Effect of pre-procedural interrupted apixaban on heparin anticoagulation during catheter ablation for atrial fibrillation: a prospective observational study

Study of Modifications Induced by Continued Direct Oral Anticoagulant Therapy during Atrial Fibrillation Ablation Procedures on Standard Hemostasis Parameters

Background: Unfractionated heparin (UFH) is used as an anticoagulant during the atrial fibrillation (AF) ablation procedure to prevent the occurrence of thromboembolic events. Guidelines recommend an activated clotting time (ACT) greater than 300 s (s) based on studies of patients treated with vitamin K antagonist (VKA) for their AF. However, direct oral anticoagulants (DOACs) have supplanted VKAs in AF and are now used as first-line therapy. It is recommended not to interrupt them during the procedure, which could interfere with the ACT measures. Objective: To assess the real-life relationship between ACT, DOAC concentrations, and UFH anti-Xa activity in patients treated by uninterrupted DOAC therapy. Methods: We conducted a single-center retrospective study. We analyzed consecutive patients with AF who underwent catheter ablation under DOAC therapy. Results: In total, 40 patients were included, including 15 (37.5%), 20 (50.0%), and 5 (12.5%) on rivaroxaban, apixaban, and dabigatran, respectively. Baseline ACT was significantly lower in the apixaban group. ACT was linearly correlated with the residual concentration of apixaban and dabigatran but not with rivaroxaban. After UFH injection, ACT was linearly correlated with the anti-Xa activity, regardless of DOAC. Patients in the apixaban group received a higher total dose of UFH during the procedure to achieve a target ACT > 300 s, which resulted in significantly higher anti-Xa activity during the procedure. Conclusion: Our results raise the question of optimal management of intra-procedural heparin therapy and highlight the limitations of the ACT test, particularly in patients on apixaban.

Uninterrupted DOACs Approach for Catheter Ablation of Atrial Fibrillation: Do DOACs Levels Matter?

Most patients present for catheter ablation of atrial fibrillation (CAAF) with residual or full effect of vitamin K antagonists (VKAs) or direct oral anticoagulants (DOACs). In daily practice, it has been observed that the activated clotting time (ACT) was actually poorly sensitive to the effect of DOACs and that patients on DOACs required more unfractionated heparin (UFH) to achieve the ACT target of 300 s during the procedure, leading some authors to worry about potential overdosing. Conversely, we hypothesize that these higher doses of UFH are necessary to achieve adequate hemostasis during CAAF regardless of the residual effect of DOACs. During CAAF, thrombosis is promoted mainly by the presence of thrombogenic sheaths and catheters in the bloodstream. Preclinical data suggest that only high doses of DOACs are able to mitigate catheter-induced thrombin generation, whereas low dose UFH already do so. In addition, the effect of UFH seems to be lower in patients on DOACs, compared to patients on VKAs, explaining part of the differences observed in heparin requirements. Clinical studies could not identify increased bleeding risk in patients on DOACs compared to those on VKAs despite similar efficacy during CAAF procedures. Moreover, targeting a lower ACT was associated with an increased periprocedural thrombotic risk for both DOAC and VKA patients. Therefore, the low sensitivity of the ACT to the residual effect of DOACs should not be a major concern in its use in the interventional cardiology laboratory.

Running after Activated Clotting Time Values in Patients Receiving Direct Oral Anticoagulants: A Potentially Dangerous Race. Results from a Prospective Study in Atrial Fibrillation Catheter Ablation Procedures

Background: Activated Clotting Time (ACT) guided heparinization is the gold standard for titrating unfractionated heparin (UFH) administration during atrial fibrillation (AF) ablation procedures. The current ACT target (300 s) is based on studies in patients receiving a vitamin K antagonist (VKA). Several studies have shown that in patients receiving Direct Oral Anticoagulants (DOACs), the correlation between ACT values and UFH delivered dose is weak. Objective: To assess the relationship between ACT and real heparin anticoagulant effect measured by anti-Xa activity in patients receiving different anticoagulant treatments. Methods: Patients referred for AF catheter ablation in our centre were prospectively included depending on their anticoagulant type. Results: 113 patients were included, receiving rivaroxaban (n = 30), apixaban (n = 30), dabigatran (n = 30), and VKA (n = 23). To meet target ACT, a higher UFH dose was required in DOAC than VKA patients (14,077.8 IU vs. 9565.2 IU, p < 0.001), leading to a longer time to achieve target ACT (46.5 min vs. 27.3 min, p = 0.001). The correlation of ACT and anti-Xa activity was tighter in the VKA group (Spearman correlation ρ = 0.53), compared to the DOAC group (ρ = 0.19). Despite lower ACT values in the DOAC group, this group demonstrated a higher mean anti-Xa activity compared to the VKA group (1.56 ± 0.39 vs. 1.14 ± 0.36; p = 0.002). Conclusion: Use of a conventional ACT threshold at 300 s during AF ablation procedures leads to a significant increase in UFH administration in patients treated with DOACs. This increase corresponds more likely to an overdosing than a real increase in UFH requirement.

Meta-analysis of the safety and efficacy of using minimally interrupted novel oral anticoagulants in patients undergoing catheter ablation for atrial fibrillation

PURPOSE

The ideal periprocedural anticoagulation strategy for patients being treated with a novel oral anticoagulant (NOAC) during catheter ablation (CA) for atrial fibrillation (AF) is unclear. We evaluated the safety and efficacy of using a minimally interrupted NOAC strategy versus an uninterrupted NOAC or vitamin K antagonist (VKA) strategy during AF ablation.

METHODS

The Cochrane Library, PubMed, and EMBASE databases were searched for randomized controlled or prospective observational studies that compared a minimally interrupted NOAC strategy with an uninterrupted NOAC or VKA strategy from the time of database establishment up to December 2019. The primary endpoints were major bleeding, minor bleeding, and symptomatic thromboembolism. The secondary endpoint was silent cerebral infarction (SCI) as detected by post-ablation brain magnetic resonance imaging (MRI). A measurement of treatment effect for the endpoint was reported as pooled odds ratio (OR) with 95% confidence interval (CI).

RESULTS

A total of 18 studies (6 randomized, 11 observational, and 1 randomized registry) with 6203 patients were included in the final analysis (47% of the patients received minimally interrupted NOAC). There was no significant difference between treatment groups regarding the risk for major bleeding (OR 1.04, 95% CI 0.69-1.57, P = 0.86, I² = 27%). Different stratification methods did not yield significant difference regarding the risk for major bleeding. There was no difference between groups regarding the risk for minor bleeding (P = 1.00) or symptomatic thromboembolism (P = 0.26). Brain MRI results showed that both uninterrupted NOAC (OR 0.44, 95% CI 0.23-0.83, P = 0.01, I² = 72%) and uninterrupted VKA (OR 0.48, 95% CI 0.24-0.97, P = 0.04, I² = 36%) produced a significant reduction in the rate of SCI when compared with minimally interrupted NOAC.

CONCLUSIONS

A periprocedural anticoagulation strategy of minimally interrupted NOAC is not superior to uninterrupted NOAC or VKA when used during AF ablation. There is evidence favoring the use of uninterrupted NOAC or VKA in terms of the risk for SCI.

Perioperative Safety and Efficacy of Different Anticoagulation Strategies With Direct Oral Anticoagulants in Pulmonary Vein Isolation: A Meta-Analysis

OBJECTIVES

The purpose of this study was to evaluate the safety and efficacy of uninterrupted and interrupted direct oral anticoagulant (DOAC) administration in patients undergoing pulmonary vein isolation (PVI).

BACKGROUND

The optimal periprocedural management of DOACs in patients undergoing PVI is not well defined, and different strategies are used.

METHODS

A systematic search of PubMed/MEDLINE, Ovid/MEDLINE, and EMBASE was performed. Three strategies for periprocedural DOAC administration were considered: uninterrupted, mildly interrupted (<12 h), and interrupted (≥12 h). Primary endpoints were major bleeding (MB) and thromboembolic (TE) complications; pooled weighted mean incidence (WMI) was calculated using a random-effects model. A secondary endpoint was the WMI of overall bleeding (OB).

RESULTS

The analysis included 43 studies for a total of 8,362 patients. DOACs showed similar safety and efficacy in the 3 subgroups. The WMI of MB was 1.02%, 1.49%, and 1.17% for the uninterrupted, mildly interrupted, and interrupted strategy, respectively; the WMI of TE complications was 0.16%, 0.46%, and 0.49% for the uninterrupted, mildly interrupted, and interrupted strategy, respectively, with no heterogeneity. OB appeared to be higher in uninterrupted (6.33%) and mildly interrupted (8.62%) groups compared with the interrupted (3.53%), with substantial heterogeneity among studies. No interaction was found between the incidence of MB and TE complications and different DOACs.

CONCLUSIONS

In patients undergoing PVI, these 3 anticoagulation strategies may have similar safety and efficacy in terms of MB and TE complications. OB appears to be higher in uninterrupted and mildly interrupted strategies compared with the interrupted strategy. No substantial differences were observed among DOACs regarding the incidence of MB and TE complications.

Influence of periprocedural anticoagulation strategies on complication rate and hospital stay in patients undergoing catheter ablation for persistent atrial fibrillation

BACKGROUND

The use of non-vitamin K antagonists (NOACs), uninterrupted (uVKA) and interrupted vitamin K antagonists (iVKA) are common periprocedural oral anticoagulation (OAC) strategies for atrial fibrillation (AF) ablation. Comparative data on complication rates resulting from OAC strategies for solely persistent AF (persAF) undergoing ablation are sparse. Thus, we sought to determine the impact of these OAC strategies on complication rates among patients with persAF undergoing catheter ablation.

METHODS

Consecutive patients undergoing persAF ablation were included. Depending on preprocedural OAC, three groups were defined: (1) NOACs (paused 48 h preablation), (2) uVKA, and (3) iVKA with heparin bridging. A combined complication endpoint (CCE) composed of bleeding and thromboembolic events was analyzed.

RESULTS

Between 2011 and 2014, 1440 persAF ablation procedures were performed in 1092 patients. NOACs were given in 441 procedures (31 %; rivaroxaban 57 %, dabigatran 33 %, and apixaban 10 %), uVKA in 488 (34 %), and iVKA in 511 (35 %). Adjusted CCE rates were 5.5 % [95 % confidence interval (CI) (3.1-7.8)] in group 1 (NOACs), 7.5 % [95 % CI (5.0-10.1)] in group 2 (uVKA), and 9.9 % [95 % CI (6.6-13.2)] in group 3. Compared to group 1, the combined complication risk was almost twice as high in group 3 [odd's ratio (OR) 1.9, 95 % CI (1.0-3.7), p = 0.049)]. The major complication rate was low (0.9 %). Bleeding complications, driven by minor groin complications, are more frequent than thromboembolic events (n = 112 vs. 1, p < 0.0001).

CONCLUSIONS

Patients undergoing persAF ablation with iVKA anticoagulation have an increased risk of complications compared to NOACs. Major complications, such as thromboembolic events, are generally rare and are exceeded by minor bleedings.

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.

Meta-Analysis of Efficacy and Safety of Apixaban in Patients Undergoing Catheter Ablation for Atrial Fibrillation

BACKGROUND

The efficacy and safety of apixaban in patients undergoing catheter ablation (CA) for atrial fibrillation (AF) are little investigated.

METHODS

The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and EMBASE were searched up to September 2015. Four literatures comparing apixaban with vitamin K antagonists (VKAs) were included. Data were pooled in Review Manager Software, using Mantel-Haenszel methods with a fixed-effects model. The funnel plots and Egger's test were used to examine publication bias. Heterogeneity was assessed using the I(2) test. Risk ratios (RR) and 95% confidence intervals (CI) of each study were calculated and pooled.

RESULTS

No significant differences were observed in rates of total bleeding (RR = 0.91, 95% CI [0.57, 1.46], I(2) = 0.0%), thromboembolic complications (RR = 0.75, 95% CI [0.03, 18.22], I(2) = 0.0%), or total events (RR = 0.90, 95% CI [0.56, 1.44], I(2) = 0.0%) between apixaban and VKAs group. The frequency of major bleeding was similar between apixaban and VKAs group (RR = 1.34, 95% CI [0.34, 5.30], I(2) = 0.0%).

CONCLUSION

Apixaban was as effective and safe as VKAs in the periprocedural period of CA.