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BackgroundSeveral distinct risk factors for arrhythmia recurrence and mortality following ventricular tachycardia (VT) ablation have been described. The effect of concurrent risk factors has not been assessed so far; thus, it is not yet possible to estimate these risks for a patient with several comorbidities. The aim of the study was to identify specific risk groups for mortality and VT recurrence using the Survival Tree (ST) analysis method.MethodsIn 1251 patients 16 demographic, clinical and procedure-related variables were evaluated as potential prognostic factors using ST analysis using a recursive partitioning algorithm that searches for relationships among variables. Survival time and time to VT recurrence in groups derived from ST analysis were compared by a log-rank test. A random forest analysis was then run to extract a variable importance index and internally validate the ST models.ResultsLeft ventricular ejection fraction, implantable cardioverter defibrillator/cardiac resynchronization device, previous ablation were, in hierarchical order, identified by ST analysis as best predictors of VT recurrence, while left ventricular ejection fraction, previous ablation, Electrical storm were identified as best predictors of mortality. Three groups with significantly different survival rates were identified. Among the high-risk group, 65.0% patients were survived and 52.1% patients were free from VT recurrence; within the medium- and low-risk groups, 84.0% and 97.2% patients survived, 72.4% and 88.4% were free from VT recurrence, respectively.ConclusionsOur study is the first to derive and validate a decisional model that provides estimates of VT recurrence and mortality with an effective classification tree. Preprocedure risk stratification could help optimize periprocedural and postprocedural care.

ObjectivesThis study sought to characterize ventricular tachycardia (VT) ablation outcomes across nonischemic cardiomyopathy (NICM) etiologies and adjust these outcomes by patient-related comorbidities that could explain differences in arrhythmia recurrence rates.BackgroundOutcomes of catheter ablation of VT in patients with NICM could be related to etiology of NICM.MethodsData from 2,075 patients with structural heart disease referred for catheter ablation of VT from 12 international centers was retrospectively analyzed. Patient characteristics and outcomes were noted for the 6 most common NICM etiologies. Multivariable Cox proportional hazards modeling was used to adjust for potential confounders.ResultsOf 780 NICM patients (57 ± 14 years of age, 18% women, left ventricular ejection fraction 37 ± 13%), underlying prevalence was 66% for dilated idiopathic cardiomyopathy (DICM), 13% for arrhythmogenic right ventricular cardiomyopathy (ARVC), 6% for valvular cardiomyopathy, 6% for myocarditis, 4% for hypertrophic cardiomyopathy, and 3% for sarcoidosis. One-year freedom from VT was 69%, and freedom from VT, heart transplantation, and death was 62%. On unadjusted competing risk analysis, VT ablation in ARVC demonstrated superior VT-free survival (82%) versus DICM (p ≤ 0.01). Valvular cardiomyopathy had the poorest unadjusted VT-free survival, at 47% (p < 0.01). After adjusting for comorbidities, including age, heart failure severity, ejection fraction, prior ablation, and antiarrhythmic medication use, myocarditis, ARVC, and DICM demonstrated similar outcomes, whereas hypertrophic cardiomyopathy, valvular cardiomyopathy, and sarcoidosis had the highest risk of VT recurrence.ConclusionsCatheter ablation of VT in NICM is effective. Etiology of NICM is a significant predictor of outcomes, with ARVC, myocarditis, and DICM having similar but superior outcomes to hypertrophic cardiomyopathy, valvular cardiomyopathy, and sarcoidosis, after adjusting for potential covariates.

BackgroundThe impact of catheter ablation of ventricular tachycardia (VT) on all-cause mortality remains unknown.ObjectiveThe purpose of this study was to examine the association between VT recurrence after ablation and survival in patients with scar-related VT.MethodsAnalysis of 2061 patients with structural heart disease referred for catheter ablation of scar-related VT from 12 international centers was performed. Data on clinical and procedural variables, VT recurrence, and mortality were analyzed. Kaplan-Meier analysis was used to estimate freedom from recurrent VT, transplant, and death. Cox proportional hazards frailty models were used to analyze the effect of risk factors on VT recurrence and mortality.ResultsOne-year freedom from VT recurrence was 70% (72% in ischemic and 68% in nonischemic cardiomyopathy). Fifty-seven patients (3%) underwent cardiac transplantation, and 216 (10%) died during follow-up. At 1 year, the estimated rate of transplant and/or mortality was 15% (same for ischemic and nonischemic cardiomyopathy). Transplant-free survival was significantly higher in patients without VT recurrence than in those with recurrence (90% vs 71%, P

Background: Cryoballoon ablation for atrial fibrillation (AF) requires adequate contact between the pulmonary vein (PV) antrum and cryoballoon. The surge of intraballoon pressure during the initial phase of ablation may change the balloon's shape and compliance, resulting in balloon dislodgement and loss of PV occlusion. Without continuous monitoring, this phenomenon is often undetected but can be associated with incomplete PV isolation (PVI). Methods: Primary cryoablation of AF was performed in 15 patients. PV occlusion status pre‐ and post‐freezing were analyzed with intracardiac echocardiography (ICE) and dielectric imaging‐based occlusion tool (DIOT) to calculate the incidence of expansion dislodgement of cryoballoon. Results: A total of 105 cryoablation applications were performed on 57 veins, including three common ostiums of left pulmonary veins. In the evaluation of PV occlusion, both modalities reported consistent results in 86.7% of the assessments. Despite complete PV occlusion before ablation, peri‐balloon leak after initiation of freezing was detected by ICE in 5/22 (22.7%) applications and by DIOT in 8/25 (32%) applications. Conclusion: Incidence of expansion dislodgement of the cryoballoon was detected in one‐fourth to one‐third of cryoablation applications depending on the imaging modality used, which was clinically frequent and significant. [ABSTRACT FROM AUTHOR]

Introduction: The circular catheter compatible with current cryoballoon system for atrial fibrillation (AF) ablation is exclusively sensed by impedance‐based electro‐anatomical mapping (EAM) system, limiting the accuracy of maps. We aim to investigate the feasibility and safety of a magnetic‐based circular mapping catheter for AF ablation with cryoballoon. Methods: Nineteen consecutive patients who underwent pulmonary vein isolation (PVI) with cryoballoon for paroxysmal or persistent AF were included. EAMs of left atrium (LA) created by the LASSOSTAR™NAV catheter (Lassostar map) before and after PVI were compared to that generated by a high‐density mapping catheter (Pentaray map) from different aspects including structural similarity, PV angle, LA posterior wall (LAPW) and low voltage areas (LVAs), and the amplitude of far field electrograms (FFEs) recorded by catheters. Results: All patients had successful PVI without major complications. With similar mapping time and density, the LA volume calculated from the Pentaray map and Lassostar map were comparable. There were no significant differences in PV angle of all PVs and PW area (16.8 ± 3.2 vs. 17.1 ± 2.8, p =.516) between Pentaray map and Lassostar map. High structural similarity score was observed between two maps (0.783 in RAO/LAO view and 0.791 in PA view). Lassostar map detected lesser but not statistically significant extension of LVA (13.9% vs. 18.3%, p =.07). Amplitude of FFE was larger at the right superior PV on Lassostar map (0.21 ± 0.16 vs. 0.14 ± 0.11 mV, p =.041) compared to that on the Pentaray map. Conclusion: In our initial experience, PVI with cryoballoon and magnetic‐based circular LASSOSTAR™NAV catheter was safe and effective based on the accurate LA geometry it created. [ABSTRACT FROM AUTHOR]

The care of patients with heart rhythm disorders is often dependent on technologies developed to address their unique clinical needs. Although much innovation occurs in the United States, recent decades have seen a significant proportion of early clinical studies performed outside the United States, driven largely by costly and time‐inefficient processes seemingly inherent to the United States research ecosystem. As a result, the goals of early patient access to novel devices to address unmet needs and efficient technology development in the United States remain incompletely realized. This review will introduce key aspects of this discussion, organized by the Medical Device Innovation Consortium, in an effort to broaden awareness and encourage engagement by stakeholders in an effort to address central issues and therefore further a growing effort to shift Early Feasibility Studies to the United States for the benefit of all involved. [ABSTRACT FROM AUTHOR]