Poddar, Aastha

Background: Papillary Muscle (PM) related ventricular arrhythmia ablation is associated with lower acute success and suboptimal long-term outcomes due to complex anatomy, variable arrhythmogenic sites and dynamic exit points. Objective: To evaluate clinical and procedural outcomes of patients undergoing PM vs non-PM ablation. Methods: A retrospective analysis of adults (≥18 years) undergoing PVC ablation at Mayo Clinic (2019–2024) matched PM PVC ablations to controls (1:2) using propensity scoring based on age, sex, comorbidities and baseline LVEF. Chi-square and t-tests compared baseline and procedural characteristics. Logistic regression estimated odds ratios for immediate procedural success, PVC burden reduction and LVEF improvement at 3 months. Results: Of the 720 ablations, 392 cases were included after propensity matching: 132 PM and 260 non-PM. Patients in the PM group exhibited higher rates of complicated diabetes (9.8% vs 4.6%, p =0.045) and prior MI (18.2% vs 9.2%, p =0.011). Preprocedural ECG PVCs in the PM group showed a shorter intrinsicoid deflection (89.1 ± 35.0 msec vs 100.7 ± 24.3 msec, p <0.001) and longer coupling intervals (532.7 ± 100.3 vs 512.2 ± 81.4 msec, p =0.048).Moderate-to-severe MR was more prevalent in the PM group (17.4% vs 10.0%, p =0.036). Intraoperatively, the PM group had higher total energy delivery times (1939 ± 1336 sec vs 1227 ± 1033 sec, p <0.001) and more frequent cryoablation use (46.2% vs 7.3%, p <0.001). During post-ablation testing, non-clinical PVC was inducible in 39.5% of the cases in PM group compared to 25.7% in non-PM group ( p =0.005). More patients in the PM group were discharged on atleast one antiarrhythmic drug (AAD)(35.9% vs 18.5%, p <0.001) and AAD use persisted at 3 months (31.3% vs 18.4%, p =0.004). Outcomes were similar between groups, with no significant differences observed in immediate ablation success (aOR 0.64, p = 0.063, CI = 0.40-1.03), or >5% improvement in LVEF (aOR 0.76, p = 0.29) and PVC burden reduction (aOR 0.93, p = 0.81) at 3 months follow up. Conclusion: Patients undergoing PM ablation exhibited higher baseline rates of comorbidities. Intraoperatively they required greater energy delivery times, and an increased use of cryoablation. Postoperatively, a larger proportion of PM ablation patients required antiarrhythmic drug therapy. Despite these complexities, PM ablation showed no significant differences in PVC burden reduction, LVEF improvement, or procedural success compared to non-PM ablation.

Background: Catheter ablation of frequent premature ventricular complexes (PVCs) has been demonstrated to improve left ventricular ejection fraction (LVEF) in patients with PVC-induced cardiomyopathy. However, this improvement is not uniformly observed across all patients. Objective: To identify predictors of LVEF improvement following catheter ablation. Methods: This retrospective analysis included adult patients (≥18 years) who underwent PVC catheter ablation at Mayo Clinic, Rochester, between 2021 and 2024. Patients were grouped based on whether they experienced an LVEF improvement of ≥5%. Data on baseline comorbidities,, ECG characteristics, baseline transthoracic echocardiography (TTE), procedural details, and follow-up outcomes at 3-6 months (via Holter monitoring and TTE) were collected. Propensity matching (1:1) was performed using age(caliper=5), sex, and baseline LVEF(caliper=5). Comparative analyses used chi-square and t-tests. Variables with a p-value <0.1 were included in multivariate regression analysis. Results: After propensity matching, 98 patients with LVEF improvement and 98 controls were included. Table 1 summarizes baseline and procedural characteristics, and outcomes. Immediate PVC suppression was more common in the EF improvement group (74.2% vs. 60.4%, p=0.04), and fewer patients in this group were placed on long-term anti-arrhythmic medications (11.2% vs. 27.8%, p<0.01). Multivariate analysis showed that patients without PVC-related symptoms (OR=3.16, p=0.038) had higher odds of LVEF improvement, while those with CKD (OR=0.36, p=0.007) or a coupling interval ≥500 ms (OR=0.38, p=0.002) had lower odds of improvement.

Background: Patients with adult congenital heart disease (ACHD) form a unique subset of patients with complex ventricular tachycardia (VT). Objective: To evaluate the clinical and procedural characteristics and outcomes of patients with congenital heart disease who present for VT ablation. Methods: A single-center, retrospective study of patients undergoing VT ablation was conducted. The primary composite outcome was recurrent monomorphic VT, and repeat ablation. Results: Out of 508 procedures for ventricular tachycardia ablation, 37 were performed in ACHD patients. These patients were younger compared to the non-ACHD subtype.(Table 1). Out of 26 patients with congenital heart disease, a majority had a diagnosis of tetralogy of Fallot (57.6%) and 69% had 2-3 prior open-heart surgeries, including ventriculotomy (53.8%), ventricular septal defect repair (65.3%), and pulmonary valve replacement (57.6%) (Table2). They had a higher mean LVEF,and lower burden of comorbidities including hypertension, chronic kidney disease, and myocardial infarction compared to their non-ACHD counterparts and had been on fewer antiarrhythmics at baseline. ACHD patients were less likely to require epicardial access, but the requirement for induction meds was higher, and energy delivery times were longer. There were no significant differences in the VT characteristics and mapping techniques between the two groups. There were no significant differences in outcomes including complications, and time to recurrence, and a Kaplan-Meier analysis showed no significant difference in VT free survival when ACHD patients were compared to patients without ACHD (Figure 3). After adjusting for age, sex and comorbidities, ACHD was not a predictor of having VT recurrence or repeat ablation (aHR =1.1 (0.7-1.9), p=0.6) Conclusion: VT ablation in patients with ACHD is safe, and as effective as ablation in non-ACHD patients. Procedure times tend to be longer owing to a more challenging substrate.

Background: PAINESD score was established as a predictor of periprocedural acute hemodynamic instability, long-term mortality and heart failure among patients undergoing catheter ablation for ventricular tachycardia (VT-CA). Objective: To assess the validity of PAINESD score and compare outcomes of high-risk patients undergoing catheter ablation for ventricular tachycardia (VT) with and without mechanical circulatory support (MCS) use during procedure. Methods: We conducted an observational dual-center study of consecutive patients with SHD undergoing VT-CA over a decade (2012-2022). The PAINESD score, based on 7 variables (COPD, age >60 years, general anesthesia, ischemic cardiomyopathy, NYHA class III or IV, ejection fraction <25%, VT storm, and diabetes mellitus), was calculated and categorized into low risk (<10), intermediate risk (10-16), and high risk (>16) as previously reported. Two survival analyses were performed to compare outcomes between different groups: one using all-cause mortality or heart transplant as the event, and another using recurrent or repeat ablation as the event. Multivariable Cox proportional hazards regression models were used to calculate hazard ratios for each PAINESD category and to determine the hazard ratio for the use of MCS among high-risk patients. Results: We found that between 2012 to 2022, 559 ablations were performed on 441 patients. There were 296 (53%), 182 (32.6%) and 81(14.5%) patients in low, medium, and high risk. Using low risk as reference, aHR for medium risk was 2.1 (1.24-3.7; p=0.006) and for high risk was 4.6(2.54-8.3; p <0.001). Among patients with high PAINESD score (n=81), 5 patients (6.2%) required MCS (Intra-arterial balloon pump (IABP)=1, ECMO only=1, ECMO+IABP=1, bypass=2). 4/5 (80%) patients on MCS stayed on them post procedure, except one patient on IABP. In this cohort, there was no difference between patients with and without MCS in primary outcome [aHR= 1.6 (0.48-5.4); p=0.43] and in secondary OUTCOME [1.29 (0.3-5.5; p=0.735)]. Conclusion: PAINESD was a significant predictor of mortality or heart failure, but it did not help in prediction of recurrence of VT, or repeat VT-CA.

Background: Patients undergoing epicardial access for ventricular tachycardia (VT) have a higher rate of complications and VT recurrence post-procedure. Data regarding electrophysiological factors driving the outcomes are scant. Objective: To compare the factors and outcomes associated with epicardial vs endocardial VT ablation. Methods: A single-center, retrospective study of patients undergoing catheter ablation for scar-related VT was conducted. Data collected included demographics, comorbidities, medications, relevant laboratory abnormalities, electrocardiograms, echocardiograms, detailed procedural characteristics, and outcomes. Results: Our cohort of 554 patients had 89 (16.1%) epicardial and 465 (83.9%) endocardial VT ablations. Patients undergoing epicardial ablation had a greater frequency of NICM, and more patients had undergone sympathetic modulation for VT (p < 0.05) but had lesser frequency of valve surgery, and CABG. Epicardial ablation was associated with greater use of both short-term (<3 months) and long-term (>6 months) anti-arrhythmic drugs (AAD) (p<0.01). Epicardial access was obtained by micropuncture or needle-in-needle technique for 22.5% (n=20) of patients. Except for more use of general anesthesia and the lesser usage of drugs for VT induction during epicardial procedures, there were no significant differences. Epicardial ablation had a higher risk of acute complications (<30 days) after the procedure (driven by pericarditis) (25% vs 7.8%, p<0.01). On survival analysis, epicardial access was associated with an increase in VT recurrence and repeat ablation (p<0.01) during a mean follow-up of 1072 days. On multivariate analysis, after adjusting for age, sex and comorbidities, epicardial access was an independent predictor of VT recurrence or repeat ablation [aHR 1.61 (CI: 1.18- 2.2)] Conclusion: Patients undergoing epicardial ablations with fewer comorbidities demonstrated increased AAD usage prior to and after the procedure, and a higher risk of acute complications after the procedure. Epicardial access was an independent predictor of VT recurrence or repeat ablation.

Introduction: Ebstein's anomaly (EA) is associated with ECG signature of right bundle branch block (RBBB). Patients with EA also have high incidence of accessory pathways (AP) and it has been hypothesized that the absence of RBBB on ECG may be associated with a higher prevalence of AP. This study aims to assess the prevalence of RBBB in patients with EA and examine the correlation between its absence and the presence of AP. Methods: Adults (age>18 years) with EA, identified using the Mayo Adult Congenital Heart Disease registry, were divided into 3 groups based on the QRS morphology of their first ECG. Those with prior AP ablation were excluded. The demographic characteristics, baseline ECG data, echocardiographic parameters and EP study data were retrospectively collected and compared between the three groups using Chi-square or ANOVA test as appropriate. Results: Of 596 patients with EA, 358(60.06%) patients had a RBBB, bifascicular block or an incomplete RBBB (group1) ; 18 (3.02%) patients had either a LBBB , ventricular pre-excitation, isolated left anterior or posterior fascicular block (group 2); and 220 (36.92%) patients had normal QRS (group 3). The characteristics of these groups are compared in the table. Patients with RBBB had larger RV size, reduced RV systolic function and higher likelihood of tricuspid valve surgery. EP study was performed in 51 (14%), 3 (17%) and 51 (23%) patients in groups 1, 2,and 3 respectively. One or more APs were noted in 11/51 (22%) and 14/51 (30%) patients with RBBB and normal QRS respectively (p=0.18). Additionally, in patients who did not undergo an EP study, supraventricular tachycardia was documented in 39/307 (13%), 2/15(13%) and 13/169 patients (8%) in group 1,2 and 3 respectively during followup . Conclusion: In a large cohort of adults with EA in a tertiary referral center, greater than one-third of patients had a normal QRS complex without RBBB. However, EP study did not reveal a significant difference in the prevalence of accessory pathways between patients with and without RBBB. In EA, the absence of RBBB may not increase the risk of an underlying accessory pathway.

Background: In recent years, catheter ablation has emerged as a sustainable, first-line therapy for the management of ventricular tachycardia (VT). Given the rise of the “obesity paradox” theory in atrial ablation outcomes, we sought to study the effect of BMI on patients undergoing structural VT ablation. Purpose: To assess the outcomes of VT ablation, specifically VT recurrence, in patients with elevated vs. normal BMI. Methods: Clinical characteristics and demographic data were collected for VT patients who underwent ablation at Mayo Clinic Rochester from 2012-2022. Patient BMI was classified as non-obese (<30 kg/m2), obese (30-40 kg/m2), and morbidly obese (≥40 kg/m2). The endpoint was a composite of initial monomorphic VT recurrence and repeat ablation after adjusting for age, sex, and comorbidities. Results: A total of 399 patients underwent 508 ablations. 51.4% of ablations had a BMI <30, 39.2% were between 30-40, and 9.4% were ≥40. There was a greater prevalence of hypertension and type 2 diabetes mellitus in morbidly obese patients (p <0.01). Morbidly obese individuals also had a significantly increased rate of general anesthesia during ablation and long VT cycle lengths. The Kaplan-Meier curve demonstrates no statistically significant differences in time to VT recurrence among the three BMI groups (p = 0.324). Neither morbid-obesity (aHR= 1.20; CI = 0.94-1.56, p = 0.14) nor nonmorbid-obesity (aHR = 0.92; CI = 0.76-1.10, p = 0.4), compared to non-obesity was a significant independent predictor of VT recurrence or repeat ablation on multivariate regression after adjusting for age, sex and comorbidities. Conclusion: There was no significant association between BMI groups and VT recurrence or repeat ablation, and no difference in complications. We did not find the obesity paradox to be relevant for VT ablation in our patient population. Further study would be needed with larger samples to corroborate these findings.