared to warfarin. Interestingly, there are no available data for apixaban in AF ablation yet.

DISCUSSION

There are no consensus guidelines regarding the use of NOACs during AF ablation. Dabigatran and rivaroxaban seem as safe and effective as warfarin, although larger studies with standardized protocols are needed, as available studies may be underpowered to detect small differences in bleeding and thromboembolic rates.

Feasibility and safety of uninterrupted dabigatran therapy in patients undergoing ablation for atrial fibrillation

OBJECTIVE

Uninterrupted oral warfarin strategy has become the standard protocol to prevent complications during catheter ablation (CA) for the treatment of atrial fibrillation (AF). However, little is known about the safety and efficacy of uninterrupted dabigatran therapy in patients undergoing CA for AF. Therefore, this study investigated the safety and efficacy of uninterrupted dabigatran therapy and compared the findings with those for uninterrupted warfarin therapy.

METHODS

Bleeding and thromboembolic events during the periprocedural period were evaluated in 363 consecutive patients who underwent CA for AF at Nagoya University Hospital, and received uninterrupted dabigatran (n=173) or uninterrupted warfarin (n=190) for periprocedural anticoagulation.

RESULTS

A total of 27 (7%) patients experienced either bleeding or thromboembolic complications. Major bleeding complications occurred in 2 (1%) patients in the dabigatran group (DG) and 2 (1%) patients in the warfarin group (WG). Eight (5%) patients in the DG and 9 (5%) patients in the WG experienced groin hematoma, a type of minor bleeding complication. Meanwhile, no patient in the DG and 1 (1%) in the WG developed cerebral ischemic stroke. Overall, there was no significant difference between the groups for any category. The activated partial thromboplastin time (APTT) independently predicted periprocedural complications in the DG.

CONCLUSION

Uninterrupted dabigatran therapy in CA for AF thus may be a safe and effective anticoagulant therapy, and appears to be closely similar to continuous warfarin; however, it is essential to pay close attention to the APTT values when using dabigatran during CA.

My Patient Taking A Novel Oral Anticoagulant Needs Surgery, Device Implantation, Or Ablation

Atrial fibrillation (AF) is a highly prevalent chronic condition and a growing number of patients are on chronic anticoagulation therapy with novel oral anticoagulant (NOAC) agents: dabigatran, rivaroxaban, and apixaban. Many of these patients are expected to require invasive procedures. There is no clear consensus regarding the peri-procedural management of patients using NOACs, as to how to minimize both bleeding risk and thromboembolism risk. This review of the current available literature is designed to help formulate peri-procedural anticoagulation strategies for patients with AF taking NOACs who are being considered for catheter ablation, device implant, or other surgery. To help frame the discussion, we offer 3 case vignettes that we will revisit to at the end of the review of the existing literature. Case 1: A 62 year-old female with hypertension, diabetes, and symptomatic paroxysmal AF who is prescribed dabigatran for thromboembolism prevention. She has failed attempts at maintaining sinus rhythm with antiarrhythmic drugs. She is now being considered for catheter ablation of AF. Case 2: A 76 year-old male with hypertension, diabetes, prior stroke, and ischemic cardiomyopathy who has persistent drug-refractory AF. He is maintained on chronic anticoagulation with dabigatran for thromboembolism prevention. He has an implantable cardioverter-defibrillator (ICD) which requires a generator change. Case 3: A 58 year-old male with hypertension and paroxysmal AF who takes rivaroxaban for thromboembolic prophylaxis and is being considered for a knee replacement surgery.

Warfarin versus dabigatran etexilate: an assessment of efficacy and safety in patients with atrial fibrillation

INTRODUCTION

Oral anticoagulation is the mainstay for stroke and thromboembolic event prevention in patients with atrial fibrillation (AF). Given limitations of warfarin therapy, non-vitamin K oral anticoagulants have been developed including direct thrombin inhibitors (i.e., dabigatran etexilate). Dabigatran etexilate has been tested thoroughly in terms of efficacy and safety in clinical trials and studies, involving 'real-world' cohorts. In this review, currently available evidence in patients with non-valvular AF is discussed.

AREAS COVERED

The pharmacology, efficacy and safety, and current aspects of use of dabigatran etexilate in patients with non-valvular AF are reviewed in a comparative manner to warfarin both for chronic anticoagulation and in different clinical settings.

EXPERT OPINION

Dabigatran etexilate appeared to have several pharmacokinetic and pharmacodynamic advantages over warfarin, as well as a favorable efficacy and safety profile being at least noninferior and often superior to warfarin in patients with non-valvular AF. The latter was shown in the clinical trials, meta-analyses and studies with 'real-world' data. Currently ongoing trials will expand the body of evidence on warfarin and will aid decision making in currently controversial areas. Important limitations of dabigatran etexilate include contraindications for its use in patients with prosthetic heart valves and end-stage chronic kidney disease.

Peri-procedural interrupted oral anticoagulation for atrial fibrillation ablation: comparison of aspirin, warfarin, dabigatran, and rivaroxaban

Aims

Atrial fibrillation ablation requires peri-procedural oral anticoagulation (OAC) to prevent thromboembolic events. There are several options for OAC. We evaluate peri-procedural AF ablation complications using a variety of peri-procedural OACs.

Methods and results

We examined peri-procedural OAC and groin, bleeding, and thromboembolic complications for 2334 consecutive AF ablations using open irrigated-tip radiofrequency (RF) catheters. Pre-ablation OAC was warfarin in 1113 (47.7%), dabigatran 426 (18.3%), rivaroxaban 187 (8.0%), aspirin 472 (20.2%), and none 136 (5.8%). Oral anticoagulation was always interrupted and intraprocedural anticoagulation was unfractionated heparin (activated clotting time, ACT = 237 ± 26 s). Pre- and post-OAC drugs were the same for 1591 (68.2%) and were different for 743 (31.8%). Following ablation, 693 (29.7%) were treated with dabigatran and 291 (12.5%) were treated with rivaroxaban. There were no problems changing from one OAC pre-ablation to another post-ablation. Complications included 12 (0.51%) pericardial tamponades [no differences for dabigatran (P = 0.457) or rivaroxaban (P = 0.163) compared with warfarin], 12 (0.51%) groin complications [no differences for rivaroxaban (P = 0.709) and fewer for dabigatran (P = 0.041) compared with warfarin]. Only 5 of 2334 (0.21%) required blood transfusions. There were two strokes (0.086%) and no transient ischaemic attacks (TIAs) in the first 48 h post-ablation. Three additional strokes (0.13%), and two TIAs (0.086%) occurred from 48 h to 30 days. Only one stroke had a residual deficit. Compared with warfarin, the neurologic event rate was not different for dabigatran (P = 0.684) or rivaroxaban (P = 0.612).

Conclusion

Using interrupted OAC, low target intraprocedural ACT, and irrigated-tip RF, the rate of peri-procedural groin, haemorrhagic, and thromboembolic complications was extremely low. There were only minimal differences between OACs. Low-risk patients may remain on aspirin/no OAC pre-ablation. There are no problems changing from one OAC pre-ablation to another post-ablation.

The Rate Of Complications Associated With Concomitant Use Of Dabigatran With Cryoballoon Ablation For Atrial Fibrillation

INTRODUCTION

Catheter ablation is an evolving therapeutic strategy for the management of atrial fibrillation (AF). It is associated with a risk of thromboembolic events. The peri-procedural anticoagulation management with warfarin has been successful in mitigating this risk. However, introduction of novel oral anticoagulants like dabigatran offers more flexibility in anticoagulation approaches. Previous studies had evaluated the safety and efficacy of dabigatran in the radiofrequency ablation, but data related to cryoballoon ablation is lacking.

METHODS AND RESULTS

We performed a retrospective observational study involving patients who underwent cryoballoon ablation for drug-refractory, symptomatic AF while on dabigatran in periprocedural period. Thromboembolic, hemorrhagic or other complications occurring within the first 30 days after the ablation procedure were analyzed. Our study population comprised of 50 patients with mean age of 58.96 ± 3.54 years with 76% (n=38) being male. We found 3 (6%) minor complications in peri-procedural period including 2 groin hematomas and 1 trace asymptomatic pericardial effusion. There were no major intraprocedural or post procedural hemorrhagic or thromboembolic events. None of patients with the minor complications required significant additional workup or extended hospital stay. All the patients were able to continue dabigatran for 30 days without any additional side effects or complications.

CONCLUSION

Dabigatran is a safe and efficacious agent in patients undergoing cryoballoon AF ablation.

Comparative safety of periablation anticoagulation strategies for atrial fibrillation: data from a large multicenter study

BACKGROUND

There are a variety of periprocedural anticoagulation strategies for atrial fibrillation (AF) ablation, including the use of dabigatran. It is unclear which strategy is superior.

OBJECTIVE

To compare the safety and efficacy of anticoagulation with uninterrupted warfarin, dabigatran, and warfarin with heparin bridging in patients undergoing ablation of AF at four experienced centers.

METHODS AND RESULTS

In this retrospective analysis, 882 patients (mean age: 61 ± 11 years) underwent ablation of AF using uninterrupted warfarin (n = 276), dabigatran (n = 374), or warfarin with heparin bridging (n = 232) for periprocedural anticoagulation. The rate of total complications was 23/276 (8.3%) in the uninterrupted warfarin group, 30/374 (8.0%) in the dabigatran group, and 29/232 (12.5%) in the bridged group (P = 0.15). Major complications were more frequent in the uninterrupted warfarin group 12/276 (4.3%) compared with 3/374 (0.8%) in dabigatran and 6/232 (2.6%) in the bridged group (P = 0.01). The most common major complication was the need for transfusion or occurrence of major bleeding. Minor complications did not differ among the three groups. On multivariate analysis, female gender (odds ratio [OR] 1.93, confidence interval [CI] 1.16-3.19, P = 0.011), bridging heparin (OR 2.13, CI 1.100-3.941, P = 0.016), use of triple antithrombotic therapy (OR 1.77, CI 1.05-2.98, P = 0.033), and prior myocardial infarction (OR 2.40, CI 1.01-5.67, P = 0.046) independently predicted total complications.

CONCLUSIONS

When comparing the use of uninterrupted warfarin, dabigatran, and warfarin with heparin bridging in patients undergoing catheter ablation of AF, dabigatran was not associated with increased risk, major complications were more common in the uninterrupted warfarin group, and after adjustment, warfarin with bridging increased total complications.

Atrial Fibrillation and Stroke: Increasing Stroke Risk with Intervention

This article focuses on the important newly recognized appreciation for the paradoxic increase in stroke and transient ischemic attack as a result of intervention meant to treat atrial fibrillation (AF) with the hope of decreasing stroke risk in the long term. The impact of silent cerebral lesions has recently been identified as a potentially major limitation, and the risks with AF ablation, as well as the present understanding of how risk can be minimized, are explained. This article provides a platform for newer study, changes in the way procedures are done, and possibly vascular-based stroke-reduction strategies.

The Safetyof Dabigatran Versus Warfarin in Patients Undergoing Atrial Fibrillation Ablation

The safety and optimal strategy of the use of dabigatran versus uninterrupted warfarin in atrial fibrillation ablation is currently unclear. We performed a retrospective analysis between July 2011-October 2012 of all patients undergoing an AF ablation who received uninterrupted warfarin therapy (199) and the routine cessation of Dabigatran therapy (126) 4 days pre-ablation. Major safety endpoints included: pericardial effusion (requiring pericardiocentesis), peripheral thromboembolism, CVA, and groin hematoma requiring blood transfusion. Minor endpoints included pericardial effusion and groin hematoma. Dabigatran was restarted the following day after ablation. The warfarin group was older, had a higher CHADS₂, CHA₂DS₂VASc and HASBLED scores and greater prevalence of aortic plaque. The major complication rate was 2.0% in the warfarin group and 2.4% in the dabigatran group (P= 0.83). The minor complication rate was 2.5% in the warfarin group and <1% in the dabigatran group (P= 0.27). In the dabigatran group, there was one renal thromboembolic event 4 days post-ablation. All patients in the warfarin group who suffered a major complication required a blood transfusion. Cessation of dabigatran therapy 4 days pre AF ablation has a comparable safety profile to uninterrupted warfarin therapy.

Post-Procedural Dabigatran Versus Interrupted Warfarin Therapy Following Catheter Ablation for Atrial Fibrillation

PURPOSE

Patients undergoing catheter ablation for atrial fibrillation (AF) are at a higher risk of thromboembolic events post-procedure and therefore require therapeutic anticoagulation after ablation. Anticoagulation strategies include performing the procedure on or off therapeutic warfarin, though the latter approach requires post-procedure bridging therapy with low molecular-weight heparin (LMWH) until a therapeutic INR is achieved. The purpose of this study is to compare the safety and efficacy of post-ablation dabigatran as compared to warfarin with LMWH bridging.

METHODS

We performed a single-center retrospective analysis of consecutive patients who underwent catheter ablation for AF between January 2010 and December 2012 and received either post-procedure warfarin with a LMWH bridge or dabigatran. Warfarin was started the night of ablation; LMWH was started the next morning and continued until the INR was ≥ 2.0. Dabigatran was started the morning post-ablation.

RESULTS

The analysis included 324 patients. Of these, mean age was 60 ± 9 years, 78% were male, 81% had CHADS₂ scores of 0 or 1, and 181 (56%) received dabigatran post-ablation. Patients who received dabigatran had lower CHADS₂ scores and were more likely to be in NYHA Class I. At 30-days post-procedure, there were 0 thromboembolic or bleeding complications in the dabigatran group versus 4 (2.8%) in the warfarin group (p=0.037). There were no deaths in either group at 30 days post-ablation.

CONCLUSIONS

Post-ablation dabigatran appears safe and efficacious compared to an interrupted warfarin strategy with LMWH bridging.

Atrial Fibrillation and Stroke - Increasing Stroke Risk With Intervention

In this review, we focus on the important newly recognized appreciation for the paradoxical increase in stroke and TIA as a result of intervention meant to treat atrial fibrillation (AF) with the hope of decreasing stroke risk in the long term. The impact of silent cerebral lesions recently appreciated as a potentially major limitation and risk with AF ablation is explained. We categorize our present understanding of how we can minimize risk and provide a platform for what will undoubtedly be newer study, changes in the way procedures are done today, and possibly vascular-based stroke-reduction strategies.