Periprocedural Management of Novel Oral Anticoagulants During Atrial Fibrillation Ablation: Controversies and Review of the Current Evidence

Interrupted versus uninterrupted anticoagulation therapy for catheter ablation in adults with arrhythmias

BACKGROUND

The management of anticoagulation therapy around the time of catheter ablation (CA) procedure for adults with arrhythmia is critical and yet is variable in clinical practice. The ideal approach for safe and effective perioperative management should balance the risk of bleeding during uninterrupted anticoagulation while minimising the risk of thromboembolic events with interrupted therapy.

OBJECTIVES

To compare the efficacy and harms of interrupted versus uninterrupted anticoagulation therapy for catheter ablation (CA) in adults with arrhythmias.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, and SCI-Expanded on the Web of Science for randomised controlled trials on 5 January 2021. We also searched three registers on 29 May 2021 to identify ongoing or unpublished trials. We performed backward and forward searches on reference lists of included trials and other systematic reviews and contacted experts in the field. We applied no restrictions on language or publication status.

SELECTION CRITERIA

We included randomised controlled trials comparing uninterrupted anticoagulation with any modality of interruption with or without heparin bridging for CA in adults aged 18 years or older with arrhythmia.

DATA COLLECTION AND ANALYSIS

Two review authors conducted independent screening, data extraction, and assessment of risk of bias. A third review author resolved disagreements. We extracted data on study population, interruption strategy, ablation procedure, thromboembolic events (stroke or systemic embolism), major and minor bleeding, asymptomatic thromboembolic events, cardiovascular and all-cause mortality, quality of life (QoL), length of hospital stay, cost, and source of funding. We used GRADE to assess the certainty of the evidence.  MAIN RESULTS: We identified 12 studies (4714 participants) that compared uninterrupted periprocedural anticoagulation with interrupted anticoagulation. Studies performed an interruption strategy by either a complete interruption (one study) or by a minimal interruption (11 studies), of which a single-dose skipped strategy was used (nine studies) or two-dose skipped strategy (two studies), with or without heparin bridging. Studies included participants with a mean age of 65 years or greater, with only two studies conducted in relatively younger individuals (mean age less than 60 years). Paroxysmal atrial fibrillation (AF) was the primary type of AF in all studies, and seven studies included other types of AF (persistent and long-standing persistent). Most participants had CHADS2 or CHADS2-VASc demonstrating a low-moderate risk of stroke, with almost all participants having normal or mildly reduced renal function. Ablation source using radiofrequency energy was the most common (seven studies). Ten studies (2835 participants) were conducted in East Asian countries (Japan, China, and South Korea), while the remaining two studies were conducted in the USA. Eight studies were conducted in a single centre. Postablation follow-up was variable among studies at less than 30 days (three studies), 30 days (six studies), and more than 30 days postablation (three studies). Overall, the meta-analysis showed high uncertainty of the effect between the interrupted strategy compared to uninterrupted strategy on the primary outcomes of thromboembolic events (risk ratio (RR) 1.76, 95% confidence interval (CI) 0.33 to 9.46; I2 = 59%; 6 studies, 3468 participants; very low-certainty evidence). However, subgroup analysis showed that uninterrupted vitamin A antagonist (VKA) is associated with a lower risk of thromboembolic events without increasing the risk of bleeding. There is also uncertainty on the outcome of major bleeding events (RR 1.10, 95% CI 0.59 to 2.05; I2 = 6%; 10 studies, 4584 participants; low-certainty evidence). The uncertainty was also evident for the secondary outcomes of minor bleeding (RR 1.01, 95% CI 0.46 to 2.22; I2 = 87%; 9 studies, 3843 participants; very low-certainty evidence), all-cause mortality (RR 0.34, 95% CI 0.01 to 8.21; 442 participants; low-certainty evidence) and asymptomatic thromboembolic events (RR 1.45, 95% CI 0.85 to 2.47; I2 = 56%; 6 studies, 1268 participants; very low-certainty evidence). There was a lower risk of the composite endpoint of thromboembolic events (stroke, systemic embolism, major bleeding, and all-cause mortality) in the interrupted compared to uninterrupted arm (RR 0.23, 95% CI 0.07 to 0.81; 1 study, 442 participants; low-certainty evidence). In general, the low event rates, different comparator anticoagulants, and use of different ablation procedures may be the cause of imprecision and heterogeneity observed.

AUTHORS' CONCLUSIONS

This meta-analysis showed that the evidence is uncertain to inform the decision to either interrupt or continue anticoagulation therapy around CA procedure in adults with arrhythmia on outcomes of thromboembolic events, major and minor bleeding, all-cause mortality, asymptomatic thromboembolic events, and a composite endpoint of thromboembolic events (stroke, systemic embolism, major bleeding, and all-cause mortality).  Most studies in the review adopted a minimal interruption strategy which has the advantage of reducing the risk of bleeding while maintaining a lower level of anticoagulation to prevent periprocedural thromboembolism, hence low event rates on the primary outcomes of thromboembolism and bleeding. The one study that adopted a complete interruption of VKA showed that uninterrupted VKA reduces the risk of thromboembolism without increasing the risk of bleeding. Hence, future trials with larger samples, tailored to a more generalisable population and using homogeneous periprocedural anticoagulant therapy and ablation source are required to address the safety and efficacy of the optimal management of anticoagulant therapy prior to ablation.

Contemporary Management of Direct Oral Anticoagulants During Cardioversion and Ablation for Nonvalvular Atrial Fibrillation

As overall prevalence of atrial fibrillation (AF) continues to rise, the number of patients who undergo ablation, or electrical/chemical cardioversion, to restore normal sinus rhythm continues to increase as well. As direct oral anticoagulants (DOACs) have continued to be incorporated into clinical practice for long-term anticoagulation for AF, experience with how best to manage use of DOACs during electrophysiologic procedures is evolving. This review is intended to provide health care providers with a summary of current evidence regarding the use of DOACs during cardioversion and catheter ablation and provide key considerations for their use during such electrophysiologic procedures. PubMed and MEDLINE were searched from inception through June 2018 for studies in humans comparing DOACs alone or against vitamin K antagonists (VKAs) in adult patients (> 18 yrs) who underwent cardioversion or AF catheter ablation using the following key words: "rivaroxaban," "dabigatran," "apixaban," "edoxaban," "non-vitamin K antagonists," "direct or new oral anticoagulants," "warfarin," "vitamin K antagonists," "cardioversion," "ablation of atrial fibrillation," "uninterrupted," and "catheter ablation." Four retrospective studies and three prospective trials comparing DOACs with VKA in patients undergoing cardioversion and three prospective studies in patients undergoing catheter ablation for AF were identified. Observational data and meta-analyses were also critically reviewed. Prospective trials to date suggest similar efficacy and safety with using DOACs in the setting of cardioversion and AF ablation compared to traditional therapy with VKA, with or without bridging. Injectable anticoagulant overlap can be avoided in patients receiving DOACs in the setting of cardioversion for AF. Minimal interruption in anticoagulation may be only necessary for AF ablation in those with highest bleeding risk, such as in renal dysfunction and where drug-drug interactions may increase risk for anticoagulant accumulation. Periprocedural advantages of DOACs include convenience, rapid and predictable onset of effect, improved patient satisfaction, and potential for reduced costs.

Periprocedural Management of Direct Oral Anticoagulants Surrounding Cardioversion and Invasive Electrophysiological Procedures

Supplemental Digital Content is available in the text.

As direct oral anticoagulants (DOACs) have demonstrated favorable efficacy and safety outcomes compared with vitamin K antagonists for the treatment and prevention of venous thromboembolism and the prevention of stroke and systemic embolism in patients with nonvalvular atrial fibrillation, their role in the management of anticoagulation during electrophysiological procedures continues to evolve. At present, guidelines are limited regarding specific recommendations for the use of DOACs in these clinical settings. Here, we review available data regarding the risks and benefits associated with various periprocedural anticoagulation management approaches when patients receiving DOACs undergo electrophysiologic procedures including cardioversion, ablation, and device implantation. This discussion is intended to provide clinicians with an overview of available evidence and best practices to minimize the risk of both thromboembolic and bleeding events in the periprocedural setting.

Reversal Agents in the Era of NOACs

The incidence and prevalence of atrial fibrillation (AF) is expected to more than double between 2010 and 2030. Accordingly, the use of non-vitamin K oral anticoagulant (NOAC) agents for thromboembolic stroke prevention is anticipated to increase. The development of effective and safe antidotes is needed to address the unmet need for rapid anticoagulation reversal. The immediate role for these novel antidotes is for reversal of NOAC activity in life threatening bleeding and urgent surgical intervention. In addition, reversal agents may play an important role in simplifying bridging protocols in the peri-procedural period for catheter ablation of AF and elective surgery. Currently, novel reversal agents are either decoy drug receptors or small molecule non-specific anticoagulant activity inhibitors. These agents are at various stages of FDA investigation and approval, with emerging prospective data for safety and efficacy. The purpose of this review is to outline the currently developed NOAC molecular antagonists, their potential clinical roles and future directions.

Report of periprocedural oral anticoagulants in catheter ablation for atrial fibrillation: The Japanese Catheter Ablation Registry of Atrial Fibrillation (J-CARAF)

BACKGROUND

To obtain a perspective of the current status of catheter ablation for the cure of atrial fibrillation, the Japanese Heart Rhythm Society conducted a nationwide survey: the Japanese Catheter Ablation Registry of Atrial Fibrillation. In this report, we aimed to evaluate the periprocedural use of direct oral anticoagulants with respect to thromboembolic or bleeding complications.

METHODS

Using an online questionnaire, the Japanese Heart Rhythm Society requested electrophysiology centers in Japan to register the relevant data of patients who underwent atrial fibrillation ablation over selected five-months from 2011 to 2014. We compared the clinical profiles and the ablation data, including the incidence of pericardial effusion, major bleeding, and ischemic stroke among patients with periprocedural use of warfarin or a direct oral anticoagulant.

RESULTS

A total of 204 institutions reported data on 6200 atrial fibrillation ablation sessions. We analyzed data obtained from 4698 subjects (Age 63.2±10.6 yr; 73.9% male, 26.1% female) who were administered warfarin or a direct oral anticoagulant, at least up to the day before atrial fibrillation ablation. Warfarin was administered to 54.7% of patients. Dabigatran, rivaroxaban, and apixaban were used in 21.9%, 12.9%, and 10.6% of patients, respectively. Clinical profiles of apixaban-treated patients were similar to those of warfarin-treated patients; they were different from the clinical profiles of patients treated with dabigatran or rivaroxaban. There were 104 complications in 103 subjects (2.2%). Complications were more frequent in older patients (65.3±8.6 yr vs. 63.1±10.7 yr; P=0.012), patients on chronic hemodialysis (4.9% vs. 1.1%; P=0.001), or those treated with warfarin (66.0% vs. 54.4%; P=0.019). Multiple logistic regression analysis revealed that age (OR, 1.02; 95% CI: 1.00-1.04; P=0.035), chronic hemodialysis (OR, 4.40; CI: 1.68-11.50; P=0.003), and assistance by 3-D mapping system (OR, 0.30; CI: 0.16-0.57; P<0.001) were significantly related to the incidence of complications, while periprocedural direct oral anticoagulant was not a predictive factor for complication.

CONCLUSIONS

Compared with uninterrupted warfarin, the choice of a direct oral anticoagulant as a periprocedural oral anticoagulant did not significantly change the incidence of serious complications.