Vemulapalli, Hema Srikanth

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 Background/Introduction Atrial fibrillation (AF) is a common finding in patients with wild-type TTR amyloidosis. AF ablation represents a cornerstone of rhythm control in this population; however, the role of pulsed field ablation (PFA) remains unclear. Purpose This study aimed to describe the safety and efficacy of PFA for the treatment of atrial fibrillation in patients with wild-type TTR amyloidosis. Methods We conducted a prospective data collection of consecutive patients who underwent PFA for AF and had a confirmed diagnosis of wild-type TTR amyloidosis. The study included three centres within a major US health system. All procedures were performed between May 2024 and May 2025. A standardised follow-up strategy was applied, including 48-hour Holter monitoring between 90 and 180 days after ablation. The primary safety endpoint was the occurrence of procedural complications. The primary efficacy outcomes were acute procedural success and AF-free survival at six months after a blanking period of 30 days. AF recurrence was defined as any electrocardiographically documented episode lasting more than 30 seconds. Results A total of 13 patients were included in the study. The mean age was 72.6 ± 4.8 years, and all patients were male. Three patients (23.1%) underwent an index "redo" ablation. Seven patients (53.8%) had paroxysmal atrial fibrillation (AF). The median CHA2DS2-VASc score was 3 [2, 4.5], with a mean ejection fraction of 50.4 ± 14.8% and a mean left atrial volume index of 47.6 ± 15.7 mL/m². Eleven patients underwent PFA with the pentaspline Farawave catheter, and two with the focal Sphere-9 catheter. Additional extra-pulmonary vein lesions were performed in 11 patients, including posterior wall ablation in ten patients, cavotricuspid isthmus ablation in five, and mitral isthmus ablation in four patients. The primary endpoint occurred in one patient (7.7%) who developed acute respiratory failure complicated by pulseless electrical activity (PEA) arrest. The patient was successfully resuscitated but required prolonged hospital admission. All patients achieved acute pulmonary vein isolation, and six-month atrial fibrillation-free survival was 54.4%. Conclusion In this multicentre experience, pulsed field ablation (PFA) in patients with cardiac amyloidosis was feasible and acutely safe; however, the mid-term efficacy was suboptimal, with a relatively low six-month arrhythmia-free survival despite complete acute pulmonary vein isolation. These findings suggest that the current PFA strategies may not provide durable rhythm control in this population, underscoring the need for tailored ablation approaches and further research to improve long-term outcomes in patients with cardiac amyloidosis and atrial fibrillation.Figure 1

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 < 0.01; HR 6.6, 95% CI: 5.0–8.6, P < 0.01; and HR 9.1, 95% CI: 7.0–11.7, P < 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 >1% or the need for repeat AF ablation (odds ratio 25.0, 95% CI: 6.6–126.8, P < 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 Background While radiofrequency ablation (RFA) and cryoablation (CBA) are established treatments for atrial fibrillation (AF), pulsed field ablation (PFA) offers potential benefits. This study compares PFA's procedural outcomes with RFA and CBA. Methods A PRISMA‐guided systematic review searched PubMed, Cochrane, Embase, and Scopus through September 2024. Studies comparing PFA to RFA or CBA in paroxysmal and persistent AF were included. Results From 1413 titles, 28 studies (7944 patients, 4–13 months follow‐up) met inclusion criteria. PFA showed lower recurrence versus RFA (RR = 0.85, p < 0.05) and CBA (RR = 0.81, p < 0.01). Procedure times were shorter versus RFA (‐46.39 min, p < 0.01) and CBA (‐9.26 min, p < 0.01). PFA had fewer complications than CBA (RR = 0.45, p < 0.01) and thermal ablation (RR = 0.55, p < 0.01), with similar rates to RFA (RR = 0.81, p = 0.25). Fluoroscopy times were higher. Conclusion Promising results with PFA suggest it as a viable alternative to thermal ablation.

Background: Pulsed Field Ablation (PFA) has gained widespread adoption for pulmonary vein isolation (PVI) due to its tissue selectivity and safety profile. However, its role in cavotricuspid isthmus (CTI) ablation for typical atrial flutter is less defined. This study compares CTI ablation using PFA versus radiofrequency ablation (RFA) in patients undergoing PVI exclusively with PFA. Research Question: We hypothesized that in patients undergoing PFA-based PVI, CTI ablation using PFA would reduce procedure and fluoroscopy times without increasing complication or flutter recurrence rates compared to RFA. Methods: We retrospectively analyzed patients who underwent CTI ablation with either PFA or RFA alongside PFA PVI between 2024 – 2025 across all Mayo Clinic sites. Baseline characteristics, procedural parameters, acute success, and 12-month arrhythmia recurrence were compared between groups. All patients received standard follow-up, including ECGs and Holter monitoring. Results: A total of 350 patients were included (CTI PFA: n = 126; CTI RFA: n = 224). Patients in the PFA group were older (68.8 ± 8.5 vs. 65.7 ± 10.1 years; p <0.01) and had higher CHA2DS2-VASc scores (2.84 ± 1.57 vs. 2.45 ± 1.45; p = 0.02). Fluoroscopy (18.9 ± 9.1 vs. 25.2 ± 23.3 min; p < 0.01 ) and procedure times (172.6 ± 22.4 vs. 224.7 ± 74.2 min; p < 0.01) were significantly lower in the PFA group. Complication rates (8.7% vs. 4.9%; p = 0.15) and typical flutter recurrence (3.1% vs. 1.7%; p = 0.46) were similar between groups during a mean follow-up of 125 days. Conclusion: In patients undergoing PVI with PFA, CTI ablation using PFA is associated with significantly reduced procedure and fluoroscopy times compared to RFA, without increased complications or arrhythmia recurrence. These findings support the feasibility and efficiency of PFA for typical flutter ablation when performed during PFA-based AF procedures.

Background: Pulsed field ablation (PFA) has become a cornerstone for atrial fibrillation ablation. Multiple platforms have been developed and approved worldwide, and routine screening for asymptomatic brain injury (ABI) has been included in several trials as part of the safety assessment of this technology. The incidence by catheter/platform, predictors of occurrence, and clinical impact remain incompletely understood. Research Question: In patients with atrial fibrillation undergoing pulmonary vein isolation, does the incidence of ABI vary between different PFA platforms? Methods: We searched the MEDLINE/PubMed, Embase, and Cochrane Central Register of Controlled Trials databases for studies reporting on patients who underwent PFA and post-procedure brain MRI to screen for ABI. The review was conducted in accordance with PRISMA guidelines. A random-effects proportion meta-analysis was performed, with subgroup analysis based on the PFA platform used. For studies including a thermal ablation control group, risk ratio (RR) was used to compare outcomes. Finally, a meta-regression was conducted to identify potential predictors of ABI incidence. Results: A total of 19 studies reporting data from 742 patients who underwent post-ablation brain MRI were included in this review. The pooled incidence of silent cerebral events (new findings visible only on DWI sequences) and silent cerebral lesions (new findings on both DWI and FLAIR sequences) was 5% each (95% CI, 3%–8%). The pooled incidence of any ABI was 10% (95% CI, 8%–13%). A platform-level subgroup analysis demonstrated comparable outcomes across the platforms with available data (Figure 1). The meta-regression included age, sex, CHA2DS2-VASc score, and incidence of symptomatic stroke/TIA, but no statistically significant associations were identified. In the four studies that included a thermal ablation control group, there was no significant difference in ABI incidence between PFA and thermal ablation (RR: 1.37; 95% CI, 0.68–2.74; P = 0.38; I2 = 16%) (Figure 2). Seven studies reported follow-up MRI in patients who presented with an ABI. Among 20 patients with ABI after ablation, radiologic lesions persisted in 2 patients. Conclusion: ABI is a relatively frequent finding following PFA; however, current evidence does not reveal significant differences between available platforms. Radiologic findings tend to be transient, suggesting a limited long-term clinical impact.

Background: A blanking period allowing for atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI) has historically been standardized to 90 days. With the recent introduction of pulsed field ablation (PFA) for PVI and emerging in vitro data suggesting a shorter inflammatory timeframe, it remains unclear whether recurrences during this 90-days period reflect incomplete procedural success or merely transient inflammatory changes. Research Question: In patients undergoing PVI with PFA, do early AF recurrences at 30, 60, and 90 days predict late AF recurrences beyond the standardized 90-day blanking period? Methods: Patients undergoing PFA for AF were retrospectively included. Procedures were performed under general anesthesia, and high-density (HD) mapping, with PVI and additional ablation lines applied at the operator’s discretion. PFA catheters included Farawave, PulseSelect, and Sphere-9. AF recurrences were defined as documented episodes on 12-lead ECG or cardiac monitoring devices, confirmed by interpretation from an experienced cardiologist. Survival analyses were conducted based on the occurrence of early recurrences at 30, 60, and 90 days post-ablation. Kaplan-Meier curves and hazard ratios were reported. This study was approved by our institutional review board. Results: To the best of our knowledge, this is the largest real-world study reporting outcomes of PFA for AF in the United States. A total of 1,214 patients were included in the analysis. Mean age was 66.4 years; 31.9% were female, and 22.4% underwent redo PVI. Six-month AF recurrence-free survival was 79% (95% CI, 75–83%) for the overall cohort. Patients experiencing early recurrence at 30, 60, and 90 days had a significantly higher risk of AF recurrence beyond the standardized 90-day blanking period (HR 4.0, 95% CI 2.7–5.9, P < 0.01; HR 5.0, 95% CI 3.6–7.1, P < 0.01; and HR 6.9, 95% CI 4.9–9.6, P < 0.01, respectively). Conclusion: Early recurrences at 30, 60, and 90 days post-ablation are strongly associated with atrial fibrillation recurrence beyond the 90-day blanking period. These findings challenge the traditional concept of blanking period after PFA and suggest that early recurrence may indicate incomplete procedural success rather than transient inflammation.

Background: Spontaneous coronary artery dissection (SCAD) is increasingly recognized as a cause of acute coronary syndrome, particularly in young to middle-aged women. While most presentations are associated with preserved left ventricular ejection fraction (LVEF), a subset of patients present with acute systolic dysfunction. The characteristics of patients who recover their LVEF are not clearly defined. Methods: We retrospectively analyzed 495 patients with angiographically confirmed SCAD treated at three Mayo Clinic sites (Arizona, Rochester, and Florida) from 1994 to 2023. Patients with a prior history of myocardial infarction, coronary artery disease, and congenital heart disease were excluded. Baseline LVEF at SCAD presentation was categorized into <35%, 35–39%, 40–49%, and ≥50%. Follow-up LVEF was assessed by echocardiography performed between 30 days and 1 year post-SCAD. The primary outcome was improvement in LVEF to ≥50% at follow-up. Results: A total of 495 SCAD patients were included. At presentation, 26% had reduced LVEF: 6% had LVEF <35%, 5% had LVEF between 35–39%, and 15% had LVEF between 40–49%. Patients who did not normalize their EF at follow-up were slightly younger (45 vs. 48 years, p=0.04), were more likely to have had an in-hospital cardiac arrest (13% vs. 4%, p=0.01), required mechanical circulatory support during their care, and had SCAD involving the left main artery (11% vs. 2%, p=0.01). Predictors of EF normalization included SCAD which involved the obtuse marginals (15% vs. 4%, p<0.05). The group with the lowest EF at presentation had the highest probability of persistent EF <50% at follow-up (32% for those with LVEF <35%) while patients who had normal EF at presentation had a 6% chance of having EF <50% at follow-up (Figure 1). Conclusions: Our study shows that the majority of SCAD patients have normal EF at presentation. 80% of those with reduced EF at presentation will normalize at follow-up. Predictors of low EF at follow-up included dissection involving the left main artery, lower EF at SCAD presentation, in-hospital arrest and use of mechanical circulatory support.