Clinical Outcomes in Patients With Dilated Cardiomyopathy and Ventricular Tachycardia

Extrastimuli-assisted functional mapping improves ventricular tachycardia ablation outcomes: A systematic review, meta-analysis, and meta-regression

BACKGROUND

In the context of ventricular tachycardia (VT) ablation, functional electroanatomic mapping techniques may help identify arrhythmogenic substrates in scarred and normal voltage areas. In addition, extrastimuli-assisted (dynamic) mapping may be more effective than intrinsic rhythm (static) approaches to uncover key ablation targets, potentially improving procedure outcomes.

OBJECTIVE

We aimed to assess the efficacy and safety of functional mapping-assisted VT ablation and to compare procedural outcomes between dynamic and static mapping approaches.

METHODS

PubMed/MEDLINE, Scopus, Web of Science, and Cochrane databases were searched using MeSH terms ventricular tachycardia ablation, functional mapping, recurrence, complications, and similar keywords. Meta-analyses of single proportions, rates, and means were performed, employing random effects models and P < .05. Subgroup analysis and meta-regression were performed.

RESULTS

We included 16 studies, covering 674 patients, with follow-up ranging from 6 to 38.1 ± 29.7 months. Ischemic cause represented 490 (72.7%) patients; left ventricular ejection fraction varied from 25% ± 10% to 41.5% ± 13.8%. Dynamic mapping was used in 9 (57.1%) studies, 6 (37.5%) studies employed static techniques, and 1 (6.3%) study used a mixed approach. Procedure duration (P = .520) and complication incidence (P = .110) were similar between dynamic and static mapping modalities. The dynamic mapping subgroup exhibited significantly lower VT recurrence rate compared with the static mapping population (P < .010). This result persisted on a meta-regression model adjusted for ischemic cause and left ventricular ejection fraction, demonstrating that dynamic functional mapping was independently associated with lower recurrence rates (P = .005).

CONCLUSION

Functional mapping was demonstrated to be safe for VT ablation. Dynamic functional mapping independently associated with reduced postablation recurrence rates without significantly increasing procedure duration.

A screening for cerebral deoxygenation during VT ablations in patients with structural heart disease

BACKGROUND

Patients undergoing ventricular tachycardia (VT) ablation often present with structural heart disease (SHD) and reduced ejection fraction. Inducing VT by programmed electrical stimulation (PES) puts these patients at risk for hemodynamic instability and cerebral hypoperfusion.

OBJECTIVE

The present study screens for cerebral oxygen desaturation phases (ODPs) in patients undergoing VT ablation.

METHODS

Forty-seven patients (age 61 ± 14 years, 72% males) underwent ablation of sustained VT with simultaneous neuromonitoring using near-infrared spectroscopy (NIRS).

RESULTS

Analysis of NIRS signal identified ODPs in 29 patients (62%). ODPs were associated with a higher prevalence of ischemic heart disease (IHD) (45% vs. 11%, p = 0.024), previous VT episodes (n = 16 vs. 4, p = 0.018), and VTs inducible by PES (n = 2.4 vs. 1.2, p = 0.004). Patients with ODPs were more likely to be admitted to intensive care unit (ICU) (78% vs. 33%, p = 0.005) and had more in-hospital VT recurrences (24% vs. 0%, p = 0.034). No differences were observed in VT recurrence rates after hospital discharge (41.4% vs. 44.4%, p = 0.60) and left ventricular ejection fraction (34% vs. 38%, p = 0.567). IHD (OR: 32.837, p = 0.006), ICU admission (OR: 14.112, p = 0.013), and the number of VTs inducible at PES (OR: 2.705, p = 0.015) were independently associated with ODPs.

CONCLUSIONS

This study registers episodes of cerebral hypoperfusion in 62% of patients undergoing VT ablation and identifies IHD and the number of VTs inducible at PES as possible risk factors for these episodes.

Patient selection, ventricular tachycardia substrate delineation, and data transfer for stereotactic arrhythmia radioablation: a clinical consensus statement of the European Heart Rhythm Association of the European Society of Cardiology and the Heart Rhythm Society

Stereotactic arrhythmia radioablation (STAR) is a novel, non-invasive, and promising treatment option for ventricular arrhythmias (VAs). It has been applied in highly selected patients mainly as bailout procedure, when (multiple) catheter ablations, together with anti-arrhythmic drugs, were unable to control the VAs. Despite the increasing clinical use, there is still limited knowledge of the acute and long-term response of normal and diseased myocardium to STAR. Acute toxicity appeared to be reasonably low, but potential late adverse effects may be underreported. Among published studies, the provided methodological information is often limited, and patient selection, target volume definition, methods for determination and transfer of target volume, and techniques for treatment planning and execution differ across studies, hampering the pooling of data and comparison across studies. In addition, STAR requires close and new collaboration between clinical electrophysiologists and radiation oncologists, which is facilitated by shared knowledge in each collaborator's area of expertise and a common language. This clinical consensus statement provides uniform definition of cardiac target volumes. It aims to provide advice in patient selection for STAR including aetiology-specific aspects and advice in optimal cardiac target volume identification based on available evidence. Safety concerns and the advice for acute and long-term monitoring including the importance of standardized reporting and follow-up are covered by this document. Areas of uncertainty are listed, which require high-quality, reliable pre-clinical and clinical evidence before the expansion of STAR beyond clinical scenarios in which proven therapies are ineffective or unavailable.

Catheter ablation vs advanced therapy for patients with severe heart failure and ventricular electrical storm

BACKGROUND

Current data on outcomes of an initial strategy of catheter ablation vs advanced therapy in patients with severe heart failure (HF) and electric storm (ES) are limited.

OBJECTIVE

The purpose of this study was to evaluate the outcomes of ventricular tachycardia (VT) ablation vs left ventricular assist device (LVAD) or heart transplantation (HT) in patients with severe HF and ventricular ES.

METHODS

Patients with severe HF and ES who underwent VT ablation, LVAD, or HT between 2012 and 2022 at our medical center were reviewed. Severe HF was defined as ejection fraction ≤ 35% or presence of severe restrictive, valvular, or genetic cardiomyopathy. We assessed in-hospital adverse events and 1-year outcomes between the 2 groups.

RESULTS

Of the 73 patients, 43 (58.9%) underwent VT ablation and 30 (41.1%) received advanced therapy (21 HT (70%) and 9 LVAD (30%)). One-year survival was similar (76.7% vs 86.7%; log-rank, P = .308). However, 10 patients (23.3%) in the ablation group underwent HT during follow-up. After multivariable analysis, United Network for Organ Sharing status 1 or 2 according to VT criteria (hazard ratio 5.52; 95% confidence interval 1.27-24.12; P = .023) and early VT recurrence (hazard ratio 5.67; 95% confidence interval 1.68-19.09; P = .005) were associated with HT or mortality in patients who underwent VT ablation.

CONCLUSION

Patients with severe HF and ES who underwent VT ablation had similar overall survival to patients who directly proceeded with advanced therapy, although rates of HT were high during follow-up. Predictors of HT or mortality after catheter ablation include United Network for Organ Sharing status 1 or 2 according to VT criteria and early VT recurrence.

[Role of ventricular tachycardia ablation in patients with systolic heart failure]

Patients with systolic heart failure (HF) and structural heart disease often suffer from ventricular tachycardias (VTs), which lead to increased morbidity and mortality. Despite advancements in pharmacological therapy and the use of implantable cardioverter-defibrillators, treatment options are limited due to side effects and decreased effectiveness. Catheter ablation (CA) has emerged as a promising therapy for drug-refractory VTs, especially in patients with structural heart disease. This article reviews current knowledge on the indications, efficacy, and long-term prognosis of CA in patients with HF. Additionally, it discusses the importance of preprocedural planning, risk stratification, and emerging therapeutic strategies such as mechanical circulatory support and stereotactic arrhythmia radioablation. The complex relationship between VT and HF, as well as potential risks like acute hemodynamic decompensation, are also addressed.

Late gadolinium enhancement imaging for the prediction of ventricular tachycardia ablation outcome

BACKGROUND

Preprocedural cardiac magnetic resonance (CMR) imaging is crucial for identifying ventricular scar areas, borderline zones, and potential reentry channels. This study aimed to evaluate the impact of late gadolinium enhancement (LGE) core and borderline mass on the acute and long-term outcomes of ventricular tachycardia (VT) ablation in patients with structural heart disease (SHD).

METHODS AND RESULTS

A total of 204 consecutive patients underwent CMR before scheduled VT ablation. Of these, 38 were excluded due to incomplete LGE quantification caused by device-related imaging artifacts, and 19 had no detectable left ventricular (LV) LGE, resulting in a final cohort of 147 patients with positive LGE (median age 64 years, 57% with non-ischemic cardiomyopathy [NICM], median left ventricular ejection fraction 38%, 61% with defibrillators). Patients with ischemic cardiomyopathy (ICM) had higher LV mass (86 vs. 75 g, P = 0.005) and LGE core mass (21 vs. 12 g, P = 0.001) compared to NICM patients, while borderline LGE mass was similar (2.9 vs. 2.5 g, P = 0.240). ICM patients more frequently presented with transmural inferior scars, whereas NICM patients exhibited more diffuse, non-transmural LGE patterns, particularly in the inferolateral, inferoseptal, and anteroseptal regions. Post-ablation, 28 patients (19%) remained acutely inducible (with clinical VT in two), and 53 patients (36%) experienced VT recurrence within a 20-month follow-up period. Neither high LGE core mass nor borderline mass predicted VT inducibility or recurrence. Most patients with clinical deterioration had NICM with septal involvement.

CONCLUSION

In patients with SHD undergoing VT ablation, neither high LGE core mass nor borderline mass was predictive of postprocedural VT inducibility or recurrence.

The Relevance of the Type of Ventricular Arrhythmia in Titin-Related Dilated Cardiomyopathy: A Multicenter Study

BACKGROUND

Truncating titin variants (TTNtvs) are the most prevalent cause of inherited dilated cardiomyopathy. Occurrence of different ventricular arrhythmia (VA) subtypes, including premature ventricular complexes (PVCs), nonsustained ventricular tachycardia (NSVT), and sustained monomorphic VT (SMVT), has been reported.

OBJECTIVES

The aim of this study was to analyze the prognostic relevance of distinct VA subtypes among TTNtv carriers and their underlying arrhythmogenic substrates.

METHODS

Twenty-two TTNtv carriers referred for ablation of SMVT (n = 14) or frequent PVCs (n = 8) from 5 centers were included (mean age 56 ± 11 years; left ventricular ejection fraction 38% ± 13%; 77% male). Detailed phenotyping was performed, including Holter monitoring, cardiac imaging, and electroanatomical mapping. Patients were followed up for a median of 44 months.

RESULTS

Demographic characteristics, including age, comorbidities, and left ventricular ejection fraction, were similar. NSVTs were frequent in both groups but faster in patients with SMVT (cycle length: 350 milliseconds [Q1-Q3: 315-403 milliseconds] vs 427 milliseconds [Q1-Q3: 395-469 milliseconds]). Although substrates for SMVT extended in a basal ring-like fashion with septal predominance, PVC sites of origin were limited to the basal anterior left ventricular segment. In the SMVT group, acute complete procedural success was achieved for 36%; during follow-up, 86% had recurrent VT, and 50% died of progressive heart failure. In the PVC group, complete abolition of PVCs was achieved in only 13%; at 3 months, median PVC burden was 1%, and there were no deaths or sustained VT during follow-up. VA subtype and NSVT cycle length were associated with mortality and poor VT-free survival.

CONCLUSIONS

In TTNtv carriers, SMVTs but not frequent PVCs are associated with high mortality due to heart failure. Occurrence of SMVT may identify a subgroup at risk for rapid, progressive adverse remodeling. The prognostic significance of different VA subtypes needs to be confirmed in a larger cohort.

Ablation options for sub-epicardially located ventricular substrates responsible for ventricular tachycardia: where is it all headed?

PURPOSE OF REVIEW

Patients with nonischemic and ischemic cardiomyopathy (NICM and ICM) exhibit re-entrant tachycardias related to scar tissue in subepicardial, in addition to typical subendocardial locations. Control of ventricular arrhythmias related to these targets has remained elusive despite advances in mapping and ablation technology.

RECENT FINDINGS

Percutaneous epicardial ablation is the standard after failed endocardial ventricular ablation, but recurrence rates are disappointing. Pulsed-field energy has been associated with coronary artery spasm and therefore may be less suitable for epicardial ablation. Commercially available energy sources, including pulsed-field, have limited depths of myocardial penetration when applied epicardially. Lateral volumetric thermal spreading of ablation injury is associated with decreasing depth of ablation and is difficult to control. A new cryoablation technology based on liquid helium and developed specifically for epicardial work may be able to overcome these limitations.

SUMMARY

Ablation strategies that can improve lesion formation in subepicardial ventricular myocardium may improve outcomes of ablation in nonsubendocardial NICM and ICM targets.

Emergent Ablation for Ventricular Tachycardia: Predictors of Prolonged Hospitalization and Mortality

BACKGROUND

Patients with ventricular tachycardia (VT) frequently present in unstable VT and are subject to urgent/high-risk ablation procedures. Clinical predictors of prolonged hospitalization and mortality are needed for optimal management of these patients.

OBJECTIVES

This study seeks to identify factors associated with prolonged hospitalization and mortality in emergent unplanned VT ablation procedures.

METHODS

Fifty consecutive patients hospitalized emergently for VT with structural heart disease who underwent catheter ablation were prospectively followed up for outcomes and complications.

RESULTS

Of the 50 patients (mean age 67.6 ± 12.8 years), 86.0% were male, 62.0% had ischemic cardiomyopathy, and their median left ventricular ejection fraction was 28.5%. Hospital stay <7 days (median 3 days) occurred in 28 (56.0%) patients (Group 1) and >7 days (median 10 days) or death <7 days occurred in 22 (44.0%) patients (Group 2). PAINESD score and left ventricular ejection fraction were similar between the groups. Compared with Group 1, Group 2 had significantly worse NYHA functional class III or higher (25.0% vs 63.6%; P = 0.006), electrical storm (46.4% vs 77.3%; P = 0.027), and prior failed VT ablation (35.7% vs 68.2%; P = 0.023). Multivariable analysis showed that NYHA functional class III or higher and prior failed VT ablation were predictive of prolonged hospital stay. After ablation, compared with Group 1, Group 2 had worse heart failure (10.7% vs 54.5%; P = 0.001), VT recurrences (3.6% vs 68.2%; P < 0.001), and 7 deaths within 30 days.

CONCLUSIONS

Patients undergoing emergent VT ablation are at high risk for prolonged hospital stay, which is predicted by NYHA functional class III or higher and a prior failed ablation. Early VT recurrences and worsening heart failure contribute to prolonged hospitalization and a high 30-day mortality.

Lipomatous Metaplasia Facilitates Ventricular Tachycardia in Patients With Nonischemic Cardiomyopathy

BACKGROUND

Ventricular tachycardia (VT) substrate in patients with nonischemic cardiomyopathy (NICM) is complex in distribution and intramural location.

OBJECTIVES

This study sought to test the hypothesis that myocardial lipomatous metaplasia (LM) is a vital anatomic substrate for VT corridors in patients with NICM and VT, and that LM stabilizes current propagation in VT corridors.

METHODS

Among 49 patients with NICM in the 2-center INFINITY (Prospective Intra-Myocardial Fat Deposition and Ventricular Tachycardia in Cardiomyopathy) Study, potential VT viable corridors within the myocardial scar and/or LM were computed from late gadolinium enhancement cardiac magnetic resonance images and were registered with electroanatomical maps. Corridors passing through VT entrance, isthmus, and/or exit sites, estimated by entrainment or pace mapping, were defined as VT corridors. LM was separately distinguished from scar using computed tomography. The SD of current amplitude along each corridor was measured.

RESULTS

Compared with 151 non-VT corridors, 35 VT corridors traversed a substantially higher volume of LM, with a median 236.6 mg (IQR: 13.5-903.4 mg) vs 5.8 mg (IQR: 0.0-57.9 mg) (P < 0.001). Among corridors with computable current amplitude, 28 VT corridors exhibited substantially lower current variation along the corridors, with SD 8.0 μA (25th-75th percentile: 6.1-10.3 μA) vs 14.9 μA (25th-75th percentile: 8.5-23.7 μA) among 71 non-VT corridors (P < 0.001). Individual VT circuit sites (95 out 118) were highly colocalized with LM.

CONCLUSIONS

VT circuitry corridors in NICM are more likely to traverse LM and exhibit reduced current amplitude variation compared with bystander corridors.

One-year mortality and causes of death after stereotactic radiation therapy for refractory ventricular arrhythmias: A systematic review and pooled analysis

Patients treated with cardiac stereotactic body radiation therapy (radioablation) for refractory ventricular arrhythmias are patients with advanced structural heart disease and significant comorbidities. However, data regarding 1-year mortality after the procedure are scarce. This systematic review and pooled analysis aimed at determining 1-year mortality after cardiac radioablation for refractory ventricular arrhythmias and investigating leading causes of death in this population. MEDLINE/EMBASE databases were searched up to January 2023 for studies including patients undergoing cardiac radioablation for the treatment of refractory ventricular arrhythmias. Quality of included trials was assessed using the NIH Tool for Case Series Studies (PROSPERO CRD42022379713). A total of 1,151 references were retrieved and evaluated for relevance. Data were extracted from 16 studies, with a total of 157 patients undergoing cardiac radioablation for refractory ventricular arrhythmias. Pooled 1-year mortality was 32 % (95 %CI: 23-41), with almost half of the deaths occurring within three months after treatment. Among the 157 patients, 46 died within the year following cardiac radioablation. Worsening heart failure appeared to be the leading cause of death (52 %), although non-cardiac mortality remained substantial (41 %) in this population. Age≥70yo was associated with a significantly higher 12-month all-cause mortality (p<0.022). Neither target volume size nor radiotherapy device appeared to be associated with 1-year mortality (p = 0.465 and p = 0.199, respectively). About one-third of patients undergoing cardiac stereotactic body radiation therapy for refractory ventricular arrhythmias die within the first year after the procedure. Worsening heart failure appears to be the leading cause of death in this population.

Efficacy of balloon-expandable extreme-low-temperature ventricular epicardial cryoablation: A preclinical proof of concept evaluation

BACKGROUND

Current epicardial ablation technologies are limited by the inability to create adequate depth lesions and risk of collateral injury to extracardiac structures.

OBJECTIVE

The purpose of this study was to evaluate the feasibility and efficacy of ventricular epicardial ablation with a novel balloon-expandable extreme-low-temperature (XLT) cryoablation catheter with an embedded insulation pontoon for protection of extracardiac structures, which has been specifically designed for epicardial ablation.

METHODS

Ten healthy swine underwent surgical (n = 6) and subxiphoid percutaneous (n = 4) epicardial access. A total of 3-6 sites were targeted in the right and left ventricular wall for different exposure durations. Ablation was performed with a large footprint (surgical) and smaller footprint (percutaneous) version of the HeartPad (Corfigo Inc., Montclair, NJ) XLT system. The system consists of the balloon-expandable cryoablation catheter and a console. The console vaporizes liquid helium (-269°C) and controls continuous delivery of extremely cold helium gas at high flow rates through a high-efficiency ablation element mounted on an expandable insulation pontoon to protect extracardiac structures. Ablation lesions were assessed by gross pathology and histologic examination.

RESULTS

A total of 42 epicardial lesions were created. Mean lesion depth increased progressively with ablation time (surgical catheter: 11 ± 2 mm at ≤30 seconds, 13 ± 4 mm at 60 seconds, 15 ± 3 mm at ≥120 seconds, P = .001; percutaneous catheter: 10 ± 2 mm at 30 seconds, 14 ± 2 mm at 60 seconds, 16 ± 2 mm at 120 seconds, P = .001). Lesion geometry seemed unaffected by presence and thickness of epicardial fat. One episode of ventricular fibrillation occurred after ablation over the atrioventricular groove and 2 adjacent obtuse marginal arteries.

CONCLUSION

Surgical or percutaneous epicardial ablation using the HeartPad XLT cryoablation system is feasible and can efficiently produce deep ventricular lesions in different epicardial locations.

The Current Landscape of Ventricular Tachycardia Trials: A Systematic Review of Registered Studies

BACKGROUND

Although there are evolving techniques and technologies for treating ventricular tachycardia (VT), the current landscape of clinical trials for managing VT remains understudied.

OBJECTIVE

The objective of this study was to provide a systematic characterisation of the interventional management of VT through an analysis of the ClinicalTrials.gov, clinicaltrialsregister.eu, anzctr.org.au and chictr.org.cn databases.

METHODS

We queried all phase II to IV interventional trials registered up to November 2023 that enrolled patients with VT. Published, completed but unpublished, terminated, or ongoing trials were included for final analysis.

RESULTS

Of the 698 registered studies, 135 were related to VT, with 123 trials included in the final analysis. Among these trials, 25 (20%) have been published, enrolling a median of 35 patients (interquartile range [IQR] 20-132) over a median of 43 months (IQR 19-62). Out of the published trials, 14 (56%) were randomised, and 12 (48%) focused on catheter ablation. Twenty-two (18%) have been completed but remain unpublished, even after a median of 36 months (IQR 15-60). Furthermore, 27 (22%) trials were terminated or withdrawn, with the most common cause being poor enrolment. Currently, 49 (40%) trials are ongoing and novel non-ablative technologies, such as radioablation and autonomic modulation, account for 35% and 8% of ongoing trials, respectively.

CONCLUSIONS

Our analysis revealed that many registered trials remain unpublished or incomplete, and randomised controlled trial evidence is limited to only a few studies. Furthermore, many ongoing trials are focused on non-catheter ablation-based strategies. Therefore, larger pragmatic trials are needed to create stronger evidence in the future.

Periprocedural acute haemodynamic decompensation during substrate-based ablation of scar-related ventricular tachycardia: a rare and unpredictable event

AIMS

Patients with structural heart disease (SHD) undergoing catheter ablation (CA) for ventricular tachycardia (VT) are at considerable risk of periprocedural complications, including acute haemodynamic decompensation (AHD). The PAINESD score was proposed to predict the risk of AHD. The goal of this study was to validate the PAINESD score using the retrospective analysis of data from a large-volume heart centre.

METHODS AND RESULTS

Patients who had their first radiofrequency CA for SHD-related VT between August 2006 and December 2020 were included in the study. Procedures were mainly performed under conscious sedation. Substrate mapping/ablation was performed primarily during spontaneous rhythm or right ventricular pacing. A purposely established institutional registry for complications of invasive procedures was used to collect all periprocedural complications that were subsequently adjudicated using the source medical records. Acute haemodynamic decompensation triggered by CA procedure was defined as intraprocedural or early post-procedural (<12 h) development of acute pulmonary oedema or refractory hypotension requiring urgent intervention. The study cohort consisted of 1124 patients (age, 63 ± 13 years; males, 87%; ischaemic cardiomyopathy, 67%; electrical storm, 25%; New York Heart Association Class, 2.0 ± 1.0; left ventricular ejection fraction, 34 ± 12%; diabetes mellitus, 31%; chronic obstructive pulmonary disease, 12%). Their PAINESD score was 11.4 ± 6.6 (median, 12; interquartile range, 6-17). Acute haemodynamic decompensation complicated the CA procedure in 13/1124 = 1.2% patients and was not predicted by PAINESD score with AHD rates of 0.3, 1.8, and 1.1% in subgroups by previously published PAINESD terciles (<9, 9-14, and >14). However, the PAINESD score strongly predicted mortality during the follow-up.

CONCLUSION

Primarily substrate-based CA of SHD-related VT performed under conscious sedation is associated with a substantially lower rate of AHD than previously reported. The PAINESD score did not predict these events. The application of the PAINESD score to the selection of patients for pre-emptive mechanical circulatory support should be reconsidered.

Lipomatous Metaplasia Is Associated With Ventricular Tachycardia Recurrence Following Ablation in Patients With Nonischemic Cardiomyopathy

BACKGROUND

Ventricular tachycardia (VT) recurrence rates remain high following ablation among patients with nonischemic cardiomyopathy (NICM).

OBJECTIVES

This study sought to define the prevalence of lipomatous metaplasia (LM) in patients with NICM and VT and its association with postablation VT recurrence.

METHODS

From patients who had ablation of left ventricular VT, we retrospectively identified 113 consecutive NICM patients with preprocedural contrast-enhanced cardiac computed tomography (CECT), from which LM was segmented. Nested within this cohort were 62 patients that prospectively underwent CECT and cardiac magnetic resonance from which myocardial border zone and dense late gadolinium enhancement (LGE) were segmented. A control arm of 30 NICM patients without VT with CECT was identified.

RESULTS

LM was identified among 57% of control patients without VT vs 83% of patients without VT recurrence and 100% of patients with VT recurrence following ablation. In multivariable analyses, LM extent was the only independent predictor of VT recurrence, with an adjusted HR per 1-g LM increase of 1.1 (P < 0.001). Patients with LM extent ≥2.5 g had 4.9-fold higher hazard of VT recurrence than those with LM <2.5 g (P < 0.001). In the nested cohort with 32 VT recurrences, LM extent was independently associated with VT recurrence after adjustment for border zone and LGE extent (HR per 1 g increase: 1.1; P = 0.036).

CONCLUSIONS

Myocardial LM is prevalent in patients with NICM of a variety of etiologies, and its extent is associated with postablation VT recurrence independent of the degree of fibrosis.

Intramural needle ablation or repeated standard ablation in patients referred for repeat ablation of scar-related ventricular tachycardia

INTRODUCTION

When ventricular tachycardia (VT) recurs after standard RF ablation (sRFA) some patients benefit from repeat sRFA, whereas others warrant advanced methods such as intramural needle ablation (INA). Our objectives are to assess the utility of repeat sRFA and to clarify the benefit of INA when repeat sRFA fails in patients with VT due to structural heart disease.

METHODS

In consecutive patients who were prospectively enrolled in a study for INA for recurrent sustained monomorphic VT despite sRFA, repeat sRFA was considered first. INA was performed during the same procedure if repeat sRFA failed or no targets for sRFA were identified.

RESULTS

Of 85 patients enrolled, acute success with repeat sRFA was achieved in 30 patients (35%), and during the 6-month follow-up, 87% (20/23) were free of VT hospitalization, 78% were free of any VT, and 7 were lost to follow-up. INA was performed in 55 patients (65%) after sRFA failed, or no endocardial targets were found abolished or modified inducible VT in 35/55 patients (64%). During follow-up, 72% (39/54) were free of VT hospitalization, 41% were free of any VT, and 1 was lost to follow-up. Overall, 59 out of 77 (77%) patients were free of hospitalization and 52% were free of any VT. Septal-origin VTs were more likely to need INA, whereas RV and papillary muscle VTs were less likely to require INA.

CONCLUSIONS

Repeat sRFA was beneficial in 23% (18/77) of patients with recurrent sustained VT who were referred for INA. The availability of INA increased favorable outcomes to 52%.

Management of patients with an electrical storm or clustered ventricular arrhythmias: a clinical consensus statement of the European Heart Rhythm Association of the ESC-endorsed by the Asia-Pacific Heart Rhythm Society, Heart Rhythm Society, and Latin-American Heart Rhythm Society

Electrical storm (ES) is a state of electrical instability, manifesting as recurrent ventricular arrhythmias (VAs) over a short period of time (three or more episodes of sustained VA within 24 h, separated by at least 5 min, requiring termination by an intervention). The clinical presentation can vary, but ES is usually a cardiac emergency. Electrical storm mainly affects patients with structural or primary electrical heart disease, often with an implantable cardioverter-defibrillator (ICD). Management of ES requires a multi-faceted approach and the involvement of multi-disciplinary teams, but despite advanced treatment and often invasive procedures, it is associated with high morbidity and mortality. With an ageing population, longer survival of heart failure patients, and an increasing number of patients with ICD, the incidence of ES is expected to increase. This European Heart Rhythm Association clinical consensus statement focuses on pathophysiology, clinical presentation, diagnostic evaluation, and acute and long-term management of patients presenting with ES or clustered VA.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

Our ML models effectively predict VT recurrence post-ablation, aiding in identifying high-risk patients and tailoring follow-up strategies.

Mapping and Ablation of Ventricular Tachycardia in Inherited Left Ventricular Cardiomyopathies

Advances in the field of human genetics have led to an accumulating understanding of the genetic basis of distinct nonischemic cardiomyopathies associated with ventricular tachycardias (VTs) and sudden cardiac death. To date, there is an increasing proportion of patients with inherited cardiomyopathies requiring catheter ablation for VTs. This review provides an overview of disease-causing gene mutations frequently encountered and relevant for clinical electrophysiologists. Available data on VT ablation in patients with an inherited etiology and a phenotype of a nondilated left ventricular cardiomyopathy, dilated cardiomyopathy, or hypertrophic cardiomyopathy are summarized. VTs amenable to catheter ablation are related to nonischemic fibrosis. Recent insights into genotype-phenotype relations of subtype and location of fibrosis have important implications for treatment planning. Current strategies to delineate nonischemic fibrosis and related arrhythmogenic substrates using multimodal imaging, image integration, and electroanatomical mapping are provided. The ablation approach depends on substrate location and extension. Related procedural aspects including patient-tailored (enhanced) ablation strategies and outcomes are outlined. Challenging substrates for VT and the underlying inherited etiologies with a high risk for rapid progressive heart failure contribute to poor outcomes after catheter ablation. Electroanatomical data obtained during ablation may allow the identification of patients at particular risk who need to be considered for early work-up for left ventricular assist device implantation or heart transplantation.

Spotlight on the 2022 ESC guideline management of ventricular arrhythmias and prevention of sudden cardiac death: 10 novel key aspects

Sudden cardiac death and ventricular arrhythmias are a global health issue. Recently, a new guideline for the management of ventricular arrhythmias and prevention of sudden cardiac death has been published by the European Society of Cardiology that serves as an update to the 2015 guideline on this topic. This review focuses on 10 novel key aspects of the current guideline: As new aspects, public basic life support and access to defibrillators are guideline topics. Recommendations for the diagnostic evaluation of patients with ventricular arrhythmias are structured according to frequently encountered clinical scenarios. Management of electrical storm has become a new focus. In addition, genetic testing and cardiac magnetic resonance imaging significantly gained relevance for both diagnostic evaluation and risk stratification. New algorithms for antiarrhythmic drug therapy aim at improving safe drug use. The new recommendations reflect increasing relevance of catheter ablation of ventricular arrhythmias, especially in patients without structural heart disease or stable coronary artery disease with only mildly impaired ejection fraction and haemodynamically tolerated ventricular tachycardias. Regarding sudden cardiac death risk stratification, risk calculators for laminopathies, and long QT syndrome are now considered besides the already established risk calculator for hypertrophic cardiomyopathy. Generally, 'new' risk markers beyond left ventricular ejection fraction are increasingly considered for recommendations on primary preventive implantable cardioverter defibrillator therapy. Furthermore, new recommendations for diagnosis of Brugada syndrome and management of primary electrical disease have been included. With many comprehensive flowcharts and practical algorithms, the new guideline takes a step towards a user-oriented reference book.

Electrical storm management in structural heart disease

Electrical storm (ES) is a life-threatening condition characterized by at least three separate episodes of ventricular arrhythmias (VAs) over 24 h, each requiring therapeutic intervention, including implantable cardioverter defibrillator (ICD) therapies. Patients with ICDs in secondary prevention are at higher risk of ES and the most common presentation is that of scar-related monomorphic VAs. Electrical storm represents a major unfavourable prognostic marker in the history of patients with structural heart disease, with an associated two- to five-fold increase in mortality, heart transplant, and heart failure hospitalization. Early recognition and prompt treatment are crucial to improve the outcome. Yet, ES management is complex and requires a multidisciplinary approach and well-defined protocols and networks to guarantee a proper patient care. Acute phase stabilization should include a comprehensive clinical assessment, resuscitation and sedation management skills, ICD reprogramming, and acute sympathetic modulation, while the sub-acute/chronic phase requires a comprehensive heart team evaluation to define the better treatment option according to the haemodynamic and overall patient's condition and the type of VAs. Advanced anti-arrhythmic strategies, not mutually exclusive, include invasive ablation, cardiac sympathetic denervation, and, for very selected cases, stereotactic ablation. Each of these aspects, as well as the new European Society of Cardiology guidelines recommendations, will be discussed in the present review.

[The new ESC guidelines on the management of ventricular tachyarrhythmias : Implications for daily practice]

The recently published guidelines of the European Society of Cardiology (ESC) on the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death is an update of the 2015 guideline. For the first time a new section is dedicated to public basic life support. In the acute treatment of ventricular arrhythmias electrical cardioversion is upgraded, and there is a new focus on the management of electrical storm. Recommendations for the comprehensive diagnostic evaluation of patients with first manifestations of ventricular arrhythmias structured according to common clinical scenarios are also new. Both genetic testing and cardiac magnetic resonance imaging are upgraded, not only for diagnostic evaluation but also for risk stratification. In the long-term management, recommendations for pharmacotherapy are aligned with current heart failure guidelines. Catheter ablation has gained relevance not only for recurrent ventricular tachycardia under amiodarone treatment and as an alternative to implantable cardioverter defibrillation (ICD) implantation in selected patients with coronary artery disease but also particularly in the treatment of idiopathic ventricular extrasystoles and tachycardia. The ICD treatment remains an essential component of primary and secondary prevention of sudden cardiac death. Of note, the recommendation on primary preventive ICD treatment for patients with dilated cardiomyopathy and left ventricular ejection fraction (LVEF) ≤ 35% has been downgraded. In addition to LVEF a combination of risk factors and risk calculators is included in the recommendations on primary prophylactic ICD implantation. Overall, due to numerous tables and practical algorithms, the guidelines have become a user-oriented reference book.

One-year outcomes in cardiogenic shock triggered by ventricular arrhythmia: An analysis of the FRENSHOCK multicenter prospective registry

Background

Cardiogenic shock (CS) is a life-threatening condition carrying poor prognosis, potentially triggered by ventricular arrhythmia (VA). Whether the occurrence of VA as trigger of CS worsens the prognosis compared to non-VA triggers  remains  unclear.  The  aim  of  this  study  was  to  evaluate  1-year  outcomes [mortality, heart transplantation, ventricular assist devices (VAD)] between VA-triggered and non-VA-triggered CS.

Methods

FRENSHOCK is a prospective multicenter registry including 772 CS patients from 49 centers. One to three triggers can be identified in the registry (ischemic, mechanical complications, ventricular/supraventricular arrhythmia, bradycardia, iatrogenesis, infection, non-compliance). Baseline characteristics, management and 1-year outcomes were analyzed according to the VA-trigger in the CS population.

Results

Within 769 CS patients included, 94 were VA-triggered (12.2%) and were compared to others. At 1 year, although there was no mortality difference [42.6 vs. 45.3%, HR 0.94 (0.67-1.30), p = 0.7], VA-triggered CS resulted in more heart transplantations and VAD (17 vs. 9%, p = 0.02). Into VA-triggered CS group, though there was no 1-year mortality difference between ischemic and non-ischemic cardiomyopathies [42.5 vs. 42.6%, HR 0.97 (0.52-1.81), p = 0.92], non-ischemic cardiomyopathy led to more heart transplantations and VAD (25.9 vs. 5%, p = 0.02).

Conclusion

VA-triggered CS did not show higher mortality compared to other triggers but resulted in more heart transplantation and VAD at 1 year, especially in non-ischemic cardiomyopathy, suggesting the need for earlier evaluation by advanced heart failure specialized team for a possible indication of mechanical circulatory support or heart transplantation.

Clinical trial registration

https://clinicaltrials.gov, identifier NCT02703038.

Prognostic Impact of Different Types of Ventricular Tachyarrhythmias Stratified by Underlying Cardiac Disease

Limited data regarding the outcome of patients with different types of ventricular tachyarrhythmias is available. This study sought to assess the prognostic impact of different types of ventricular tachyarrhythmias stratified by underlying cardiac disease. A large retrospective registry was used including all consecutive patients presenting with ventricular tachycardia (VT) and fibrillation (VF) on admission from 2002 to 2016. Patients with non-sustained VT (ns-VT), sustained VT (s-VT) and VF were compared using uni- and multivariable Cox regression models. Risk stratification was performed after stratification by underlying cardiac disease (i.e., acute myocardial infarction (AMI), ischemic heart disease (IHD), non-ischemic cardiomyopathy (NICM) and patients considered as lower-risk for ventricular tachyarrhythmias). The primary endpoint was defined as all-cause mortality at 2.5 years. Secondary endpoints were cardiac death at 24 h, all-cause mortality at 5 years, cardiac rehospitalization and a composite arrhythmic endpoint at 2.5 years. In 2422 consecutive patients with ventricular tachyarrhythmias, most patients were admitted with VF (44%), followed by ns-VT (30%) and s-VT (26%). Patients with VF suffered most commonly from AMI (42%), whereas heart failure was more common in s-VT patients (32%). In patients with AMI (HR = 1.146; 95% CI 0.751-1.750; p = 0.527) and in the lower-risk group (HR = 1.357; 95% CI 0.702-2.625; p = 0.364), the risk of all-cause mortality did not differ in VF and s-VT patients. In IHD patients, VF was associated with impaired prognosis compared to s-VT (HR = 2.502; 95% CI 1.936-3.235; p = 0.001). In conclusion, VF was associated with worse long-term prognosis compared to s-VT in IHD patients, whereas the risk of all-cause mortality among VF and s-VT patients did not differ in patients with AMI, NICM and in patients considered at lower risk for ventricular tachyarrhythmias.

[From premature ventricular complexes to sustained ventricular tachycardia : An overview of innovations in the 2022 ESC Guideline on the therapy of ventricular arrhythmias]

The recent 2022 European Society of Cardiology Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death are an update of the former 2015 European guidelines. With multiple tables, algorithms, and comprehensive integration of underlying study data, the new guideline is a user-oriented reference book for clinical practice that also covers special clinical situations such as cardiac arrhythmias in pregnancy or in the context of sports. Regarding the acute treatment of ventricular arrhythmias, cardioversion is now recommended in case of hemodynamically tolerated arrhythmias. Beyond that, the guideline places special emphasis on the management of the electrical storm. In long-term therapy, recommendations for drug therapy have been aligned with current heart failure guidelines. Catheter ablation of ventricular arrhythmias has gained importance not only for recurrent ventricular tachycardia under chronic amiodarone therapy and as an alternative to implantable cardioverter-defibrillators (ICDs) in selected patients with coronary artery disease, but especially for the treatment of idiopathic premature ventricular contractions and tachycardias. Risk stratification and criteria for primary preventive ICDs are still controversial topics, which are discussed in detail based on the specific disease entities.