Amin, Hina

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.

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.

Abstract Background Ventricular tachycardia (VT) is a life-threatening arrhythmia that can complicate structural heart disease. While catheter ablation is effective in treating this condition, the recurrence of VT after the procedure continues to be a concern. Consequently, there is a need for a reliable system to evaluate the likelihood of arrhythmia recurrence following an ablation. Objective To predict recurrence or repeat ablation after a VT catheter ablation procedure using machine learning (ML) models. Methods We conducted a single-center, retrospective study of all patients undergoing catheter ablation for scar-related VT between 2012 and 2022. Data collected included demographics, comorbidities, medications, relevant laboratory abnormalities, electrocardiograms, echocardiograms, detailed procedural characteristics, and outcomes. Python version 3.8.5 for exploratory data analysis (EDA) and visualization. Using six different ML models from the training set (90:10 split), we used 34 variables to predict the primary outcome, including VT recurrence or repeat catheter ablation. The accuracy of these models was compared using ROC curves based on their performance on the test set. Results Out of 508 VT ablation procedures, 261 experienced a recurrence. Support Vector Classifier (SVM) performed the best, having an AUC of 0.73, followed by logistic regression at 0.69 (Figure A). SVM yielded sensitivity, specificity, positive and negative predictive values of 0.73, 0.73, 0.79, and 0.67, respectively. The F1 score was 0.70. Among the factors with the highest feature importance in the model, the most influential variable was the proceduralist’s experience level, followed by QRS width at baseline, LVEF, and patient’s age (Figure B). Conclusion Our model can predict recurrent VT after ablation with reasonable accuracy, outperforming the existing clinical risk scores significantly. Larger training sample sizes will help achieve more robust ML models and improve predictive accuracy further.Figure A: ROC curve depicting the AUROCB. Feature importance graph

Background: Atrioventricular (AV) conduction ablation has been achieved by targeting the area of penetration of the conduction axis as defined by recording a His bundle potential. Ablation of the His bundle may reduce the possibility of a robust junctional escape rhythm. It was hypothesised that specific AV nodal ablation is feasible and safe. Methods: The anatomical position of the AV node in relation to the site of penetration of the conduction axis was identified as described in dissections and histological sections of human hearts. Radiofrequency (RF) ablation was accomplished based on the anatomical criteria. Results: Specific anatomical ablation of the AV node was attempted in 72 patients. Successful AV nodal ablation was accomplished in 63 patients (87.5%), following 60 minutes (IQR 50–70 minutes) of procedure time, 3.4 minutes (IQR 2.4–5.5 minutes) of fluoroscopy time, and delivery of 4 (IQR 3–6) RF lesions. Αn escape rhythm was present in 45 patients (71%), and the QRS complex was similar to that before ablation in all 45 patients. Atropine was administered in six patients after the 10-min waiting period and did not result in restoration of conduction. In nine patients, AV conduction could not be interrupted, and AV block was achieved with ablation of the His after delivery of 12 (IQR 8–15) RF lesions. No cases of sudden death were encountered, and all patients had persistent AV block during a median 10.5 months (IQR 5–14 months) of follow-up. Conclusion: Anatomical ablation of the AV node is feasible and safe, and results in an escape rhythm similar to that before ablation.

Abstract Introduction Transsubclavian venous implantation of the Aveir leadless cardiac pacemaker (LCP) has not been previously reported. Methods and Results Three cases of transsubclavian implantation of the Aveir LCP are reported. Two cases were postbilateral orthotopic lung transplant, without appropriate femoral or jugular access due to recent ECMO cannulation and jugular central venous catheters. In one case, there was strong patient preference for same‐day discharge. Stability testing confirmed adequate fixation and electrical testing confirmed stable parameters in all cases. All patients tolerated the procedure well without significant immediate complications. Conclusions We demonstrate the feasibility of transsubclavian implantation of the Aveir LCP.