Effects of cryoablation and radiofrequency ablation on endothelial and blood clotting activation

Right coronary artery compromise following radiofrequency catheter ablation for supraventricular tachycardia: cases reports

Background

Coronary compromise is a serious potential complication following catheter ablation; however, procedural details in the literature are often lacking, preventing the identification of learning opportunities.

Case summary

We report two cases of right coronary compromise following catheter ablation for symptomatic supraventricular tachycardia. After radiofrequency energy delivery at the coronary sinus ostium in both cases, inferior lead ST-elevation was observed. Diagnostic coronary angiography identified an occluded posterior left ventricular branch of the coronary artery, and optical coherence tomography demonstrated a high thrombus burden at this location. Electrocardiographic ST-segments settled with implantation of a drug-eluting stent.

Discussion

Coronary compromise was likely secondary to energy delivery during catheter ablation. This case series highlights the need for electrophysiologist to understand coronary anatomy relative to anatomical landmarks, to anticipate the risk of vascular injury as physical distance from the site of ablation is likely important. Risk for coronary compromise, while a rare complication, needs to be discussed with patients during the consenting process. We also demonstrate the importance of an efficient multi-disciplinary team process for managing acute procedural complications.

Efficacy and safety of uninterrupted low-intensity warfarin for cryoballoon ablation of atrial fibrillation in the elderly: A pilot study

WHAT IS KNOWN AND OBJECTIVE

Uninterrupted warfarin during cryoballoon ablation (CB-A) of atrial fibrillation (AF) has been widely accepted. However, to our knowledge, no previous studies exist investigating the optimal intensity of anticoagulation with warfarin for CB-A. This study aimed to evaluate the efficacy and safety of uninterrupted low-intensity warfarin for CB-A of AF in the elderly.

METHODS

Paroxysmal AF patients (age ≥ 70 years) who underwent CB-A were enrolled prospectively. The participants were stratified into 2 groups based on international normalized ratio (INR) before ablation (INR in group A: 1.5 to 2.0; INR in group B: 2.0-2.5). Primary endpoints included periprocedural thromboembolic complications and major bleeding. Secondary endpoints were new asymptomatic cerebral emboli (ACE) and minor bleeding.

RESULTS AND DISCUSSION

A total of 144 patients were enrolled (group A: 65; group B: 79). In group A, the use of concomitant antiplatelet drugs was more common. Also, the mean HAS-BLED score was significantly higher (2.4 ± 0.8 vs 2.0 ± 0.6, P < .01) and the mean activated clotting time (ACT) during the procedure was significantly lower (302 ± 14 s vs 311 ± 11 s, P < .01). Other clinical characteristics were balanced between the 2 groups. No thromboembolic complications and major bleeding occurred in either group. The incidence of periprocedural ACE was comparable between the 2 groups (9.2% vs 6.3%, P = .74). The incidence of minor bleeding in group A and group B was 4.6% and 11.4%, respectively (P = .14).

WHAT IS NEW AND CONCLUSION

Compared with standard-intensity warfarin, uninterrupted low-intensity warfarin might not increase the incidence of thromboembolic complications and might be associated with less bleeding risk during the perioperative period of cryoballoon ablation in the elderly. Large trials are needed to confirm these results.

Efficacy and Safety of Uninterrupted Low-Intensity Warfarin for Radiofrequency Catheter Ablation of Atrial Fibrillation in the Elderly

Background: No previous studies exist investigating the optimal intensity of uninterrupted anticoagulation with warfarin during radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) in the elderly. Objective: Evaluate the efficacy and safety of continuous low-intensity warfarin therapy throughout the periprocedural period of RFCA for AF in the elderly. Methods: This is a prospective randomized study. We enrolled AF patients (age ≥ 70 years) who underwent first-time RFCA for AF. Enrolled patients were randomized to group A and group B. The international normalized ratios before ablation were maintained at 1.5 to 2.0 and 2.0 to 2.5 in group A and B, respectively. Primary end points were periprocedural thromboembolic complications and major bleeding. Secondary end points included periprocedural asymptomatic cerebral emboli (ACE) and minor bleeding. Results: A total of 101 patients were enrolled in our study (group A: 52; group B: 49). Baseline characteristics were well balanced between the 2 groups. Only 1 patient suffered from stroke in group B. No major bleeding events occurred in either group. The incidence of new ACE lesions was comparable between the 2 groups (11.5% vs 8.2%, P = 0.82). Minor bleeding occurred in 1 of 52 (1.9%) patients in group A and in 5 of 49 (10.2%) patients in group B ( P = 0.10). Conclusions: Uninterrupted low-intensity warfarin for RFCA of AF might be as effective as standard-intensity warfarin in preventing periprocedural thromboembolic complications and might be associated with fewer bleeding events in the elderly.