Long term comparisons of atrial fibrillation ablation outcomes with a cryo-balloon or laser-balloon: a propensity-matched analysis based on continuous rhythm monitoring

BACKGROUND

Cryoballoon (CB) and laser-balloon (LB) catheter ablation (CA) have been demonstrated to achieve durable and effective pulmonary vein isolation (PVI). Only one head-to-head comparison with an intermittent rhythm monitor strategy is currently available. Aim of this study was to compare acute and long-term outcomes of CB and LB atrial fibrillation ablation procedures, using a continuous rhythm monitoring strategy.

METHODS

This was a prospective two-arm non-randomized propensity-matched observational trial, comparing the outcomes of atrial fibrillation (AF) ablation using LB and CB techniques. To evaluate AF recurrences, an implantable cardiac monitor (ICM) was implanted prior to hospital discharge to detect atrial tachyarrhythmias (ATAs) recurrences.

RESULTS

110 propensity-matched patients undergoing AF ablation with a LB (n=55) or with a CB system (n=55) were enrolled (paroxysmal AF 57.3%). Procedural time (LB: 87 [73-104] vs CB 90 [70-130] min; p=0.264) and fluoroscopy time did not differ. No differences in ATAs recurrences were observed at 12-month (LB-30.9% vs CB-29.1% and LB-45.5% vs CB-38.2%; log-rank 0.539). As for AF burden, the 12-month median was 0 [0-1] vs 0 [0-3]% (p=0.127), in the LB and CB-group, respectively. When considering only PeAF patients, median 12-month ATAs burden was 26 [18.5-40.5] vs 29 [26-35] % for the LB and CB patients (p=0.919).

CONCLUSION

In a propensity-matched cohort undergoing AF ablation, arrhythmia outcomes assessed by continuous rhythm monitoring did not differ between LB and CB, with an overall low ATAs burden. The only predictor of recurrences was persistent AF. There was no difference in procedure or fluoroscopy time.

Second-generation laser balloon ablation for the treatment of atrial fibrillation assessed by continuous rhythm monitoring: the LIGHT-AF study

AIMS

Balloon-based technologies have been developed to simplify catheter ablation of atrial fibrillation (AF), to improve the clinical outcome of the procedure and to achieve durable pulmonary vein isolation (PVI). The objective of this study is to evaluate the safety and efficacy of second-generation laser balloon (LB2) ablation in the treatment of AF using a continuous cardiac rhythm monitoring strategy. Atrial tachyarrhythmias (ATas) recurrences were assessed with implantable cardiac monitors (ICMs) or devices.

METHODS AND RESULTS

All patients underwent LB2 ablation procedure. The primary endpoint was the first recurrence of any, >5.5 and >24 h duration ATas after the blanking period (90 days). In-hospital visits were performed at 3, 6, and 12 months. Seventy-three patients (68% male, mean age 59.8 ± 11.3) were included in the study. The average procedure, fluoroscopy, and laser ablation times were 81.5 ± 30.1, 21.5 ± 12.4, and 33.8 ± 9.7, respectively. All PVs were isolated using the LB2 with no need of touch-up using focal catheters. No major complications occurred during or after the procedures. The one-year freedom from recurrences was 66.9% (95% CI: 57.0-76.7%), 81.0% (69.5-88.5%), and 86.8% (76.1-92.9%) considering any, 5.5-h and 24-h cut-off duration, respectively. At 3, 6, and 12 months, any ATas was recorded in 22%, 32%, and 25% of patients, with a ≥5% arrhythmic burden documented in 4%, 5%, and 3%, respectively. Few patients reported AF-related symptoms (7%, 8%, and 5%).

CONCLUSION

LB2 ablation is a safe and effective procedure, showing a high freedom from recurrences and low arrhythmic burden as documented by a continuous rhythm monitoring strategy.

Cryoballoon ablation for paroxysmal atrial fibrillation: mid-term outcome evaluated by ECG monitoring with an implantable loop recorder

BACKGROUND

The success rate after cryoballoon ablation (CB-A) performed for paroxysmal atrial fibrillation (PAF) might be overestimated by traditional noninvasive monitoring techniques. The purpose of this study was to evaluate the mid-term outcome of CB-A in patients with PAF implanted with an implantable loop recorder (ILR) after the procedure.

METHODS

Between January 2017 and March 2019, all patients who underwent CB-A for PAF and who were subsequently implanted with an ILR were retrospectively included. All devices were equipped with remote monitoring. All ILR-documented atrial tachycardia (AT) or AF episodes ≥ 6 min were considered as recurrence; both true and false episodes were collected. A 3-month post-procedural blanking period (BP) was applied.

RESULTS

A total of 102 patients (77 men, mean age 60.6 ± 9.6 years) who underwent pulmonary vein isolation (PVI) by CB-A were included; mean time from first diagnosis of AF to PVI was 51.5 ± 46.9 months. Mean follow-up was 29.3 ± 8.1 months; at 12-month follow-up, the success rate was 65.7%, while at 2-year follow-up, freedom from AT/AF recurrences was achieved in 59.3% of the patients. In the follow-up, a total of 4987 ECG strips were analyzed; true-positive episodes were confirmed in 2026 cases (40.6%), whereas 2961 episodes (59.4%) were considered false-positive.

CONCLUSION

In patients with PAF implanted with an ILR, CB-A results in freedom from any AT/AF recurrence in 65.7% of patients at 12-month follow-up and in 59.3% of patients when evaluated at 2-year. Careful adjudication of all ILR-documented AF episodes is required to avoid misdiagnosis.

[Role of permanent pacing in the prevention and treatment of atrial fibrillation]

Atrial fibrillation onset is enhanced by the presence of sinus bradycardia and sinus pauses. Cardiac pacing, by avoiding them, may prevent tachyarrhythmias. The atrial-based modes of pacing (AAI or DDD) demonstrated to be superior to ventricular pacing mode (VVI) in terms of reduction of atrial fibrillation burden and thromboembolic consequences of the arrhythmia. Many pacing algorithms have been proposed to ensure the maximum percentage of atrial pacing and to avoid post-extrasystolic pauses, both conditions that are needed to reduce atrial fibrillation burden. Moreover, it has been demonstrated that the efficacy in preventing the arrhythmia is superior if the site of pacing is a critical site for interatrial conduction, like Bachmann bundle or the low interatrial septum at the level of Koch triangle. Finally, also early treatment of the arrhythmia by overdrive or high-frequency pacing may contribute to reduce recurrences. Guidelines that have been published in the last years confirm that atrial-based pacing is effective in preventing atrial fibrillation in sick sinus syndrome, whereas the usefulness of prevention algorithms, alternative sites of pacing and pacing therapies is still under debate and further studies are needed.

Effects of heart rate changes on arterial distensibility in humans

In rats, an increase in heart rate by pacing is accompanied by progressive large-artery stiffening. Whether this is also the case in humans is unknown. We enrolled 20 patients who were chronically implanted with a pacemaker because of atrioventricular block or sick sinus syndrome. Arterial distensibility was measured by an echo-tracking device. In 10 patients, the evaluation was performed on the radial artery by using continuous finger blood pressure measurements, whereas in the remaining 10 patients, the common carotid artery was studied with a semiautomatic measure of brachial artery blood pressure. Diastolic diameter, systodiastolic diameter change, and distensibility were obtained at baseline (heart rate 63+/-2 beats/min) and after atrial and ventricular sequential pacing at a heart rate of 90 and 110 beats/min. At baseline, the diameter was 7.8+/-0.3 mm in the carotid artery and 2.4+/-0.1 mm in the radial artery; the respective systodiastolic diameter change values were 375.4+/-31.0 and 55.9+/-9.0 (microm) and the distensibility values were 1.4+/-0.1 and 0.7+/-0.1 (1/mm Hg 10-3). Blood pressure and diameter were not significantly modified by increasing heart rate, which markedly modified systodiastolic diameter change and distensibility. In the radial artery, distensibility was reduced by 47% (P<0.05) at a heart rate of 90 beats/min with no further reduction at 110 beats/min. In the carotid artery, distensibility was reduced by 20% at a heart rate of 90 beats/min (P<0.05) with a further reduction at 110 beats/min (45%, P<0.05). These data provide the first evidence in humans that acute increases in heart rate markedly affect arterial distensibility and that this occurs in both large- and middle-size muscle arteries within the range of "normal" heart rate values.