Srivathsan, Komandoor

BACKGROUND: Pulsed field ablation is now widely used for atrial fibrillation (AF) ablation, but atrial tachyarrhythmia recurrence remains common and postablation risk tools are limited. We assessed whether a validated sinus‑rhythm artificial intelligence— enabled ECG AF probability score, and its early postablation change, predicts recurrence after pulsed field ablation. METHODS: We studied consecutive patients undergoing index pulsed field ablation across 3 Mayo Clinic sites (February 2024–March 2025) with ≥1 sinus‑rhythm ECG within 180 days preprocedure. Baseline artificial intelligence—enabled ECG AF score (range 0–1) was the mean across baseline ECGs. Recovery indices (RI30/60/90), defined as mean postprocedure artificial intelligence—enabled ECG score within days 1–30/60/90 minus baseline, predicted post‑blanking recurrence using corresponding 30‑, 60‑, and 90‑day blanking windows. The primary outcome was time to first documented AF/atrial flutter/atrial tachycardia episode >30 seconds, ascertained via clinic ECGs, ambulatory monitoring, and device interrogations. Cox regression adjusted for prespecified clinical and echocardiographic covariates assessed associations; Harrell C‑statistic quantified discrimination. RESULTS: Among 1052 patients (67±10 years; 33% women), median baseline score was 0.35; 320 (30%) recurred over 188 days. Higher baseline score independently predicted recurrence (hazard ratio per 0.1 increase, 1.08 [95% CI, 1.03–1.14]). Scores rose on day 0 after ablation, then declined over subsequent weeks, with persistently higher, less‑improving trajectories among patients who recurred (time×recurrence interaction P <0.001). Day 0 score was not independently associated with recurrence after adjustment. Attenuated early recovery (higher recovery index) was independently associated with recurrence, most robustly for RI-90 (hazard ratio per 0.1 increase, 1.15 [95% CI, 1.07–1.24]), and improved discrimination beyond baseline and covariates (C‑statistic, 0.63–0.67; ΔC=0.04). Findings were consistent in a historical thermal ablation cohort. CONCLUSIONS: Baseline and early postablation dynamics of a sinus‑rhythm artificial intelligence—enabled ECG AF probability score are associated with pulsed field ablation recurrence and may aid multivariable risk stratification; prospective validation is warranted.

ABSTRACT Background Pulsed field ablation (PFA) is an emerging non‐thermal ablation modality with proven safety in atrial arrhythmia ablation. However, data on its performance for ventricular arrhythmias (VA) remain limited. Objective To evaluate the feasibility, safety, and efficacy of PFA for complex VA in a multicenter real‐world US registry. Methods This retrospective study included consecutive patients undergoing PFA for ventricular tachycardia (VT) or premature ventricular contractions (PVCs) at three Mayo Clinic centers (April 2024 to July 2025). The primary feasibility outcome was the successful delivery of PFA lesions to the intended target substrate. Primary efficacy outcomes included acute procedural success; sustained VT recurrence requiring implantable cardioverter‐defibrillator (ICD) shocks or multiple antitachycardia pacing therapies; and ≥ 80% reduction in PVC burden. Safety outcomes included procedural complications, valvular function, thromboembolic events, renal function, and conduction disturbances. Results Twenty‐six patients were included (13 PVC, 13 VT). Acute success was achieved in all VT ablations (69.2% complete; 30.8% partial) and in 92.3% of PVC ablations. Complications occurred in 11.5% of patients (transient LBBB [ n = 1] and vascular complications [ n = 2]). No thromboembolic events, intracardiac thrombus, or acute kidney injury were observed. Lesions near the mitral valve apparatus did not worsen mitral regurgitation, including in patients with pre‐existing valve disease. After a median follow‐up of 365 days, one patient experienced VT recurrence requiring ICD shocks. Estimated recurrence‐free survival after VT ablation was 61.5% at 12 months; 58.3% of PVC patients achieved ≥ 80% burden reduction. Conclusion PFA for VA appears feasible and acutely effective, with a low rate of procedure‐related complications. While acute success was high, long‐term outcomes were acceptable for VT ablation and relatively modest for PVC ablation, highlighting the need for continued refinement of technology and energy‐delivery strategies. Larger prospective studies are warranted.

Abstract Aims Randomized trials comparing percutaneous left atrial appendage occlusion (LAAO) with oral anticoagulation (OAC) for stroke prevention in patients with atrial fibrillation have yielded conflicting results across device generations and anticoagulant eras. This Bayesian meta-analysis of randomized trials aimed to compare LAAO vs. OAC for stroke or systemic embolism (SSE) and non-procedural clinically relevant bleeding (CRB). Methods and results We conducted a systematic search across five databases (PubMed, Embase, Scopus, Web of Science, and Cochrane CENTRAL) to identify randomized trials of LAAO vs. OAC. Primary outcomes of stroke or systemic embolism, non-procedural CRB and clinical benefit composite were estimated using a Bayesian hierarchical random effects model and findings confirmed across robust sensitivity and subgroup analyses. Posterior probabilities for superiority, non-inferiority and equivalence were estimated using clinically meaningful margins. Six randomized trials including 7004 participants in the intention-to-treat groups, were analysed. LAAO was not associated with lower SSE vs. OAC (pooled RR, 1.11; 95% CrI, 0.80–1.49), with a 74.6% posterior probability of favouring OAC. The posterior probability of crossing non-inferiority was P(HR &lt; 1.4) of 89%. In contrast, LAAO reduced non-procedural CRB (pooled RR, 0.59; 95% CrI, 0.45–0.78). The net clinical benefit composite, pooling contemporary trials, demonstrated a pooled RR of 0.90 (95% CrI 0.51–1.50), with P(RR &lt; 1) of 76%, with substantial heterogeneity for this outcome. Conclusion This Bayesian meta-analysis found no clear evidence supporting clinically meaningful non-inferiority of LAAO over OAC for stroke prevention. Despite reduced non-procedural bleeding, LAAO did not demonstrate a similar reduction in major bleeding.

BACKGROUND: Catheter ablation for atrial fibrillation is a widely used rhythm-control strategy, yet its role in reducing thromboembolic risk and enabling oral anticoagulation (OAC) discontinuation remains uncertain. This meta-analysis aims to comprehensively synthesize and evaluate randomized controlled trial evidence supporting long-term antithrombotic strategies in patients with atrial fibrillation undergoing catheter ablation. METHODS: A systematic literature search was performed in MEDLINE/PubMed, Embase, and the Cochrane Central Register of Controlled Trials to identify randomized controlled trials evaluating antithrombotic strategies after catheter ablation for atrial fibrillation. The primary outcome was ischemic stroke. A frequentist network meta-analysis comparing reported treatment arms, along with a pooled incidence meta-analysis for outcomes of interest, was conducted. RESULTS: Four randomized controlled trials, including 3924 patients, met the inclusion criteria. Three trials compared long-term OAC continuation versus OAC discontinuation, and 1 compared OAC continuation with left atrial appendage occlusion after catheter ablation. No significant differences in stroke incidence were observed when comparing OAC or left atrial appendage occlusion with no antithrombotic therapy (incidence rate ratio, 0.90 [95% CI, 0.02–33.85]; P =0.95; incidence rate ratio, 0.79 [95% CI, 0.00–241.01]; P =0.94, respectively). Among patients who discontinued antithrombotic therapy without undergoing left atrial appendage occlusion (n=1161), with 2864 cumulative person-years of follow-up, the pooled incidence of stroke was 0.23 events per 100 person-years (95% CI, 0.02–2.43; I 2 =0%). CONCLUSIONS: This analysis reinforces that, across randomized data, the incidence of thromboembolic events in patients who discontinued OAC after successful ablation remained low. However, the evaluation of net clinical benefit is limited by the low number of events across all treatment arms, underscoring the need for larger studies with prolonged follow-up to further validate the safety of this strategy, particularly in higher-risk populations.

Abstract Aims The clinical significance of early recurrences during the blanking period following pulmonary vein isolation (PVI) remains uncertain, particularly after pulsed field ablation (PFA). This study aimed to evaluate the prognostic impact of early recurrences at 30-, 60-, and 90-day thresholds on outcomes following PFA for atrial fibrillation (AF). Methods and results Consecutive patients who underwent PFA for AF across multiple centres within the Mayo Clinic health system were included. The primary endpoint was AF-free survival. Kaplan–Meier and multivariate Cox regression analyses were performed to compare outcomes between patients with and without early recurrences using 30-, 60-, and 90-day thresholds. A total of 1162 patients were included. The estimated AF-free survival at 1 year was 70%. Early recurrences within 30-, 60-, and 90-days post-ablation were significantly associated with late recurrences beyond 90 days (hazard ratio [HR] 5.9, 95% confidence interval [CI] 4.4–7.9, P &lt; 0.01; HR 6.6, 95% CI: 5.0–8.6, P &lt; 0.01; and HR 9.1, 95% CI: 7.0–11.7, P &lt; 0.01, respectively). These findings remained significant among patients undergoing continuous rhythm monitoring. Early recurrences within 30 days in this subgroup were significantly associated with a 1-year AF burden &gt;1% or the need for repeat AF ablation (odds ratio 25.0, 95% CI: 6.6–126.8, P &lt; 0.01). Conclusion Early recurrences following PFA are strongly predictive of long-term arrhythmia recurrence and are unlikely to represent transient inflammatory phenomena. Accordingly, the applicability of the conventional blanking interval after PFA should be reconsidered.

BACKGROUND: Cavotricuspid isthmus (CTI) ablation is frequently performed either as a standalone procedure or in combination with pulmonary vein isolation. With the rapid adoption of pulsed field ablation for atrial fibrillation, it is essential to delineate the utility of this modality in treating CTI-dependent atrial flutter (AFL). This study aims to evaluate the procedural and clinical outcomes of CTI ablation using pulsed field energy. METHODS: We conducted a retrospective analysis of consecutive patients who underwent pulsed field ablation for CTI-dependent AFL between January 2024 and March 2025. The primary end points were acute procedural success, periprocedural complications, and CTI-dependent AFL recurrence during follow-up. RESULTS: A total of 132 patients underwent CTI nonthermal ablation. The median age was 69.5 years, and 27.3% were female. The Farawave catheter was used in 93.9% of cases, PulseSelect in 4.5%, and Sphere-9 in 1.5%. Acute block was achieved in 99.2% of patients, although 8 required adjunctive radiofrequency ablation to complete the line. Periprocedural complications included transient ST-segment elevation in 2 patients and transient conduction disturbances in 3. During a median follow-up of 114 days (n=131), 5 patients (3.8%) experienced recurrence of typical AFL. The 6-month typical AFL-free survival estimate was 93.6%. CONCLUSIONS: Pulsed field ablation appears to be a feasible and effective strategy for CTI-dependent AFL. However, anatomic variability may limit its universal applicability with current catheter designs. Although acute procedural success is high, the long-term durability of the CTI block and its comparative efficacy versus conventional thermal ablation remain areas requiring further investigation.

Abstract Aims Patients with end-stage renal disease (ESRD) and atrial fibrillation present a challenge for thromboembolic prevention, given their elevated risks of both thromboembolism and bleeding. Anticoagulants carry a higher bleeding risk in this population without clear evidence of thromboembolic benefit. This study aims to define the role of left atrial appendage occlusion (LAAO) as a preventive strategy for patients with ESRD. Methods and results A systematic literature review was conducted to identify studies reporting outcomes in patients with ESRD who underwent LAAO. Meta-analyses of aggregate and individual patient data were performed to evaluate acute and long-term outcomes and compare them with those of patients without ESRD. Seventeen studies reporting data from 24 127 patients, including 1047 with ESRD, were included. Procedural complications were more common in patients with ESRD (RR 2.23; P = 0.02), with a pooled rate of 4% (95% CI, 1–9%). There was no significant difference in thromboembolic event rates during follow-up between the groups (IRR 1.44; P = 0.16), but major bleeding incidence was higher among patients with ESRD (IRR 1.84; P &lt; 0.01). Individual patient-level data from seven studies comprising 4745 patients (268 with ESRD) were obtained and analysed. Similarly, there was no significant association between ESRD and stroke/TIA incidence (HR, 1.22; 95% CI, 0.66–2.26), but major bleeding was higher on patients with ESRD (HR, 1.65; 95% CI, 1.01–2.69). Conclusion LAAO represents a feasible option for thromboembolic prevention in patients with ESRD, although these patients have an increased risk of complications and bleeding.

ABSTRACT Introduction Atrial fibrillation (AF) is the most common arrhythmia, and atrioventricular (AV) node ablation with pacemaker implantation is a therapeutic option for refractory cases. However, AV node ablation in patients with bioprosthetic tricuspid valves poses technical challenges. Methods An 84‐year‐old male with an EVOQUE transcatheter tricuspid valve replacement underwent AV node ablation (AVNA) under intracardiac echocardiography (ICE) guidance. Results Successful AV block was achieved with precise catheter positioning, improving the patient's symptoms and ventricular rate control. Conclusion This case demonstrates the feasibility of AVNA in patients with tricuspid bioprostheses, demonstrating feasibility with ICE guidance.

Background: Recognition of the causes of early mortality after atrial fibrillation (AF) catheter ablation is essential for the improvement of patient safety. This study sought to determine the causes of early mortality (≤90 days) after AF ablation. Methods: We performed a retrospective analysis of AF ablation from January 1, 2013, to December 1, 2021 at the Mayo Clinic (Rochester, Phoenix, and Jacksonville). Causes of death were identified through a comprehensive chart review of the electronic health record from within the Mayo Clinic system and outside records when available. Results: A total of 6723 patients were included in the study. The 90-day all-cause mortality rate was 0.22% (n=15). Among all 90-day deaths, majority of the deaths (73.3%) did not have a direct relationship with the procedure. Sudden death was the most common cause of early death (20%), followed by peri-procedural stroke (13%), respiratory failure (13%), atrioesophageal fistula (13%), infection (7%), heart failure (7%), and traumatic brain injury (7%). The 90-day mortality rate directly due to AF ablation procedural complications was 0.06% (n=4). Conclusions: AF ablation procedure has a 90-day mortality of 0.22%, and the most common cause of early mortality was sudden death. The majority (73.3%) of early mortality was not directly associated with a procedural complication, and the mortality rate due to complications associated with the AF ablation procedure was low at 0.06%. Further studies are required to investigate causes and risk factors associated with sudden death in this patient population.