Tachycardia Ablation In Patients Research Articles

First in Asia: Ventricular tachycardia ablation in patients with mechanical aortic and mitral valves using right atrium to left ventricle approach

First in Asia: Ventricular tachycardia ablation in patients with mechanical aortic and mitral valves using right atrium to left ventricle approach

Abstract 4113336: Characteristics and Outcomes of Ventricular Tachycardia Ablation in Patients with the HeartMate 3 Left Ventricular Assist Devices: Results From a Large Single-Center Registry

HeartMate 3 (HM3) is a fully magnetically levitated continuous flow left ventricular assist device (LVAD). In patients with HM3 and recurrent ventricular tachycardia (VT), data on the outcomes of catheter ablation (CA) are insufficient. We report our institutional experience with CA of VT in patients with the HM3.Consecutive patients with HM3 and recurrent drug-refractory VT undergoing CA were included. Ablation sites were identified using activation/entrainment mapping (stable VTs) and/or late/fractionated potential ablation and pace-mapping (unstable VTs). Between 2016-2023 a total of 431 patients (age 58±13, INTERMACS 3±0.98, 44% ischemic cardiomyopathy) received an HM3 LVAD at our institution. Of these, 15 (3.4%) underwent CA for recurrent VT despite therapy with 1.3±0.8 antiarrhythmic drugs a median of 700 days from the LVAD surgery (2 patients <1 month from the surgery). The LV access was transseptal in 12 (80%) cases, retrograde aortic in 2 (13%) and both in 1 (7%). A total of 23 distinct VTs were targeted. Of these, 21 (91%) were mapped with activation/entrainment mapping, always utilizing an intracardiac RV reference due to excessive surface ECG noise, and 2 (9%) were hemodynamically unstable with reduced LVAD flows and targeted with substrate-based ablation. A total of 3 (13%) VTs were targeted adjacent to the HM3 inflow cannula, and 20 (87%) from substrate remote from the HM3 cannula. At post-procedural programmed ventricular stimulation, non-inducibility of all targeted VTs was achieved in 13 (87%) patients, 1 patient had residual inducible clinical VT, and in 1 patient no post-procedural programmed stimulation was performed. Periprocedural complications occurred in 1 (7%) case (small pericardial effusion not requiring intervention). At 12 months follow-up following the index procedure, no death occurred and one patient received heart transplantation. Of the remaining 14 patients, 6 (42%) remained free from VT (2 with VT ablation <1 month post-LVAD and 12 with VT ablation >=1 month post-LVAD). In this large single-center HM3 registry, a minority of patients underwent CA for recurrent drug-refractory VT (3.4% over a 7-year period). CA of VT in HM3 recipients is feasible and appears safe also when performed soon after LVAD surgery. Myocardial scar from the underlying cardiomyopathic process rather than the apical cannula is the dominant substrate responsible for VT in these patients.

Impella-assisted ventricular tachycardia ablation in patient with dilated cardiomyopathy and electrical storm.

Impella-assisted ventricular tachycardia ablation in patient with dilated cardiomyopathy and electrical storm.

Value of multimodality imaging for ventricular tachycardia ablation in patients with structural heart disease

Value of multimodality imaging for ventricular tachycardia ablation in patients with structural heart disease

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

High-density mapping-guided ventricular tachycardia ablation in patients with ischemic cardiomyopathy: outcomes from a tertiary center cohort in Switzerland

Abstract Background Substrate-based ablation has emerged as a successful technique for VT ablation, especially in patients with ischemic cardiomyopathy with markedly reduced left ventricular function. High-density mapping catheters provide high-resolution electroanatomical maps and better discrimination of abnormal substrates and local activation in the heart chambers, making them a valuable and safe resource in the electrophysiology laboratory. Purpose The purpose of this study was to investigate differences in procedural characteristics and clinical outcomes of VT ablation with ischemic cardiomyopathy. VT ablations were guided by two mapping strategies: high-density mapping using a high-density mapping catheter and conventional mapping using an ablation catheter. Methods Patients with ischemic cardiomyopathy receiving VT ablation at our center between January 2018 and June 2023 were retrospectively included. Procedural characteristics and clinical outcomes were compared between patients receiving high-density mapping with a multielectrode-mapping catheter vs conventional mapping with a single-tip irrigated ablation catheter. Results Eighty-four patients with ischemic cardiomyopathy who underwent VT ablation were consecutively included (mean age 67 ± 12 years, mean LVEF 32 ± 11 %, 79 (94%) males). Fifty-seven (68 %) procedures were performed using high-density mapping, and 27 (32 %) conventional mapping. In the high-density mapping and conventional mapping group, the total procedure time was 256 ± 77 min vs. 232 ± 61 min (P < 0.05) and the total fluoroscopic dose was 1643 ± 204 μGy.m2 vs. 948 ± 105 μGy.m2 (P < 0.05), respectively,. However, there was no difference between the two groups in terms of acute success (84% vs 80%, P > 0.05) or major complications (5% vs 4%, P > 0.05). The mean duration of follow-up was 2.6 years (4 - 51 months). The 1-year mortality rates were 4% vs 7% in the high-density mapping and conventional mapping groups, respectively (P < 0.05). The 3-month and 1-year single-procedural sustained VT/VF-free rates were 77% vs 59% and 74% vs 63%, respectively (P < 0.05). The 1-year incidence of sustained VT/VF recurrence was 7.0 per 100 person-years in high-density mapping group, compared with 7.4 per 100 person-years in the conventional group. Conclusions VT ablation in patients with ischemic cardiomyopathy using high-density mapping appears to be superior to conventional mapping in terms of reducing postprocedural VT/VF recurrence and a subsequent reduction of overall mortality.Figure 1Figure 2

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.

Catheter Ablation of Ventricular Tachycardia in Ischemic Heart Disease: What Is Known and New Perspectives.

This review aims to evaluate current evidence regarding ventricular tachycardia ablation in patients with ischemic heart disease and explore novel approaches currently developing to improve procedural and long-term outcomes. Recently published trials (PARTITA, PAUSE-SCD, and SURVIVE-VT) have demonstrated the prognostic benefit of prophylactic ventricular tachycardia ablation compared to current clinical practice. Advanced cardiac imaging provides a valuable pre-procedural evaluation of the arrhythmogenic substrate, identifying ablation targets non-invasively. Advanced cardiac mapping techniques allow to better characterize arrhythmogenic substrate during ablation procedure. Emerging technologies like pulsed field ablation and ultra-low temperature cryoablation show promise in ventricular tachycardia ablation. Advancements in mapping techniques, ablation technologies, and pre-procedural cardiac imaging offer promise for improving ventricular tachycardia ablation outcomes in ischemic heart disease.

Machine-Learning-Based Prediction of 1-Year Arrhythmia Recurrence after Ventricular Tachycardia Ablation in Patients with Structural Heart Disease.

Ventricular tachycardia (VT) recurrence after catheter ablation remains a concern, emphasizing the need for precise risk assessment. We aimed to use machine learning (ML) to predict 1-month and 1-year VT recurrence following VT ablation. For 337 patients undergoing VT ablation, we collected 31 parameters including medical history, echocardiography, and procedural data. 17 relevant features were included in the ML-based feature selection, which yielded six and five optimal features for 1-month and 1-year recurrence, respectively. We trained several supervised machine learning models using 10-fold cross-validation for each endpoint. We observed 1-month VT recurrence was observed in 60 (18%) cases and accurately predicted using our model with an area under the receiver operating curve (AUC) of 0.73. Input features used were hemodynamic instability, incessant VT, ICD shock, left ventricular ejection fraction, TAPSE, and non-inducibility of the clinical VT at the end of the procedure. A separate model was trained for 1-year VT recurrence (observed in 117 (35%) cases) with a mean AUC of 0.71. Selected features were hemodynamic instability, the number of inducible VT morphologies, left ventricular systolic diameter, mitral regurgitation, and ICD shock. For both endpoints, a random forest model displayed the highest performance. Our ML models effectively predict VT recurrence post-ablation, aiding in identifying high-risk patients and tailoring follow-up strategies.

Use of CT Integration During Ventricular Tachycardia Ablation in Patients With Tetralogy of Fallot

Use of CT Integration During Ventricular Tachycardia Ablation in Patients With Tetralogy of Fallot

Abstract 16093: Hemodynamic Implications of Transseptal Access for Ventricular Tachycardia Ablation in Patients With Left Ventricular Assist Devices

Introduction: Ventricular tachycardia (VT) is common in patients with left ventricular assist devices (LVAD), and catheter ablation can be an effective treatment strategy. Although transseptal approach for LV mapping and ablation is often preferred, iatrogenic atrial septal defect (ASD) after transseptal access may theoretically result in clinically significant right-to-left shunting. The short- and long-term implications of transseptal puncture, including hemodynamic changes in LVAD patients, remain uncertain. Methods and Results: From 2013-2023, 15 LVAD patients (age 68.5±12 years; 2 women) underwent 18 VT ablation procedures with single transseptal access for LV ablation without ASD closure afterwards. Clinical VT was eliminated in 83%. No patients had prior PFO/ASD; Mean RVSP was 45mmHg, 6 (40%) had pulmonary hypertension, and 8 (53.3%) had moderate or severe RV dysfunction. All patients had previously failed at least 1 antiarrhythmic drug (amiodarone 100%; sotalol 33%; mexiletine 94%). Procedural complications occurred in 3 procedures (all related to vascular access, none directly related to transseptal access; 1 patient with interrupted IVC requiring transhepatic access had bleeding due to transection of intercostal artery requiring arterial embolization). Post-procedure echocardiograms (n=14; mean time to echo 90±116 days) showed no intra-cardiac shunting or persistent ASD. Right heart catheterization (pre: n=12; post: n=8, at mean follow-up 187±243 days) showed similar pre- and post-ablation RA pressures (11.6 vs 14.9 mmHg, p =0.24) and wedge pressures (14.9 vs 20.4 mmHg, p =0.8) with absence of significant shunting based on pre- and post-ablation arterial (95.2% vs 97.7%, p =0.06) and PA oxygen saturations (56.5% vs 51.3%, p =0.29). No episodes of clinically significant hypoxia occurred after ablation. Conclusion: Transseptal access for VT ablation can be safely performed in LVAD patients and is unlikely to result in clinically or hemodynamically significant residual shunting over long-term follow-up. Therefore, empiric ASD closure after transseptal access in all LVAD patients is likely unnecessary.

Outcomes After Supraventricular Tachycardia Ablation in Patients With Group 1 Pulmonary Hypertension.

Pulmonary hypertension (PH) is associated with right ventricular pressure overload and atrial remodeling, which may result in supraventricular tachycardias (SVTs). The outcomes of catheter SVT ablation in patients with World Health Organization (WHO) group 1 PH are incompletely characterized. We conducted a retrospective cohort study of all patients with WHO group 1 PH undergoing catheter SVT ablation during a 10-year period at a major academic tertiary care hospital. Baseline patient characteristics and procedural outcomes at 3 months and 1 year were extracted from the electronic medical record. Ablation of 60 SVTs was attempted in 38 patients with group 1 PH. The initial procedural success rates were 80% for atrial fibrillation (AF, n = 5), 89.7% for typical atrial flutter (AFL, n = 29), 57.1% for atypical AFL (n = 7), 60% for atrial tachycardia (AT, n = 15), and 75% for atrioventricular nodal reentrant tachycardia (AVNRT, n = 4). The 1-year post-procedural recurrence rates were 100% for AF (n = 4), 25% for typical AFL (n = 20), 50% for atypical AFL (n = 2), and 28.6% for AT (n = 7). No patients had recurrent AVNRT (n = 2). There were seven (18.4%) peri-procedural decompensations requiring pressor initiation and transfer to intensive care and one (2.6%) peri-procedural death. The study demonstrates that SVT ablation in group 1 PH can be performed relatively safely and effectively, albeit with lower initial success rates and higher risk of clinical decompensation than in the general population. Recurrence rates at 1 year were higher in AF and atypical AFL ablations and similar for typical AFL and AT ablations when compared to the general population.

Long-term success of a multi-electrode substrate mapping and ablation strategy versus a classic single tip mapping and ablation strategy for ventricular tachycardia ablation in patients with ischemic cardiomyopathy.

Over the past years, mapping and ablation techniques for the treatment of ventricular tachycardia (VT) have evolved rapidly. High Density (HD) substrate mapping is now routine and pre-procedural imaging is increasingly used. The additional value of these techniques for long-term VT-free survival is not clear. We compared baseline and procedural characteristics, procedural success, safety and outcome of mapping and ablation of ventricular tachycardia in patients with ischemic heart disease between two groups. (1) Low Density (LD) group: VT mapping and ablation with a 4mm single tip catheter (2) HD group: HD substrate mapping with the Pentaray (Biosense Webster, USA) or HD Grid (Abbott, USA) catheter and ablation with a 4mm single tip catheter. VT ablation was performed in 133 patients (71 patients in LD group and 62 patients in HD group). The median follow-up was 5.0 years in LD group and 2.0 years in HD group. One-, two-, and five-year VT recurrence rates were 47%, 56%, and 65% in the LD group versus 39%, 50%, and 55% in the HD group (log-rank test for VT recurrence p=.70). One-, two-, and five-year ICD shock recurrence rates were 14%, 18%, and 24% in the LD group versus 8%, 15%, and 19% in the HD group (log-rank test for ICD-shock p=.79). All-cause mortality, cardiac (non-arrhythmic), and arrhythmic death, were similar in both groups. Severe procedural complications (tamponade, stroke, or procedural death) occurred in four patients (5%, 1 vascular, 3 tamponade) in the LD group versus two patients (3%, both tamponade) in the HD group (NS). In univariate and multivariable analysis, only a higher LVEF was significantly associated with VT-free survival. HD mapping was not significantly associated with VT-free survival. Anterior infarct location and age were significantly associated with ICD recurrent shock in both univariate and multivariable analyses. In patients with ischemic cardiomyopathy, a HD substrate mapping, and ablation strategy did not lead to higher VT-free survival and shock-free survival compared to a single tip mapping and ablation strategy. In this study, only LVF is an independent predictor for VT recurrence. Anterior infarct location and age predict recurrent ICD shocks.

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.

Machine learning based prediction of 1-year arrhythmia recurrence after ventricular tachycardia ablation in patients with structural heart disease

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Project no. NVKP_16-1–2016-0017 (’National Heart Program’) - National Research, Development and Innovation Fund of Hungary Thematic Excellence Programme (2020-4.1.1.-TKP2020) of the Ministry for Innovation and Technology in Hungary Background Ventricular tachycardia (VT) is a life-threatening condition. Catheter ablation treatment is often successful, however post procedural VT recurrence still remains an issue. Therefore, there is a demand for an accurate risk stratification system to assess the probability of arrhythmia recurrence after the procedure. Objective We aimed to implement a machine learning (ML) pipeline to predict 1-year VT recurrence in patients with structural heart disease (SHD) undergoing VT ablation. Methods For 297 patients who underwent VT ablation, we collected medical history, laboratory, echocardiography, and procedural data. Following manual and ML-based feature selection, we trained several supervised machine learning models to predict 1-month and 1-year recurrence. The area under the receiver operating characteristic curve (AUC) was calculated to quantify the models’ performance. Results 1-year VT recurrence was observed in 107 (36%) cases. The best predictions of VT recurrence were demonstrated by random forest models utilizing 7 input features [1-month AUC: 0.74; 1-year AUC: 0.76]. These models significantly outperformed a previously published risk score, the I-VT score [AUC: 0.63, p=0.024] on our data. The most important predictors of recurrence were the number of VT morphologies during the procedure, electrical storm, left ventricular ejection fraction, left ventricular end systolic diameter, and the severity of mitral regurgitation. Conclusion Our machine learning model can efficiently predict VT recurrence in SHD patients undergoing VT ablation. Thus, it could facilitate the prompt identification of high-risk patients and the personalization of treatment and follow-up strategies, ultimately leading to improved outcomes.

Acute and long-term success of ventricular tachycardia ablation in patients with ischemic heart disease in a Mexican center

Objective. To report the results of ventricular tachycardia (VT) catheter ablation in ischemic heart disease (IHD), and to identify risk factors associated with recurrence in a Mexican center. Materials and methods. We made a retrospective review of the cases of VT ablation performed in our center from 2015 to 2022. We analyzed the characteristics of the patients and those of the procedures separately and we determined factors associated with recurrence. Results. Fifty procedures were performed in 38 patients (84% male; mean age 58.1 years). Acute success rate was 82%, with a 28% of recurrences. Female sex (OR 3.33, IC 95% 1.66–6.68, p=0.006), atrial fibrillation (OR 3.5, IC 95% 2.08–5.9, p=0.012), electrical storm (OR 2.4, IC 95% 1.06–5.41, p=0.045), functional class greater than II (OR 2.86, IC 95% 1.34–6.10, p=0.018) were risk factors for recurrence and the presence of clinical VT at the time of ablation (OR0.29, IC95% 0.12–0.70, p=0.004) and the use of more than 2 techniques for mapping (OR 0.64, IC 95% 0.48–0.86, p=0.013) were protective factors. Conclusions. Ablation of ventricular tachycardia in ischemic heart disease has had good results in our center. The recurrence is similar to that reported by other authors and there are some factors associated with it.

Causes of Early Mortality After Ventricular Tachycardia Ablation in Patients With Reduced Ejection Fraction

BackgroundRecognition of the causes of early mortality after ventricular tachycardia (VT) ablation in patients with reduced left ventricular ejection fraction (LVEF) is an essential step toward improving postprocedural outcomes. ObjectivesThis study sought to determine the causes of early mortality (≤30 days) after VT ablation in patients with reduced LVEF and to understand further the circumstances surrounding death after the procedure. MethodsWe performed a retrospective analysis of all patients undergoing VT ablation in patients with reduced LVEF from January 1, 2013, to November 10, 2021, at the Mayo Clinic (Rochester, Phoenix, and Jacksonville). Causes of death were identified through a detailed chart review of the electronic health record within the Mayo Clinic system and outside records. ResultsA total of 503 patients (mean age 63 ± 13 years, 11.2% women) with ejection fraction <50% were included in the study. The 30-day all-cause mortality rate was 5.0% (n = 25), and the mortality rate due to a procedural complication was 0.4%. Among all 30-day deaths, recurrent VT was the most common primary cause of death (44.0%). This was followed by decompensated heart failure (28.0%), procedure-related death (8.0%), cerebrovascular accident (4.0%), and infection (4.0%). Most patients (91.0%) who died from VT had VT recurrence within 3 days of the ablation. The average PAINESD score among early mortality was 20 ± 4, and 92.0% of these patients (n = 23) had a score >15. Significant predictors of early mortality included nonischemic cardiomyopathy, lower LVEF, electrical storm, and ventricular fibrillation. ConclusionsThe overall early mortality (≤30 days) rate after catheter ablation of VT in patients with reduced LVEF was 5.0%, but the death rate directly due to a procedural complication was only 0.4%. The most common cause of death was recurrent VT, followed by heart failure. Further research into ablation strategies is vital to improving the safety, efficacy, and durability of VT ablation.

Magnetic resonance imaging and histopathology of catheter ablation lesions after ventricular tachycardia ablation in patients with nonischemic cardiomyopathy.

Late gadolinium enhanced cardiac magnetic resonance (LGE-CMR) imaging may help identify radiofrequency ablation lesions, which have been poorly described in patients with nonischemic cardiomyopathy (NICM). The purpose of this study was to describe LGE-CMR characteristics of ablation lesions in patients with NICM and correlate them with histopathology. Twenty-six patients (24 men; ejection fraction 38% ± 14%; age 61 ± 9 years) who had undergone CMR imaging after ventricular tachycardia (VT) ablation were included. Areas of both dark and bright core lesions correlating with previous radiofrequency ablation lesions were identified. Histology was performed on an explanted heart. Mean time between the ablation procedure and the LGE-CMR study was 8 [2-20] months. Twenty-three of 26 patients demonstrated dark core lesions (volume 2.16 ± 1.8 cm3; thickness 3.6 ± 1.3 mm) with transmurality of 42% ± 16% overlaying areas of intramural or transmural LGE. Fourteen of 26 patients demonstrated bright core lesions (volume 0.8 ± 0.6 cm3; depth 4.15 ± 1.76 mm) with transmurality of 34% ± 14%, which was located in areas without underlying LGE in 11 of 13 patients. Both dark and bright core lesions were visualized on standard clinical LGE-CMR imaging obtained in the acute setting and chronic settings (within 3 days and up to 2090 days postablation). Histopathologic analysis demonstrated coagulation necrosis in the area that corresponded to dark core lesions in the postablation CMR. Ablation lesions can be detected by LGE-CMR after VT ablation in NICM patients and have a different appearance than scar tissue. These lesions can be observed in the acute and chronic settings after ablations.

Integration of 3D nuclear imaging in 3D mapping system for ventricular tachycardia ablation in patients with implanted devices: Perfusion/voltage retrospective assessment of scar location.

The identification of low-voltage proarrhythmic areas for catheter ablation of scar-mediated ventricular tachycardia (VT) remains challenging. Integration of myocardial perfusion imaging (single-photon emission computed tomography/computed tomography; SPECT/CT) and electroanatomical mapping (EAM) may improve delineation of the arrhythmogenic substrate. To assess the feasibility of SPECT/CT image integration with voltage maps using the EnSite Precision system (Abbott) in patients undergoing scar-mediated VT ablation. Patients underwent SPECT/CT imaging prior to left ventricular (LV) EAM with the EnSite Precision mapping system. The SPECT/CT, EAM data, and ablation lesions were retrospectively co-registered in the EnSite Precision system and exported for analysis. Segmental tissue viability scores were calculated based on SPECT/CT perfusion and electrogram bipolar voltage amplitude. Concordance, specificity, and sensitivity between the 2 modalities as well as the impact of SPECT/CT spatial resolution were evaluated. Twenty subjects (95% male, 67 ± 7 years old, left ventricular ejection fraction 36% ± 11%) underwent EAM and SPECT/CT integration. A concordance of 70% was found between EAM and SPECT/CT for identification of cardiac segments as scar vs viable, with EAM showing a 68.5% sensitivity and 76.4% specificity when using SPECT/CT as a gold standard. Projection on low-resolution 3D geometries led to an average decrease of 38% ± 22% of the voltage points used. The study demonstrated the feasibility of integrating SPECT/CT with EAM performed retrospectively for characterization of anatomical substrates during VT ablation procedures.

Impact of early ventricular tachycardia ablation in patients with an implantable cardioverter-defibrillator: An updated systematic review and meta-analysis of randomized controlled trials

There is limited information on whether early catheter ablation (CA) for ventricular tachycardia (VT) is associated with better outcomes compared with alternative strategies in patients with implantable cardioverter-defibrillator (ICD). The purpose of this article was to assess the efficacy of early VT CA in patients with ICD. EMBASE, PubMed, and Cochrane were searched from inception to April 2022. Randomized controlled trials comparing the efficacy of early VT CA with control groups, both in patients with ICD, were included in the analysis. Data on effect estimates in individual studies were extracted and combined via random effects meta-analysis using the DerSimonian and Laird method, a generic inverse variance strategy. Nine randomized controlled trials with 1106 patients (n = 1018, 92.1% with ischemic cardiomyopathy and n = 88, 7.9% with nonischemic cardiomyopathy) were evaluated. VT CA was associated with reduced VT recurrences (odds ratio [OR] 0.64; P = .007), appropriate ICD shocks (OR 0.53; P = .002), ICD therapies (OR 0.54; P=.002), and cardiovascular hospitalization (OR 0.67; P=.004). However, no significant differences were observed in terms of mortality rate, heart failure hospitalization, and quality of life between the early VT CA and control groups. Early CA was beneficial in reducing VT burden and ICD therapies. However, it did not affect mortality rate and quality of life. Since most patients in the included studies presented with ischemic cardiomyopathy, further studies on nonischemic cardiomyopathy should be conducted to validate if early CA has similar outcomes.