First clinical data on artificial intelligence-guided catheter ablation in long-standing persistent atrial fibrillation.

INTRODUCTION: Despite advanced ablation strategies and major technological improvements, treatment of persistent atrial fibrillation (AF) remains challenging and the underlying pathophysiology is not fully understood. This study analyzed the multiple procedure outcome and safety of catheter ablation of spatiotemporal dispersions (DISPERS) detected by artificial intelligence (AI)-guided software in patients with long-standing persistent AF. METHODS AND RESULTS: The Volta VX1 software was used for 50 consecutive patients undergoing catheter ablation for persistent AF. First, high-density mapping (78% biatrial) with a multipolar mapping catheter was performed. In addition to pulmonary vein isolation (PVI), ablation of DISPERS was performed aiming at homogenizing, dissecting, isolating, or connecting DISPERS areas to nonconducting anatomical structures. Follow-up contained regular visits at our outpatient clinic at 1, 3, 6, and 12 months including 7-day Holter electrocardiograms. Patients were mainly suffering from long-standing persistent AF (mean AF duration 50.30 ± 54.28 months). Following PVI, ablation of left atrial and right atrial DISPERS areas led to AF cycle length prolongation (mean of 162.0 ± 16.6 to 202.2 ± 21.6 ms after) and AF termination to atrial tachycardia (AT) or sinus rhythm (SR) in 12 patients (24%). No stroke or pericardial effusion occurred; major groin complications (pseudoaneurysm n = 1, atrioventricular fistula n = 1) were detected in two patients. After a blanking period of 6 weeks, recurrence of any atrial arrhythmia was documented in 26 patients (52%). The majority of patients presented with organized AT (n = 15) while AF was present in n = 9 patients and AT/AF was observed in n = 2 patients. Twenty-two patients underwent reablation. During a mean follow-up of 363.14 ± 187.42 days and after an average of 1.46 ± 0.68 procedures, 82% of patients remained in stable SR. CONCLUSION: DISPERS-guided ablation using machine learning software (the Volta VX1 software) in addition to PVI in long-standing persistent AF ablation resulted in high long-term success rates regarding AF and AT elimination. Most arrhythmia recurrences were reentrant AT. After a total of 1.46 ± 0.68 procedures, freedom from AF/AT was 82%. Despite prolonged procedure times complication rates were low. Randomized studies are necessary to evaluate long-term efficacy of dispersion-guided ablation using AI.

Early ablation leads to better outcome in patients < 55 years with persistent atrial fibrillation.

The question of optimal timing for catheter ablation of atrial fibrillation (AF) to achieve best outcomes remains a crucial clinical issue. As AF occurs less frequently in younger patients, data regarding Diagnosis-to-Ablation Time (DAT) is especially limited in patients under the age of 55 years with persistent AF. We therefore analyzed the temporal relationship between initial AF presentation and timing of catheter ablation in this cohort. We conducted a retrospective single-centre study of patients ≤ 55 years with persistent AF who underwent first-time catheter ablation at our center. The cohort was divided into patients that underwent catheter ablation after diagnosis of persistent AF within a DAT of ≤ 12 months and patients with a DAT of > 12 months. A total of 101 patients (median age 51 years; female n = 19 (18.8%)) with persistent AF were included. Ablation was performed within 12 months ("early DAT") in 51 patients and > 12 months ("late DAT") in 50 patients. Pulmonary vein isolation was performed using high-power short-duration (HPSD) radiofrequency ablation. Median DAT was 5 months (1-12 months) in the early ablation group and 36 months (13-240 months) in the late ablation group. The median follow-up was 11.3 months (0.03-37.1 months). The rate of any atrial arrhythmia recurrence after a 30-day blanking period was significantly lower in the early DAT group (13/51 patients; 25.5%) as compared to the late DAT group (26/50 patients; 52.0%) (log rank test; p = 0.003). Catheter ablation performed > 12 months after the initial AF diagnosis was an independent predictor for the occurrence of any atrial arrythmia (OR: 2.58; (95%-CI: 1.32-5.07). Early first-time catheter ablation (DAT ≤ 12 months) in patients ≤ 55 years with persistent AF is associated with a significantly lower rate of arrhythmia recurrence.

Focal pulsed field ablation in complex atrial tachycardia: First clinical experience and 1-year outcome.

BACKGROUND: Pulsed field ablation (PFA) has become increasingly important in the treatment of cardiac arrhythmias. In addition to single-shot devices mainly used for pulmonary vein isolation, focal PFA may provide a treatment option that increases the versatility of the technique. OBJECTIVE: The purpose of this study was to provide data on feasibility, safety, and long-term outcome of focal PFA for ablation of complex atrial tachycardia (AT). METHODS: All consecutive patients (n = 34) with complex AT treated at our department between 2022 and 2023 with a focal PFA system (CENTAURI™, Galvanize Therapeutics) were included. The majority of patients (32/34) previously had undergone at least 1 radiofrequency ablation. Established contact force-sensing catheters were used for PFA application in combination with a PFA generator. Pulsed electric field trains were conducted in a R-wave triggered manner. RESULTS: Acute procedural success was accomplished in all patients. PFA included creation of 51 linear lesions and (re)isolation of 12 pulmonary veins. Mean procedural duration was 102.7 ± 30.3 minutes, with left atrial dwell time of 75.0 ± 24.7 minutes. Mean fluoroscopy duration was 8.7 ± 5.3 minutes. No complications occurred. After mean follow-up of 340.9 ± 130.1 days, recurrence of any AT occurred in 15 patients (44.1%). During 9 reablations, 3 gaps in previously created linear lesions were detected; the majority of recurrences (n = 6) were not related to previous PFA lesion creation. CONCLUSION: Focal PFA of complex AT substrates was safe and efficient. Acute procedural success was 100%. After 1 year, the majority of patients were in sinus rhythm. A minority of recurrences was caused by insufficient PFA lesion creation.

Renal function and periprocedural complications in patients undergoing left atrial catheter ablation: A comparison between uninterrupted direct oral anticoagulants and phenprocoumon administration.

BACKGROUND: Data regarding uninterrupted oral anticoagulation in patients with chronic kidney disease (CKD) during catheter ablation for left atrial arrhythmias is limited. This study aimed to evaluate the safety and efficacy of periprocedural uninterrupted direct oral anticoagulants (DOAC) compared with uninterrupted phenprocoumon in patients with CKD undergoing left atrial catheter ablation. METHODS AND RESULTS: We conducted a retrospective single-center study of patients who underwent left atrial catheter ablation between 2016 and 2019 with underlying chronic kidney disease (glomerular filtration rate (GFR) between 15 and 45 ml/min). The primary objective of this study was to investigate whether direct oral anticoagulant (DOAC) therapy or warfarin presents a superior safety profile in patients with chronic kidney disease (CKD) undergoing left atrial catheter ablation. We compared periprocedural complications (arteriovenous fistula, aneurysm, significant hematoma (> 5 cm)) and/or bleeding (drop in hemoglobin of >2 g/dl, pericardial effusion, retroperitoneal bleeding, other bleeding, stroke) between patients receiving either uninterrupted DOAC or warfarin therapy. Secondary analysis included patient baseline characteristics as well as procedural data. A total of 188 patients (female n = 108 (57%), mean age 75.3 ± 8.1 years, mean GFR 36.8 ± 6 ml/min) were included in this study. Underlying arrhythmias were atrial fibrillation (n = 104, 55.3%) and atypical atrial flutter (n = 84, 44.7%). Of these, n = 132 patients (70%) were under a DOAC medication, and n = 56 (30%) were under phenprocoumon. Major groin complications including pseudoaneurysm and/or AV fistula occurred in 8.9% of patients in the phenprocoumon group vs. 11.3% of patients in the DOAC group, which was not statistically significant (p = 0.62). Incidence of cardiac tamponade (2.3% vs. 0%; p = 0.55) and stroke (0% vs. 0%) were low in both DOAC and phenprocoumon groups with similar post-procedural drops in hemoglobin levels (1.1±1 g/dl vs 1.1±0.9 g/dl; p = 0.71). CONCLUSION: The type of anticoagulation had no significant influence on bleeding or thromboembolic events as well as groin complications in this retrospective study. Despite observing an increased rate of groin complications, the uninterrupted use of DOAC or phenprocoumon during left atrial catheter ablation in patients with CKD appears to be feasible and effective.

Role of the Ambulatory Assessed Apnea-Hypopnea Index for Predicting Recurring Atrial Fibrillation After Ablation Therapy.

Catheter ablation is an effective treatment for atrial fibrillation (AF). Obstructive sleep apnea (OSA) is a known risk factor for recurrent AF. The apnea-hypopnea index (AHI) is a measurement tool to screen patients for OSA. We sought to evaluate if the ambulatory assessed AHI is associated with AF recurrence following AF catheter ablation. 187 patients with paroxysmal (n = 155) or early persistent (n = 32) AF presenting for catheter ablation were included in the study. AHI was determined prior to ablation using an ambulatory screening device. All patients underwent pulmonary vein isolation (PVI). In patients with early persistent AF (17%) additional ablation of complex fractionated atrial electrograms (CFAE) was performed. Clinical follow-up was available after 3 and 12 months including 7-day Holter-ECG. All 187 patients (60.3 ± 11.4 years, 64.2% male) completed the 3 months follow-up and 170 patients the 12 months follow-up. A pathological AHI ≥15 was found in 45/187 (24.1%) patients. Additional CFAE did not differ between patients with an AHI ≥15 and AHI <15 (p = 0.663). After 3 months, 12/41 (29.3%) patients with AHI ≥15 showed recurrent AF compared to 24/146 (16.4%) patients with AHI <15 (p = 0.066). After 12 months, AHI ≥15 was associated with a significant higher rate of AF recurrence of 47.4% (18/38) versus 26.5% (35/132) in patients with AHI <15 (p = 0.014). In the logistic regression analysis AHI ≥15 was an independent predictor of recurrent AF at 12 months (p = 0.011). In conclusion, ambulatory assessed AHI ≥15 is associated with increased risk for AF recurrence following catheter ablation. OSA screening should be performed in AF patients as it might influence catheter ablation success.