Thromboembolic and bleeding risks in patients undergoing atrial fibrillation ablation: oral anticoagulation perspectives

Catheter ablation of atrial fibrillation: anticipating and avoiding complications

INTRODUCTION

Atrial fibrillation (AF) ablation is being performed more frequently and more widely at more centers. This stems from several factors including 1) demographic forces leading to an increased prevalence of the arrhythmia; 2) greater availability of ambulatory monitoring making diagnosis more frequent; 3) relative inefficacy of medications; and 4) improved safety and efficacy of the procedure. Ablation has become much more streamlined and reproducible than a decade ago, but life-threatening complications may still arise.

AREAS COVERED

This review will focus on awareness, avoidance, and early recognition and management of complications of AF ablation. This literature review is challenged by differing approaches to ablation of AF both within a center and between centers, the rapid improvement of technology making the outcomes associated with a therapeutic strategy begun a few years prior relatively obsolete, as well as the heterogeneity of the population being studied.

EXPERT OPINION

Newer technologies are on the horizon which will allow us to ablate AF with increasing efficacy, efficiency, and hopefully safety. Such new technology and changing usage mandate vigilance to avoid complications.

Effect of uninterrupted dabigatran or rivaroxaban on achieving ideal activated clotting time to heparin response during catheter ablation in patients with atrial fibrillation

BACKGROUND

Uninterrupted use of oral anticoagulants before atrial fibrillation (AF) ablation can reduce the incidence of perioperative thromboembolic events. However, the effect of new oral anticoagulants on activated clotting time (ACT) in response to heparin during AF ablation in Chinese populations remains unknown. The aim of the present retrospective study was to investigate the value of ACTs in response to intraoperative heparin administration in patients using dabigatran or rivaroxaban.

METHODS

From January 2018 to December 2021, a total of 173 patients undergoing AF ablation were included in the study, in which 101 patients were treated with dabigatran, 72 patients were treated with rivaroxaban. The intraoperative ACT values were examined in both groups. The incidence of periprocedural complications was evaluated.

RESULTS

Initial heparin dosage (88 ± 19 U/kg vs. 78 ± 27 U/kg, P < 0.05), total heparin dosage (137 ± 41 U/kg vs. 106 ± 52 U/kg, P < 0.05) during the ablation procedure were higher in the dabigatran group than those in the rivaroxaban group. Mean ACT (280 ± 36 s vs. 265 ± 30 s, P < 0.05), and the percentage of ACTs within the therapeutic range (250-350 s) (74% ± 26% vs. 60% ± 29%, P < 0.05) were significantly lower in the dabigatran group than those in the rivaroxaban group, particularly in male patients. Furthermore, the average time of achieving the target ACT (250-350 s) was also found longer in the dabigatran group (P < 0.05) as compared with the rivaroxaban group. No significant difference was found in the incidence of periprocedural complications between the two groups.

CONCLUSIONS

The anticoagulant effect of uninterrupted rivaroxaban therapy appears to be more stable and efficient than dabigatran administration during catheter ablation in patients with AF.

Outcomes of uninterrupted vs interrupted Periprocedural direct oral Anticoagulants in atrial Fibrillation ablation: A meta-analysis

BACKGROUND

Studies indicate that uninterrupted anticoagulation (UA) is superior to interrupted anticoagulation (IA) in the periprocedural period during catheter ablation of atrial fibrillation. Still IA is followed in many centers considering the bleeding risk. This meta-analysis compares interrupted and uninterrupted direct oral anticoagulation during catheter ablation of atrial fibrillation.

METHODS

A systematic search into PubMed, EMBASE, and the Cochrane databases was performed and five studies were selected that directly compared IA vs UA before ablation and reported procedural outcomes, embolic, and bleeding events. The primary outcome of the study was major adverse cerebro-cardiovascular events.

RESULTS

The meta-analysis included 840 patients with UA and 938 patients with IA. Median follow-up was 30 days. Activated clotting time (ACT) before first heparin bolus was significantly longer with UA (P = .006), whereas mean ACT was similar between the two groups (P = .19). Total heparin dose needed was significantly higher with IA (mean, ‒1.61; 95% CI, ‒2.67 to ‒0.55; P = .003). Mean procedure time did not vary between groups (P = .81). Overall complication rates were low, with similar major adverse cerebro-cardiovascular event (P = .40) and total bleeding (P = .55) rates between groups. Silent cerebral events (SCEs) were significantly more frequent with IA (log odds ratio, ‒0.90; 95% CI, ‒1.59 to ‒0.22; P < .01; I 2, 33%). Rates of major bleeding, minor bleeding, pericardial effusion, cardiac tamponade, and puncture complications were similar between groups.

CONCLUSIONS

UA during atrial fibrillation ablation has similar bleeding event rates, procedural times, and mean ACTs as IA, with fewer SCEs.

Changes in plasma concentrations of edoxaban and coagulation biomarkers according to thromboembolic risk and atrial fibrillation type in patients undergoing catheter ablation: Subanalysis of KYU-RABLE

BACKGROUND

Catheter ablation (CA) for atrial fibrillation (AF) can be associated with a risk of thromboembolism and bleeding. We recently demonstrated that uninterrupted edoxaban with one dose delayed on the CA procedural day is associated with a low risk of periprocedural complications. Previous reports have indicated that some specific subgroups of patients undergoing CA have an increased risk of bleeding and thromboembolic complications. This subanalysis of the KYU-RABLE study assessed the changes in plasma concentrations of edoxaban and coagulation biomarkers during the periprocedural period of CA in subgroups stratified by the risk of thromboembolism assessed by CHADS2 score (<2 or ≥2) and AF type (paroxysmal AF [PAF] or non-PAF).

METHODS

We evaluated changes in plasma concentrations of edoxaban and coagulation biomarkers (D-dimer and prothrombin fragment F1+2), by subgroup, during the periprocedural period of CA. Measurements were made prior to CA (procedure day).

RESULTS

This subanalysis evaluated data from 343 patients with CHADS2 score <2 and 134 patients with CHADS2 score ≥2, and from 280 patients with PAF and 197 patients with non-PAF. Plasma edoxaban concentration decreased with time on the day of CA, while plasma concentrations of coagulation biomarkers remained unchanged. No significant differences were observed according to CHADS2 score or type of AF.

CONCLUSIONS

The changes in plasma concentrations of edoxaban and coagulation biomarkers in each subgroup were similar to those of the whole analysis, regardless of the thromboembolic risk (CHADS2 <2 or ≥2) or AF type (PAF or non-PAF).

Coagulation and heparin requirements during ablation in patients under oral anticoagulant drugs

BACKGROUND

Anticoagulation during catheter ablation should be closely monitored with activated clotting time (ACT). However vitamin K antagonists (VKA) or direct oral anticoagulant drugs (DOAC) may act differently on ACT and on heparin needs. The aim of this study was to compare ACT and heparin requirements during catheter ablation under various oral anticoagulant drugs and in controls.

METHODS

Sixty consecutive patients referred for ablation were retrospectively included: group I (n = 15, VKA), group 2 (n = 15, uninterrupted rivaroxaban), group 3 (n = 15, uninterrupted apixaban), and group 4 (n = 15, controls). Heparin requirements and ACT were compared throughout the procedure.

RESULTS

Heparin requirements during the procedure were significantly lower in patients under VKA compared to DOAC, but similar between DOAC patients and controls.Activated clotting time values were significantly higher in patients under VKA compared to DOAC and similar in DOAC patients versus controls. Furthermore, anticoagulation control as evaluated by the number/proportion of ACT> 300 as well as the time passed over 300 seconds was significantly better in patients under VKA versus DOAC, without significant differences between DOAC and controls. Finally, the number of patients/ACT with excessive ACT values was significantly higher in VKA versus DOAC patients versus controls.There was no significant difference between rivaroxaban and apixaban for ACT or heparin dosing throughout the procedure.

CONCLUSION

Vitamin K antagonists allowed less heparin requirement despite reaching higher ACT values and more efficient anticoagulation control (with more excessive values) compared to patients under DOAC therapy and to controls. There was no difference in heparin requirements or ACT between DOAC patients and controls.

Updates in periprocedural management of direct oral anticoagulants

PURPOSE OF REVIEW

As the prevalence of patients on antithrombotics is increasing, anesthesiologists must have a firm understanding of these medications and considerations for their periprocedural management. This review details up-to-date periprocedural management of direct oral anticoagulants (DOACs).

RECENT FINDINGS

DOACs have favorable pharmacokinetics including quick onset of action and short half-lives. Periprocedural management of DOACs relies heavily on drug half-life as well as procedural risk of bleeding. Other than a few exceptions, the American College of Cardiologists generally recommends complete clearance of oral anticoagulants prior to high-risk bleeding procedures and partial clearance prior to low-risk bleeding procedures. Procedures with little to no clinical risk of bleeding can be performed without any drug interruption or during trough levels. Exceptions to periprocedural DOAC management pertain to electrophysiology procedures.

SUMMARY

With the exception of no clinically relevant bleeding risk or certain electrophysiology procedures, DOACs should be discontinued periprocedurally in accordance with bleeding risks and drug's half-life. Bridging is generally not recommended for DOACs.

[Prevention of thromboembolic and hemorrhagic events in patients with atrial fibrillation undergoing elective surgery]

OBJECTIVE

To compare incidence of thromboembolic and hemorrhagic complications in patients with atrial fibrillation (AF) undergoing elective surgery on different schemes of perioperative anticoagulant therapy (ACT).

MATERIAL AND METHODS

There were 86 patients (56 (65.1%) men and 30 (34.9%) women, mean age was 69 (64; 78) years) with non-valvular AF who underwent elective interventions. Forty (46.5%) patients underwent abdominal surgery, 34 (39.5%) - cardiovascular procedures, 12 (14.0%) patients underwent surgery for malignant diseases. We have analyzed incidence of thromboembolic and hemorrhagic events and compliance of perioperative ACT modes with current international guidelines.

RESULTS

Thromboembolic and hemorrhagic events developed in 14 (16.3%) patients. Thromboembolic complications were noted in 6 (7.0%) patients, hemorrhagic events - in 8 (9.3%) cases. Maximum complication rate was observed in case of bridge-therapy (n=12, 20.0%). Cancellation of ACT was followed by 2 (9.5%) complications, bridge-therapy - by 4 (6.7%) thromboembolic complications. Hemorrhagic events were 2 times more common in case of this therapy (n=8, 13.3%). It was found that ESC guidelines for perioperative ACT were applied in less than half of patients (41, 47.7% patients with AF undergoing elective surgery). Half of complications (8 out of 16) occurred if unapproved modes of ACT were used (including 7 cases of bridge-therapy was not necessary). The causes of these complications were inadequate assessment of perioperative risk of thromboembolic and hemorrhagic events; unreasonable administration of bridge therapy.

CONCLUSION

An unambiguous clinical effect of bridge therapy has not been confirmed in patients with high risk of thromboembolic complications. Cancer patients have higher risk of complications compared with others. These events occur mainly due to non-compliance with clinical guidelines and insufficient prevention of thromboembolic events.

Periprocedural Use of Oral Anticoagulation Therapy in Patients Undergoing Atrial Fibrillation Ablation

Atrial fibrillation (AF) is the most common sustained arrhythmia encountered in clinical practice today. For those who present with it, one of the most major risks associated with the condition is stroke. AF is associated with a fivefold increased risk of stroke and thromboembolism. Oral anticoagulation has been the cornerstone of stroke prevention in patients with AF. In some individuals who exhibit a higher risk of bleeding, other alternatives for stroke prevention have been sought, including the use of left atrial appendage occlusion devices and surgical exclusion of the left atrial appendage. Catheter ablation is an important treatment strategy in those patients for whom a rhythm control strategy has been selected. This article reviews some of the available anticoagulant drug options and their use prior to, during, and after catheter ablation.