Outcome Of Ventricular Tachycardia Ablation Research Articles

Editorial to “Long‐term outcomes of ventricular tachycardia ablation in repaired tetralogy of Fallot: systematic review and meta‐analysis”

Editorial to “Long‐term outcomes of ventricular tachycardia ablation in repaired tetralogy of Fallot: systematic review and meta‐analysis”

Long-term outcomes of ventricular tachycardia ablation in patients with ischemic and non-ischemic cardiomyopathy: a propensity-score matched analysis

Abstract Background Catheter ablation (CA) has been shown to be effective in the treatment of ventricular tachycardia (VT). Although some observational data suggest that patients with non-ischemic cardiomyopathy (NCIM) have less favorable clinical outcomes when compared to those with an ischemic etiology (ICM), direct comparisons are scarcely reported. We aimed to compare the outcomes of VT ablation in a propensity score-matched population of ICM or NICM patients. Methods Single-center observational registry including 246 consecutive patients with ischemic (ICM, N=166) and non-ischemic cardiomyopathy (NICM, N=80) who underwent drug-resistant VT ablation from 2012 to 2023. A propensity score (PS) was used to match patients in a 1:1 fashion according to the following variables: age, sex, left ventricular ejection fraction (LVEF), NYHA class, electrical storm (ES) at presentation, and previous endocardial VT ablation. The outcomes of interest were VT-free survival and all-cause mortality. Results The PS yielded two groups of 71 patients each (mean age 63±10 years, 92.3% male, mean LVEF 35±10%, 35.9% with ES at presentation, and 23.2% with previous ablation), well matched for baseline characteristics. Those with NICM were more likely to undergo epicardial or combined VT ablation (43.7% vs. 9.9%, P<0.001). The procedural complication rate was low (4.9%, N=7) and similar between groups (P>0.05). During a median follow-up of 27 (IQR 15–45) months, patients with NICM had a significantly lower VT-free survival (53.5% vs. 69.0%, log-rank P=0.037), although there were no differences regarding all-cause mortality (22.5% vs. 16.9%, log-rank P=0.245) – Figure. Multivariate analysis identified NICM (HR 2.34 [95% CI 1.32–4.14], P=0.004), NYHA class III/ IV (HR 2.11 [95% CI 1.11–4.04], P=0.024), and chronic kidney disease (HR 2.23 [95% CI 1.25–3.96], P=0.006), as independent predictors of VT recurrence. Non-inducibility of any VT immediately after ablation was associated with significantly lower rates of VT recurrence (22.8%/ year vs. 42.4%/ year, log-rank P=0.03). Conclusion NCIM patients are at increased risk of VT recurrence after ablation, although long-term mortality was similar to ICM in a propensity-matched cohort. Non-inducibility of any VT after CA is associated with better outcomes.Figure

Substrate characterization and outcomes of ventricular tachycardia ablation in amyloid cardiomyopathy: a worldwide study

Abstract Background the electrophysiological substrate underpinning ventricular tachycardia (VT) in cardiac amyloidosis (CA) remains elusive, and outcomes of catheter ablation in this peculiar population are currently unknown. Purpose we sought to describe the electrophysiological substrate and clinical outcomes of VT ablation in a cohort of patients with CA. Methods we included 19 consecutive patients (mean age, 69±10 years; male sex, 89%) with CA (ATTR, n=13; AL, n=6) undergoing catheter ablation for VT/ventricular fibrillation (VF) between 2013 and 2023 in a retrospective, observational, international study, involving 7 referral European and North American electrophysiology units. The primary efficacy outcome was recurrent VT/VF during follow-up, while the primary safety outcome included major procedure-related adverse events. Results the indication for ablation was drug-refractory VT in 16 patients (84%), and PVC-initiated polymorphic VT/VF in 3 (16%). Catheter ablation was performed using endocardial (n=14, 74%) or endo-epicardial approaches (n=5, 26%). Complete endocardial electroanatomical voltage maps of the left and right ventricles were obtained in 14 (74%) and 6 (32%) patients, respectively. Each patient had evidence of low-voltage areas, most commonly involving the interventricular septum (n=12); late potentials were recorded in 13 patients (68%). A median of 1 (1-2) VTs were inducible per patient; in 10 subjects (43% of mappable VTs), activation mapping was consistent with septal VT origin. Complete procedural success was obtained in 13 patients (68%), at the expense of 4 (21%) major procedure-related adverse events. After a median follow-up of 36 (18-54) months, sustained VT/VF recurrence was observed in 9 patients (47%); survival free from VT/VF recurrence was 74% (95%CI, 56-96%) at 12 months, and 53% (95%CI, 34-94%) at 36-month follow-up; the majority of patients remained on antiarrhythmic drugs (Figure). Low-voltage QRS (HR,21.96; p=0.022) and complete procedural success (HR,0.08; p=0.029) were associated with recurrent VT/VF at multivariable analysis (Figure). Conclusions catheter ablation of VT/VF is associated with favorable acute and mid-term arrhythmia control, yet with substantial risk of procedure-related complications and long-term recurrences. Septal substrate and frailty challenge successful management of patients with CA and VT/VF.Multimodality evaluation of LV substrateMain Study Outcomes

Characterization of ventricular tachycardia ablation in end-stage heart failure patients with left ventricular assist device (CHANNELED-Registry)

Abstract Background Left-ventricular-assist-devices (LVAD) are an established therapy for patients with end-stage heart failure. These patients are at high risk for ventricular tachycardia (VT) and ICD-shocks due to the arrhythmogenic substrate of the underlying cardiomyopathy itself and as the LVAD cannula might be arrhythmogenic, too. Purpose Data on catheter ablation of VT in LVAD patients are scarce and current evidence predominantly consists of case reports and small single-center series. This multicenter registry seeks to systematically assess the mechanism and origin of VA in LVAD patients and to evaluate procedural parameters and outcome of VT ablation in this special subset of patients. Methods Retrospective data of LVAD patients referred for VT ablation at 11 tertiary care centers between January 2017 and August 2023 were included in this multicenter registry. VT mechanisms, procedural data, clinical follow-up, and outcome were assessed. Results We report 49 patients (88% male, age 61±8 years) undergoing 51 ablation procedures included in this ongoing registry. The underlying cardiomyopathy was ischemic in 25/49 patients (51%) and nonischemic in 24/49 patients (49%) with a mean left ventricular ejection fraction of 21%±6% before LVAD implantation. Most catheter ablations were conducted after prior antiarrhythmic drug (AAD) treatment (15/51 on amiodarone, 13/51 on prior intensification of amiodarone treatment, 18/51 on prior combination of two or more AADs). A total of 75 VTs were targeted (39/51 transseptal, 3/51 retrograde aortic, 9/51 combined approaches) and 13/49 patients required VT ablation less than 1 month after LVAD implantation. Of the targeted VTs the majority (69%) were cardiomyopathy related and only 31% of the targeted VTs were related to the LVAD cannula. In 5/51 procedures access site complications and in 1/51 procedures a pericardial effusion occurred; one patient showed a post procedural oxygen desaturation; despite immediate intubation the patient deceased from hypoxic brain injury. No LVAD related complications were observed. A follow-up was available for 35/49 patients. During a median follow-up of 277 days (IQR 78-625 days), 5/35 patients were transplanted and 13/35 died. Patients died after a median time of 124 days (IQR 34-952 days) primarily from heart failure, sepsis, or intracranial bleeding. Of the remaining 17/35 patients, 7/17 patients were arrhythmia-free at a median follow-up of 212 days (IQR 78-639 days). Conclusion Although often chosen as last resort, catheter ablation of VT in LVAD patients is feasible and can be performed safely in this critically ill subset of heart failure patients in experienced centers. Intrinsic myocardial scar seems to be the dominant substrate in these patients but LVAD cannulae contribute to a significant number of VTs. In the presence of severely reduced LV function the VT recurrence remains high despite maximal therapy and prognosis of these patients is limited.

Outcomes of ventricular tachycardia ablation in patients with ischemic and non-ischemic cardiomyopathy: A propensity-score matched analysis

Introduction and objectivesCatheter ablation (CA) is effective in the treatment of ventricular tachycardia (VT). Although some observational data suggest patients with non-ischemic cardiomyopathy (NICM) have less favorable outcomes when compared to those with an ischemic etiology (ICM), direct comparisons are rarely reported. We aimed to compare the outcomes of VT ablation in a propensity-score matched population of ICM or NICM patients. MethodsSingle-center retrospective study of consecutive patients undergoing VT ablation from 2012 to 2023. A propensity score (PS) was used to match ICM and NICM patients in a 1:1 fashion according to age, sex, left ventricular ejection fraction (LVEF), NYHA class, electrical storm (ES) at presentation, and previous endocardial ablation. The outcomes of interest were VT-free survival and all-cause mortality. ResultsThe PS yielded two groups of 71 patients each (mean age 63±10 years, 92% male, mean LVEF 35±10%, 36% with ES at presentation, and 23% with previous ablation), well matched for baseline characteristics. During a median follow-up of 2.3 (interquartile range IQR 1.3–3.8) years, patients with NICM had a significantly lower VT-free survival (53.5% vs. 69.0%, log-rank p=0.037), although there were no differences regarding all-cause mortality (22.5% vs. 16.9%, log-rank p=0.245). Multivariate analysis identified NICM (HR 2.34 [95% CI 1.32–4.14], p=0.004), NYHA class III/IV (HR 2.11 [95% CI 1.11–4.04], p=0.024), and chronic kidney disease (HR 2.23 [95% CI 1.25–3.96], p=0.006), as independent predictors of VT recurrence. ConclusionNon-ischemic cardiomyopathy patients were at increased risk of VT recurrence after ablation, although long-term mortality did not differ.

A comparison of general anesthesia versus monitored anesthesia care during catheter ablation for ventricular tachycardia

Abstract Background Catheter ablation of ventricular tachycardia (VT) may be performed under general anesthesia (GA) or monitored anesthesia care (MAC). There is a paucity of data studying these two sedation strategies with respect to intraprocedural characteristics, and outcomes of VT ablation. Purpose The purpose of this study was to assess the effects of anesthesia techniques on VT inducibility and outcomes. Methods A single-center, retrospective study of patients undergoing catheter ablation for scar-related VT, from 2016-2022, was conducted. Data collected included demographics, comorbidities, medications, relevant laboratory abnormalities, electrocardiograms, echocardiograms, detailed procedural characteristics, and outcomes. Results One hundred sixty-eight patients who underwent a total of 200 VT ablation procedures were included. The patients undergoing GA had a greater burden of comorbidities including congestive heart failure (77.2% vs. 60.9%), hypertension (66.9% vs. 60.0%), atrial arrhythmias (50.7% vs. 43.8%), diabetes mellitus (21.3% vs. 9.4%), chronic kidney disease (44.1% vs. 31.3%), prior stroke (11.8% vs. 10.9%), myocardial infarction (31.6% vs. 29.7%), pre-existing implantable cardioverter-defibrillator (86.8% vs. 71.9%) and had a higher median number of antiarrhythmic drugs at baseline (2 vs. 1) [Figure 1]. There was a greater percentage of patients with non-ischemic cardiomyopathy (58.1% vs. 51.6%) in the GA cohort. The mean left ventricular ejection fraction was not different among the two groups (39.3 ± 13.9 vs. 42.5 ± 15.3). The GA group had more hemodynamic instability at baseline (p < 0.01), and during VT induction (p < 0.01). There was no significant difference in the number of VT induced, or tachycardia cycle length, in each group. Despite higher radiofrequency energy delivery time in the GA group as compared to the MAC group, the GA group had higher VT inducibility post-procedure and were more likely to be discharged on antiarrhythmic drugs. Even though the recurrence of VT was higher in the GA group compared to the MAC group (41.9% vs. 31.3%), the VT-free survival curves were not significantly different by Kaplan-Meier analysis (p=0.19) [Figure 2]. In a multivariate regression analysis, the sedation strategy was not an independent predictor of VT recurrence (p=NS). However, baseline hemodynamic instability was an independent predictor of VT recurrence after accounting for all intraprocedural characteristics (p=0.008). Conclusion Patients undergoing VT ablation under GA have more comorbidities and tend to be on more antiarrhythmic drugs. The GA group had more hemodynamic instability during the procedure and had greater overall VT recurrence, however, not significant in a time-based analysis. The greater overall recurrence in the GA group could be because they represent a sicker population, or the hemodynamics during the procedure preclude adequate ablation of the VT circuit elements.Figure 1Figure 2

Differences in the outcomes of catheter ablation for ventricular tachycardia by sex

Abstract Background Catheter ablation of ventricular tachycardia (VT) has emerged as the mainstay of management for these sick patients. There is a lack of long-term data studying the characteristics and outcomes of VT ablation in females and the comparison with males. Purpose The purpose of the study was to assess the impact of sex on outcomes of catheter ablation for ventricular tachycardia. Methods A single-center retrospective study of 200 procedures in 168 patients undergoing catheter ablation for scar-related VT under GA or MAC sedation was conducted. Data collected included demographics, comorbidities, medications, relevant laboratory abnormalities, electrocardiograms, structural data including echocardiograms and cardiac magnetic resonance imaging, detailed procedural characteristics, and outcomes. Results Females undergoing VT ablation were younger (49.4 ± 15.6 vs. 65.5 ± 12.2 years) [Figure 1]. Females had a lower burden of comorbidities, including congestive heart failure (30.0 % vs. 82.5%), hypertension (27.5% vs. 74.4%), atrial arrhythmias (20.0% vs. 55.6%), chronic kidney disease (25.0% vs. 43.8%), prior myocardial infarction (15.0% & 35.0%), and coronary artery bypass graft surgery (0.0% & 23.8%). Females were on fewer antiarrhythmic drugs at baseline. During the procedure, males had a greater likelihood of undergoing general anesthesia (72.5% vs. 50.0%) and associated hemodynamic instability at baseline (30.0% vs. 12.5%). It was more likely for VT to be induced in males, and females required more induction medications. There was no difference in complication rates between males and females. A greater proportion of males were discharged and maintained on antiarrhythmic drugs after the procedure. There was no significant difference in VT recurrence or long-term mortality. Using Kaplan-Meier analysis, no difference was seen in long-term VT-free survival by sex (p=0.20) [Figure 2]. In a multivariate regression model, female sex had no bearing on the VT-free survival. Conclusion Females undergoing catheter ablation for VT are younger and have fewer comorbidities. They tend to be on fewer antiarrhythmic drugs at baseline, and after ablation. Interestingly, despite a healthier baseline profile, females do not experience less VT recurrence or mortality compared to males. Further study would be needed to investigate this association.Figure 1Figure 2

Abstract 17014: Differences in the Outcomes of Catheter Ablation for Ventricular Tachycardia in Patients With Ischemic versus Non-Ischemic Cardiomyopathy

Background: Catheter ablation is an effective tool to reduce ventricular tachycardia (VT) burden. There is a lack of robust data studying the characteristics and outcomes of VT ablation in patients with ischemic (ICM) versus non-ischemic cardiomyopathy (NICM). Aims: The aim of this study was to assess the impact of ICM vs NICM on outcomes of VT ablation. Methods: A single-center, retrospective study of patients undergoing catheter ablation for VT was conducted. Results: A total of 168 patients, undergoing 200 VT ablation procedures, were included in this study. NICM group (112 procedures) was compared to ICM group (88 procedures). Patients in the ICM group were older (66.6 ± 13.4 vs 58.9 ± 14.4 years) and had higher rates of prior myocardial infarction (65.9% vs 3.6) and coronary artery bypass graft surgery (40.9% vs 1.8%). Overall, ICM group had more comorbidities like hypertension (80.7% vs 52.7%), diabetes mellitus (23.9% vs 12.5%), chronic kidney disease (45.5% vs 35.7%), stroke (17% vs 7.1%), and lower left ventricular ejection fraction (36.8 ± 13.2% vs 43.1 ± 14.7%). The ICM group had lower incidence of prior cardiac valvular surgery (9.1% vs 29.5%). The inducibility of VT (93% vs 93.5%; p= 1.0) and the number of different VT morphologies induced during the case (1.9 ± 1.5 vs 2.3 ± 2.5; p=0.19) was similar between the two groups. There was no acute mortality in either group. There was a non-significant trend towards greater VT recurrence in the NICM group (43.2% vs 33.3%, p= 0.19). However, patients with NICM had a lower VT-free survival as determined by Kaplan-Meier analysis (p=0.05) [Figure]. Long term mortality was higher in ICM group when compared to NICM group (18.2% vs 8.9%, p<0.01). Conclusion: Patients undergoing VT ablation in the NICM group when compared to the ICM group were noted to be younger, had fewer comorbidities, and lower long-term mortality. However, they had significantly less VT-free survival, likely owing to more challenging substrate responsible for VT.

Clinical outcomes and procedural characteristics of ventricular tachycardia ablation in patients with or without electrical storm

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Electrical storm (ES) is a life-threatening clinical condition characterized by the recurrence of three or more episodes of ventricular tachycardia (VT) and/or ventricular fibrillation within 24 hours, leading to ICD therapy. Catheter ablation of VT in patients with ES is a high-risk procedure but has been shown to reduce VT recurrence and the number of appropriate ICD therapies in patients with structural heart disease. Purpose Our study aimed to compare the characteristics and outcomes of VT ablation in patients with or without ES. Methods Our single-center study included a cohort of 39 consecutive patients (31 men, mean age=60.9±18.4 years) who underwent VT ablation between January 2020 and January 2022, 21 of them (53.8%) due to ES and 18 patients (46.2%) had an elective procedure. Clinical and procedural characteristics, VT recurrence, and mortality rates were compared between the two groups. Results Patients with ES were older than patients without ES (67.8 vs 54.2 years, p=0.004), they were mainly presented with ischaemic cardiomyopathy (85.7% vs 27.8%, p<0.0001), had a higher prevalence of congestive heart failure (90.5% vs 44.4%, p=0.001) and a more severe left ventricular dysfunction (LVEF: 30.8% vs 46.9%, p=0.002). During the procedure, in the ES group, all of the patients had left-sided ablation (transaortic: 80.9%, transseptal: 19.1%), while in patients without ES, 72.2% of the procedures were left-sided (p=0.04). In 8/39 patients (20.5%) endo-epicardial access was needed. The number of RF ablation points was significantly higher in the ES group (64.1 vs 36.1 points, p=0.01). Complications were detected only in the ES group: intraprocedural death occurred in one case due to an ES and consequently cardiogenic shock, and one patient had a dissection of the right femoral artery. There was no significant difference regarding procedure time, fluoroscopy time, and radiation exposure. The in-hospital 30-day mortality was 8/21 (28.6%) in patients with ES, while no patients died in the non-ES group. During longer clinical follow-up, there was no significant difference in the recurrence of VT episodes and mortality. Conclusion Patients presented with ES are a more vulnerable population with many comorbidities. Catheter ablation of VT in patients with ES is a more complex procedure with a higher complication rate and these patients have a higher risk of in-hospital mortality. Further studies are needed to determine the optimal timing of VT ablation in this patient population.

MP-453083-11 SAFETY AND OUTCOMES OF VENTRICULAR TACHYCARDIA ABLATION ACROSS AGE GROUPS

A pharmacotherapy approach to the treatment of ventricular tachycardia (VT) is frequently complicated by poor tolerance, persistent ICD shocks and impartial rhythm control. This can be burdensome in an elderly population who frequently have significant comorbidities complicating medical care. Catheter ablation for ventricular tachycardia has been increasingly employed to treat VT, however a paucity of data on the safety and outcomes of VT ablation in octogenarians exists. To examine the safety and outcomes of ventricular tachycardia ablation therapy in octogenarians. The data used was obtained from the National Inpatient Sample (NIS) database from 2016 to 2019. We identified patients ≥ 21 years old with VT as primary diagnoses and underwent ablation during index hospitalization. Patients were divided into 4 age subgroups 20-39, 40-59, 60-79 and ≥ 80 years old. Primary outcome was all-cause mortality and secondary outcomes were transfer to rehab, hospital length-of-stay and in-hospital complications. Univariate and multivariate logistic regression analyses were used to study the association between catheter ablation and primary and secondary outcomes. A total of 23,900 patients undergoing VT ablation were identified. Most patients were between ages of 50-69 years of age (60.3%), followed by 40-59 (25%), ≥ 80 (9.5%), and 20-39 (5.6%). No significant differences in complications including procedure-related pericardial effusion, pericarditis, tamponade, stroke, hemorrhage, or respiratory failure were seen between all age groups. Similarly, no significant differences in hospital length of stay were appreciated across all ages. However, mortality rates were significantly higher in octogenarians (4.2%), compared to those between 60-79 years old (3.2%), 40-59 years (1.5%) and 20-39 years (2.3%) (p-value 0.023). Rehab transfer was also significantly higher in the elderly (p-value <0.001). In this large, real-world database study, we found no significant differences in procedure related complications or hospital length of stay across all age groups undergoing VT ablation. However, in-hospital mortality rates and transfer to rehab were significantly higher in octogenarians compared to younger subgroups. Despite procedural safety, a decision to pursue VT ablation in octogenarians must be carefully weighed against modest increased risks of mortality in this delicate population.

Contemporary approach to catheter ablation of ventricular tachycardia in nonischemic cardiomyopathy.

Nonischemic cardiomyopathy (NICM) comprises a heterogenous group of disorders with myocardial dysfunction unrelated to significant coronary disease. As the use of implantable defibrillators has increased in this patient population, catheter ablation is being utilized more frequently to treat NICM patients with ventricular tachycardia (VT). Progress has been made in identifying multiple subtypes of NICM with variable scar patterns. The distribution of scar is often mid-myocardial and subepicardial, and identifying and ablating this substrate can be challenging. Here, we will review the current understanding of NICM subtypes and the outcomes of VT ablation in this population. We will discuss the use of cardiac imaging, electrocardiography, and electroanatomic mapping to define the VT substrate and the ablation techniques required to successfully prevent VT recurrence.

Relevance of Chronic Total Occlusion for Outcome of Ventricular Tachycardia Ablation in Ischemic Cardiomyopathy.

Background Catheter ablation of ventricular tachycardia (VT) in patients with ischemic cardiomyopathy (ICM) is an effective tool to prevent VT recurrences. Chronic total occlusion (CTO) represents a clinically relevant entity in ICM patients and is an independent predictor of ventricular arrhythmia and mortality. The effects of CTO on the outcome of VT ablation are not well-studied. Objective This analysis aimed to identify the impact of CTO, revascularized, or not revascularized, on the outcome of VT ablation. Methods and Results Of 385 consecutive subjects with ICM-VT who underwent catheter VT ablation for monomorphic VT at Heart Center Leipzig between 2008 and 2017, 108 patients without CTO and 191 patients with CTO were included in the analysis. Within a median follow-up time of 557 days (IQR 149, 1095), VT recurred in 77 (40%) patients in the CTO and 40 (37.0%) in the non-CTO cohort (p = 0.62). In a multivariable model, a 10% stepwise change in LVEF as well as ICD on admission was associated with VT recurrence (HRadj 1.82, 95% CI 1.04–3.18 and HRadj 1.35, 95% CI 1.23–1.61, respectively). Of the CTO cohort before ablation, 45% had received revascularization, which was independently associated with a higher risk for VT recurrence (HR 2.12, 95% CI 1.35–3.34) as compared to nonrevascularized CTO. Conclusion In ICM patients with and without CTO, VT ablation was associated with equal effectiveness with regard to VT recurrence. However, in revascularized CTO patients, the risk of recurrence of VT after ablation was significantly increased.

Substrate Characterization and Outcome of Catheter Ablation of Ventricular Tachycardia in Patients With Nonischemic Cardiomyopathy and Isolated Epicardial Scar.

The substrate for ventricular tachycardia (VT) in left ventricular (LV) nonischemic cardiomyopathy may be epicardial. We assessed the prevalence, location, endocardial electrograms, and VT ablation outcomes in LV nonischemic cardiomyopathy with isolated epicardial substrate. Forty-seven of 531 (9%) patients with LV nonischemic cardiomyopathy and VT demonstrated normal endocardial (>1.5 mV)/abnormal epicardial bipolar low-voltage area (LVA, <1.0 mV and signal abnormality). Abnormal endocardial unipolar LVA (≤8.3 mV) and endocardial bipolar split electrograms and predictors of ablation success were assessed. Epicardial bipolar LVA (27.3 cm2 [interquartile range, 15.8-50.0]) localized to basal (40), mid (8), and apical (3) LV with basal inferolateral LV most common (28/47, 60%). Of 44 endocardial maps available, 40 (91%) had endocardial unipolar LVA (24.5 cm2 [interquartile range, 9.4-68.5]) and 29 (67%) had characteristic normal amplitude endocardial split electrograms opposite the epicardial LVA. At mean of 34 months, the VT-free survival was 55% after one and 72% after multiple procedures. Greater endocardial unipolar LVA than epicardial bipolar LVA (hazard ratio, 10.66 [CI, 2.63-43.12], P=0.001) and number of inducible VTs (hazard ratio, 1.96 [CI, 1.27-3.00], P=0.002) were associated with VT recurrence. In patients with LV nonischemic cardiomyopathy and VT, the substrate may be confined to epicardial and commonly basal inferolateral. LV endocardial unipolar LVA and normal amplitude bipolar split electrograms identify epicardial LVA. Ablation targeting epicardial VT and substrate achieves good long-term VT-free survival. Greater endocardial unipolar than epicardial bipolar LVA and more inducible VTs predict VT recurrence.

Long-term outcome of ventricular tachycardia ablation in patients who did not undergo programmed electrical stimulation after ablation.

Ventricular arrhythmia inducibility is one of the ideal endpoints of ventricular tachycardia (VT) ablation. However, it may be challenging to implement programmed electrical stimulation (PES) at the end of the procedure under several circumstances. The long-term outcome of patients who did not undergo PES after VT ablation remains largely unknown. To investigate the details and long-term outcome of VT ablation in patients who did not undergo PES at the end of the ablation procedure. Among 183 VT ablation procedures in patients with structural heart disease who underwent VT ablation using an irrigated catheter, we enrolled those who did not undergo PES after VT ablation. VT ablation strategy involved targeting clinical VT plus pacemap-guided substrate ablation if inducible. When VT was not inducible, substrate-based ablation was performed. The primary endpoint was VT recurrence. In 58 procedures, post-ablation VT inducibility was not assessed. The causes were non-inducibility of sustained VT before ablation (27/58, 46.6%), long procedure time (27.6%, mean 392min), complications (10.3%), intolerant hemodynamic state (10.3%), and inaccessible or unsafe target (6.9%). With regard to the primary endpoint, 23 recurrences (39.7%) were observed during a mean follow-up period of 2.5years. Patients with non-inducibility before ablation showed less VT recurrences (4/27, 14.8%) during follow-up than patients with other causes of untested PES after ablation (19/31, 61.2%) (Log-rank < 0.001). VT recurrence was not observed in approximately 60% of the patients who did not undergo PES at the end of the ablation procedure. PES after VT ablation may be not needed among patients with pre-ablation non-inducibility.

Substrate Characterization and Outcomes of Ventricular Tachycardia Ablation in TTN (Titin) Cardiomyopathy: A Multicenter Study.

[Figure: see text].

Abstract 17371: In-Hospital Outcomes of Ablation for Ventricular Tachycardia in Heart Failure With Reduced Ejection Fraction

Introduction: Ventricular tachycardia (VT) is a significant cause of morbidity and mortality in patients with heart failure with reduced ejection fraction (HFrEF). Hypothesis: Data on efficacy, safety, and outcomes of catheter ablation for VT in HFrEF have not been studied well. Methods: The 2002-2014 Nationwide Inpatient Sample (NIS) was used to identify all hospitalizations with a principle diagnosis of VT (International Classification of Diseases, Ninth Edition, Clinical Modification [ICD-9-CM] code 427.1) and a secondary diagnosis of HFrEF. Patients who underwent catheter ablation were identified using ICD-9-CM procedure code 37.34. Results: Of 228,557 patients with HFrEF &amp; VT, 5845 (2.56%) underwent catheter ablation. The prevalence of Diabetes Mellitus (DM) and Chronic Kidney disease (CKD) was higher in the reference population contrary to a higher prevalence of prior myocardial infarction (MI), coronary bypass and AICD in those undergoing CA. The frequency of complications in the ablation group was 19.47%, the most common being post-operative hemorrhage (8.3%). This was followed by myocardial infarction (5.34%), pericardial complications (3.38%), and neurological complications (2.14%) (Figure 1.). The odds of in-hospital mortality were lower in the CA group compared to the reference group (5.08% vs 9.42%, p&lt;0.05). Conclusions: Compared to medical therapy, VT ablation in HFrEF is associated with lower mortality though with significant complication rate. This suggests a need for future studies identifying the safety measures in VT ablations and instituting appropriate interventions to improve overall VT ablation outcomes.

Pre-procedural image-guided versus non-image-guided ventricular tachycardia ablation-areview.

BackgroundMagnetic resonance imaging and computed tomography in patients with ventricular tachycardia (VT) after myocardial infarction (MI) helps to delineate scar from healthy tissue. Image-guided VT ablation has not yet been studied on a large scale.ObjectiveThe aim of the meta-analysis was to compare the long-term outcome of image-guided VT ablation with a conventional approach for VT after MI.MethodsEight electronic bibliographic databases were searched to identify all relevant studies from 2012 until 2018. The search for scientific literature was performed for studies that described the outcome of VT ablation in patients with an ischaemic substrate. The outcome of image-guided ablation was compared with the outcome of conventional ablations.ResultsOf the 2990 citations reviewed for eligibility, 38 articles—enrolling a total of 7748 patients—were included into the meta-analysis. Five articles included patients with image-guided ablation. VT-free survival was 82% [74–90] in the image-guided VT ablation versus 59% [54–64] in the conventional ablation group (p < 0.001) during a mean follow-up of 35 months. Overall survival was 94% [90–98] in the image-guided versus 82% [76–88] in the conventional VT ablation group (p < 0.001).ConclusionsImage-guided VT ablation in ischaemic VT was associated with a significant benefit in VT-free and overall survival as compared with conventional VT ablation. Visualising myocardial scar facilitates substrate-guided ablation procedures, pre-procedurally and by integrating imaging during the procedure, and may consequently improve long-term outcome.Electronic supplementary materialThe online version of this article (10.1007/s12471-020-01485-z) contains supplementary material, which is available to authorized users.

Abstract 17073: Intraprocedural Use of Dopamine During Ventricular Tachycardia (VT) Ablation is Associated With Greater Number of VTs Induced and Increased Need for Cardioversions

Introduction: Hemodynamic drugs are frequently used in patients with heart failure, despite arrhythmogenic effects. In certain situations, dopamine has been associated with increased arrhythmias and mortality. There are no known studies reviewing the impact of hemodynamic drugs used during VT ablations on procedural outcomes. Hypothesis: We sought to determine whether intra-procedural use of dopamine, dobutamine, or phenylephrine affected the number of induced VTs, required cardioversions, or the acute success of VT ablations. Methods: We conducted a retrospective review for all VT ablations from 2013-17 at our institution. Patient and procedural details were collected for 149 VT ablations. Results: The cohort was 81% male, and 67% had cardiomyopathy of which 53% were ischemic with a mean EF of 29.1% (CI 26.7- 31.4). Vasoactive drugs were used in 87% of patients undergoing VT ablation: phenylephrine (67%), dopamine (40%), dobutamine (37%). After adjusting for heart failure and procedural time, use of dopamine, but not phenylephrine or dobutamine, was associated with a greater number of induced VTs (p =0.02, Fig. 1a). Adjusting for the same factors, dopamine and dobutamine were significantly associated with increased need for cardioversions (p &lt; 0.01). Dobutamine, but not dopamine or phenylephrine, was associated with lower acute procedural success (OR 0.25, CI 0.08-0.77, P = 0.01). Conclusions: Different vasoactive drugs may have differential effects on VT ablation outcomes. The focus of VT ablation is usually on VT mechanism and substrate, but attention to other factors, such as vasoactive drugs, may be warranted to determine their effect on procedural outcomes.

Prognostic Value of Noninducibility on Outcomes of Ventricular TachycardiaAblation: A VANISH Substudy.

This study sought to evaluate the predictive value of noninducibility on long-term outcomes. The traditional endpoint for catheter ablation of ventricular tachycardia (VT) is noninducibility of VT by programmed stimulation; however, the definition of inducibility remains variable and its prognostic value limited by nonstandardized periprocedural antiarrhythmic drug therapy and implantable cardioverter-defibrillator programming in prior observational studies. The VANISH trial randomized patients with prior myocardial infarction and VT to ablation (with an endpoint of noninducibility of VT≥300 ms after ablation) versus antiarrhythmic drug escalation. Patients enrolled in the VANISH study randomized to catheter ablation were included. The relationship between post-ablation inducibility and the primary composite endpoint (death, VT storm >30 days, or appropriate implantable cardioverter-defibrillator shock >30 days) was assessed using a time-to-event analysis, adjusting for other clinical and procedural characteristics. A total of 129 patients from the ablation arm were included in the primary analysis, of which 51 were noninducible post-ablation compared with 78 who had inducible VT or in whom inducibility testing was not performed. There were no significant baseline characteristic or procedural differences except for increased implantable cardioverter-defibrillator shocks before randomization in the noninducible group. In multivariate analysis, inducibility significantly increased the risk of death, appropriate shock, or VT storm after 30 days (HR: 1.87; p= 0.017). Inducibility of any VT post-ablation was associated with an increased risk of the composite endpoint in the VANISH trial. A randomized trial is required to confirm whether more aggressive ablation targeting faster induced VTs (<300 ms) can improve outcomes.

Defining the Outcome of Ventricular Tachycardia Ablation: Timing and Value of Programmed Ventricular Stimulation.

Catheter ablation of ventricular tachycardia (VT) is effective to prevent arrhythmia episode-related implantable cardioverter defibrillator shocks. However, recurrences in noninducible patients at programmed ventricular stimulation (PVS) are substantial. From May 2013 to September 2015, 218 PVSs were performed 6 days (5-7) after ablation (186 noninvasive programmed stimulations and 32 invasive PVS) in 210 consecutive patients (ischemic, 48%; median left ventricular ejection fraction, 37%; syncope, 35% with trauma associated 6%), while patients were awake and under β-blocker therapy. After ablation, implantable cardioverter defibrillators were programmed according to noninvasive programmed stimulations results (class A-noninducible; class B-nondocumented inducible VT; and class C-documented inducible VT), with high and delayed VT detection intervals. Concordance between PVS end procedure and PVS day 6 was 67%. Positive predictive value and negative predictive value were higher for PVS day 6 (53% and 88% versus 43% and 71%). Ischemic and patients with preserved ejection fraction showed the highest negative predictive value (91% and 96%). Among 46 of 174 (26%) noninducible patients at PVS end procedure, but inducible at day 6, 59% had VT recurrence at 1-year follow-up; recurrences were 9% when both studies were noninducible. There were no inappropriate shocks; incidence of syncope was 3%; and none was harmful. The rate of appropriate shocks per patient per month according to noninvasive programmed stimulations results was significantly reduced, comparing the month before and after ablation (class A: 2 [0.75-4] versus 0; class B: 2 [1-4] versus 0; class C: 2 [1-4] versus 0; P<0.001). PVS at day 6 predicts VT recurrence more accurately allowing to identify patients who might benefit from a redo ablation and addressing implantable cardioverter defibrillator programming.