Impact of very wide antral pulmonary vein isolation on esophageal temperature changes during pulsed field ablation

Funding Acknowledgements

Type of funding sources: None.

Background

Esophageal thermal injury (ETI) is a serious drawback of available energy sources for atrial fibrillation (AF) ablation, especially on the posterior left atrial (LA) wall. Pulsed field ablation (PFA) is a novel non-thermal energy source with promising safety advantages over existing methods due to its unique myocardial tissue specificity sparing the esophagus.

Objective

To evaluate esophageal temperature changes during very wide antral pulmonary vein isolation (PVI) using the PFA system.

Methods

Thirteen consecutive AF patients (62% with paroxysmal AF; age: 61 years; 70% male) underwent first-time PFA under deep sedation. Eight pulse trains (2kV/2.5 sec, bipolar, biphasic, 4x basket/flower configuration each) were delivered to each pulmonary vein (PV). Extra pulse trains in the flower configuration were added for very wide antral circumferential ablation (vWACA). Continuous intraluminal esophageal temperature (TESO) was monitored with an S-shaped esophageal temperature probe.

Results

A median of 32 (IQR 32;32) and 8 (IQR 8;9) pulse trains for PVI and vWACA with a procedural time and catheter dwell time of 67 min (IQR 61-69) and 17 min (IQR 16-18) were applied. PFA with vWACA resulted in consecutive posterior LA wall isolation in 11/13 patients. Fluoroscopically, the esophagus coursed near the right PVs in 2/13, left PVs in 8/13 and mid-posterior wall position in 3/13 patients. Maximum TESO increase from baseline was 0.8 ±0.9 °C. However, no clinically relevant TESO changes occurred (Table 1). On short-term, all patients remained asymptomatic for sore throat, cough, or other symptoms potentially related to ETI. No esophago-duodenoscopy was necessary.

Conclusion

PFA of the PVs and lesion extension to the posterior LA wall demonstrated clinically non-significant TESO changes and has the potential to eliminate the risk of a thermal damage to the esophagus.

Very high-power short-duration temperature-controlled ablation for cavotricuspid isthmus block : the Fast-and-Furious CTI study

Funding Acknowledgements

Type of funding sources: None.

Background

Catheter ablation for typical right atrial flutter (AFL) provides an effective treatment associated with encouraging clinical outcome. The novel micro-electrode ablation catheter allows very high-power short-duration (vHP-SD, 90 W/4 sec) ablation and potentially offers the ability to perform a safe, effective and faster cavotricuspid isthmus (CTI) ablation.

Aims

We evaluated feasibility and efficacy of a vHP-SD (90 W/4 sec) temperature-controlled radiofrequency (RF) CTI ablation for AFL using a novel contact force (CF) sensing ablation catheter with micro-electrodes.

Methods

Fifteen consecutive patients (median age 75 years (interquartile range, IQR: 67, 79), 67 % male) with documented typical AFL were prospectively enrolled and underwent vHP-SD based CTI ablation (90 W/4 sec). Durability of CTI block was proven by pacing maneuvers from both sides of the ablation line.

Results

Complete CTI block using vHP-SD ablation was achieved in all patients (Figure 1). At median 23 (IQR 20; 39) RF applications over a median RF ablation time of 92 (IQR 78, 154) seconds were applied. It was not necessary to switch to the standard temperature-controlled mode to achieve durable CTI block. No periprocedural complications, no charring and no steam pops were observed.

Conclusions

Very high-power short-duration (90 W/4 sec) CTI ablation for the treatment of typical AFL is feasible and efficient. Effective CTI block can be achieved in about 1.5 minutes of RF time.

Comparison of ostial versus very wide antral circumferential pulmonary vein isolation using pulsed field ablation

Funding Acknowledgements

Type of funding sources: None.

Background

Pulmonary vein isolation (PVI) is the gold standard for first-time atrial fibrillation (AF) ablation procedures. Wide antral circumferential ablation (WACA) in comparison to ostial PVI has been attributed to an improved rhythm outcome after AF ablation. Pulsed field ablation (PFA) is a novel energy source with promising safety and efficacy advantages over existing ablation methods due to its unique myocardial tissue specificity. Feasibility of PFA for very WACA has not been investigated so far.

Objective

To evaluate procedural characteristics and lesion formation during wide antral circumferential PVI in comparison to ostial PVI using a PFA system.

Methods

Thirty-seven consecutive AF patients underwent first-time PFA under deep sedation. Patients eighter received ostial (ostial group; N = 15: 66 % paroxysmal AF; age: 69 years; 66 % male) or very wide antral (vWACA group; N = 22: 59 % paroxysmal AF; age: 62 years; 73 % male) PFA. Pre and post ablation LA voltage maps were acquired using a 20-pole spiral catheter together with a 3-dimensional electroanatomic mapping system (voltage cutoff ≤0.5 mV). On post ablation maps, lesion size by encircling the ablated area was measured. In all patients, 8 pulse trains (2kV/2.5 sec, bipolar, biphasic, 4x basket/flower configuration each) were delivered to each pulmonary vein (PV). In the vWACA-group, extra pulse trains in flower configuration were added to each PV in a wide antral position continuous intraluminal esophageal temperatures (TESO) were monitored with an S-shaped esophageal temperature probe.

Results

A median of 8 [IQR 8;8] and 10 [IQR 10;11] pulse trains per PV for ostial and vWACA PVI were applied. vWACA PFA resulted in significant larger lesion formation (47.3 cm2 [IQR 39.1; 52.0]) in comparison to ostial PFA (35.5 cm2 [IQR 30.3; 38.1], p=0.013) with consecutive posterior LA wall isolation in 19/22 (86 %) patients (Figure 1). In the vWACA group, median TESO increased by 0.7 °C (TESOmax 36.5 °C [IQR 36.0;36.9]). However, the vWACA approach was not associated with a significant increase in procedure time, sedation dosage or exposure to radiation.

Conclusion

Very wide antral circumferential PFA of the PVs is feasible and was associated with significant larger lesion formation in comparison to conventional ostial PFA. Concomitant posterior LA wall isolation occurred in the majority of patient and did not result in a clinically significant increase of intraluminal esophageal temperatures, procedure time, sedation and radiation dosage.

P1438Predictors and clinical impact of bleeding events after left atrial appendage closure in patients with high risk or a history of bleeding

Background

Left atrial appendage closure (LAAC) has emerged as an alternative to oral anticoagulation (OAC) for stroke prevention in patients with atrial fibrillation and may be especially attractive in patients with high risk or a history of bleeding. However, data of clinical benefit and incidence of post-procedural bleeding in patients with both high risk of bleeding and ischemic cerebral stroke after LAAC are lacking.

Objectives

This study sought to identify predictors and the prognostic impact of post-LAAC bleeding in patients at high risk and/or history of bleeding in the direct oral anticoagulant therapy (DOAC) era.

Methods and results

We retrospectively enrolled a total of 195 patients (75 ± 8.7 years, 38% female, 47% with previous major bleeding, mean CHA2DS2-VASc score 4.3 ± 1.6 and mean HAS-BLED score 2.7 ± 1.1) undergoing endocardial (91%) or epicardial (9%) LAAC during a mean follow-up of 339 ± 319 days. Twenty-three (11.9%) patients developed procedure-unrelated bleeding events after a median of 147 (43, 362) days after LAAC, in 12/23 (52%) patients under single antiplatelet therapy (SAPT), 6/23 (26%) dual antiplatelet therapy (DAPT), 1/23 (4%)  DOAC, 1/23 (4%) VKA, 2/23 (9%) dual therapy (SAPT and DOAC/VKA) and 1/23 (4%) triple therapy (DAPT and DOAC/VKA). (Figure) Diabetes mellitus and previous major bleeding were identified as the independent predictors of post-LAAC bleeding (Odds ratio 2.65 [95% CI:1.04-6.73], p = 0.041, and 5.50 [95% confidence interval:1.72-17.5], p = 0.004). Post-LAAC bleeding was associated with all-cause death (9/23 [39%] vs 18/171 [11%], p = 0.001), but not ischemic stroke/TIA (1/23 [4%] vs 6/171 [4%], p = 0.593) nor device thrombus (2/23 [9%] vs 3/171 [2%], p = 0.108). Kaplan-Meier curve estimated that patients with post-LAAC bleeding had a worse mortality than those without post-LAAC bleeding (3-year mortality; 35.6% [95%CI; 11.6-61.0%] vs 68.7% [45.0-83.8], p = 0.029)

Conclusions

In AF patients with high bleeding risk or history of bleeding undergoing LAAC, bleeding events are common and may occur even after long-term duration after LAAC. Previous major bleeding history strongly predicts subsequent bleeding events following LAAC and is associated with unfavorable mortality. Further investigations are required to identify optimal post-procedural antithrombotic strategies for patients undergoing LAAC with previous major bleeding.

Abstract Figure. The association between time to bleeding