Clinical features and outcomes in carriers of pathogenic desmoplakin variants.

BACKGROUND AND AIMS: Pathogenic variants in the desmoplakin (DSP) gene are associated with the development of a distinct arrhythmogenic cardiomyopathy phenotype not fully captured by either dilated cardiomyopathy (DCM), non-dilated left ventricular cardiomyopathy (NDLVC), or arrhythmogenic right ventricular cardiomyopathy (ARVC). Prior studies have described baseline DSP cardiomyopathy genetic, inflammatory, and structural characteristics. However, cohort sizes have limited full clinical characterization and identification of clinical and demographic predictors of sustained ventricular arrhythmias (VAs), heart failure (HF) hospitalizations, and transplant/death. In particular, the relevance of acute myocarditis-like episodes for subsequent disease course is largely unknown. METHODS: All patients with pathogenic/likely pathogenic (P/LP) DSP variants in the worldwide DSP-ERADOS Network (26 academic institutions across nine countries) were included. The primary outcomes were the development of sustained VA and HF hospitalizations during follow-up. Fine-Gray regressions were used to test association between clinical and instrumental parameters and the development of outcomes. RESULTS: Eight hundred patients [40.3 ± 17.5 years, 47.5% probands, left ventricular ejection fraction (LVEF) 49.5 ± 13.9%] were included. Over 3.7 [1.4-7.1] years, 139 (17.4%, 3.9%/year) and 72 (9.0%, 1.8%/year) patients experienced sustained VA and HF episodes, respectively. A total of 32.5% of individuals did not fulfil diagnostic criteria for ARVC, DCM, or NDLVC; their VA incidence was 0.5%/year. In multivariable regression, risk features associated with the development of VA were female sex [adjusted hazard ratio (aHR) 1.547; P = .025], prior non-sustained ventricular tachycardia (aHR 1.721; P = .009), prior sustained VA (aHR 1.923; P = .006), and LVEF ≤ 50% (aHR: 1.645; P = .032), while for HF, they were the presence of T-wave inversion in 3+ electrocardiogram leads (aHR 2.036, P = .007) and LVEF ≤ 50% (aHR 3.879; P < .001). Additionally, 70 (8.8%) patients experienced a myocardial injury episode at presentation or during follow-up. These episodes were associated with an increased risk of VA and HF thereafter (HR 2.394; P < .001, and HR 5.064, P < .001, respectively). CONCLUSIONS: Patients with P/LP DSP variants experience high rates of sustained VA and HF hospitalizations. These patients demonstrate a distinct clinical phenotype (DSP cardiomyopathy), whose most prominent risk features associated with adverse clinical outcomes are the presence of prior non-sustained ventricular tachycardia or sustained VA, T-wave inversion in 3+ leads on electrocardiogram, LVEF ≤ 50%, and myocardial injury events.

Prediction of Major Arrhythmic Outcomes in Ischemic Cardiomyopathy: Value of Hibernating Myocardium in PET/CT.

AIMS: Known predictors of major arrhythmic events (MAE) in patients with ischemic cardiomyopathy (ICM) include previous MAE and left ventricular ejection fraction (LVEF) ≤35%. Myocardial scars detected by perfusion imaging in ICM have been linked to MAE, but the prognostic significance of hibernating myocardium (HM) is unclear. The objective was to predict major arrhythmic events (MAE) from combined 13N-ammonia (NH3) and 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in ischemic cardiomyopathy (ICM). METHODS AND RESULTS: Consecutive patients with ICM undergoing combined NH3- and FDG-PET/CT were included. HM was quantified in relation to total left ventricular myocardium (i.e. ≥7% is large). The primary outcome was MAE (sudden cardiac death, ICD therapy, sustained ventricular tachycardia/fibrillation).Among 254 patients, median baseline LVEF was 35% (IQR 28-45) and 10% had an ICD. PET/CT identified ischemia in 94 (37%), scar in 229 (90%) and HM in 195 (77%) patients. Over a median follow-up of 5.4 (IQR 2.2-9.5) years, MAE occurred in 34 patients (13%). Large HM was associated with a lower incidence of MAE (HR 0.31, 95% CI 0.1-0.8, p=0.001). After multivariate adjustment for history of MAE, LVEF ≤35% and scar ≥10%, large HM remained significantly associated with a lower incidence of MAE (p=0.016). LVEF improved over time among patients with large HM (p=0.006) but did not change in those without (p=0.610) or small HM (p=0.240). CONCLUSIONS: HM conveys a lower risk of MAE in patients with ICM. This may be explained by an increase in LVEF when a large extent of HM is present.

A novel tool for arrhythmic risk stratification in desmoplakin gene variant carriers.

BACKGROUND AND AIMS: Pathogenic desmoplakin (DSP) gene variants are associated with the development of a distinct form of arrhythmogenic cardiomyopathy known as DSP cardiomyopathy. Patients harbouring these variants are at high risk for sustained ventricular arrhythmia (VA), but existing tools for individualized arrhythmic risk assessment have proven unreliable in this population. METHODS: Patients from the multi-national DSP-ERADOS (Desmoplakin SPecific Effort for a RAre Disease Outcome Study) Network patient registry who had pathogenic or likely pathogenic DSP variants and no sustained VA prior to enrolment were followed longitudinally for the development of first sustained VA event. Clinically guided, step-wise Cox regression analysis was used to develop a novel clinical tool predicting the development of incident VA. Model performance was assessed by c-statistic in both the model development cohort (n = 385) and in an external validation cohort (n = 86). RESULTS: In total, 471 DSP patients [mean age 37.8 years, 65.6% women, 38.6% probands, 26% with left ventricular ejection fraction (LVEF) < 50%] were followed for a median of 4.0 (interquartile range: 1.6-7.3) years; 71 experienced first sustained VA events {2.6% [95% confidence interval (CI): 2.0, 3.5] events/year}. Within the development cohort, five readily available clinical parameters were identified as independent predictors of VA and included in a novel DSP risk score: female sex [hazard ratio (HR) 1.9 (95% CI: 1.1-3.4)], history of non-sustained ventricular tachycardia [HR 1.7 (95% CI: 1.1-2.8)], natural logarithm of 24-h premature ventricular contraction burden [HR 1.3 (95% CI: 1.1-1.4)], LVEF < 50% [HR 1.5 (95% CI: .95-2.5)], and presence of moderate to severe right ventricular systolic dysfunction [HR 6.0 (95% CI: 2.9-12.5)]. The model demonstrated good risk discrimination within both the development [c-statistic .782 (95% CI: .77-.80)] and external validation [c-statistic .791 (95% CI: .75-.83)] cohorts. The negative predictive value for DSP patients in the external validation cohort deemed to be at low risk for VA (<5% at 5 years; n = 26) was 100%. CONCLUSIONS: The DSP risk score is a novel model that leverages readily available clinical parameters to provide individualized VA risk assessment for DSP patients. This tool may help guide decision-making for primary prevention implantable cardioverter-defibrillator placement in this high-risk population and supports a gene-first risk stratification approach.

Predictors of ventricular tachyarrhythmia in patients with a wearable cardioverter defibrillator: an international multicenter registry.

BACKGROUND AND AIMS: Wearable cardioverter defibrillator (WCD) can protect patients from sudden cardiac death due to ventricular tachyarrhythmias and serve as a bridge to decision of definite defibrillator implantation. The aim of this analysis from an international, multicenter WCD registry was to identify predictors of sustained ventricular tachycardia (VT) and/or ventricular fibrillation (VF) in this population. METHODS: One thousand six hundred seventy-five patients with WCD were included in a multicenter registry from 9 European centers, with a median follow-up of 440 days (IQR 120-893). The primary study end point was the occurrence of sustained VT/VF. RESULTS: Sustained VT was detected by WCD in 5.4% and VF in 0.9% of all patients. Of the 30.3% of patients receiving ICD implantation during follow-up, sustained VT was recorded in 9.3% and VF in 2.6%. Non-ischemic cardiomyopathy (HR 0.5, p < 0.001), and medication with angiotensin-converting enzyme inhibitors (HR 0.7, p = 0.027) and aldosterone antagonists (HR 0.7, p = 0.005) were associated with a significantly lower risk of VT/VF. CONCLUSIONS: Patients who received WCD due to a transient increased risk of sudden cardiac death have a comparatively lower risk of VT/VF in the presence of non-ischemic cardiomyopathy. Of note, optimal medical treatment for heart failure not only results in an improvement in left ventricular ejection fraction but also in a reduction in the risk for VT/VF.

No beneficial use of the wearable cardioverter defibrillator among patients suffering from inherited and congenital heart disease: data from a European multicenter registry.

Background: Data on the use of the wearable cardioverter defibrillator in patients suffering from inherited and congenital heart disease are limited. Consequently, evidence for guideline recommendations in this patient population is lacking. Methods: In total 1,675 patients were included in a multicenter registry of eight European centers. In the present cohort, we included 18 patients suffering from congenital and inherited heart disease. Results: Nine patients (50%) were male with a mean age of 41.3 ± 16.4 years. Four patients suffered from hypertrophic cardiomyopathy (HCM), four patients suffered from non-compaction cardiomyopathy (NCCM), two patients were diagnosed with arrhythmogenic right ventricular cardiomyopathy (ARVC) and one patient suffered from muscular dystrophy of the limb-girdle type with cardiac involvement, secondary cardiomyopathy. Three patients presented with Brugada syndrome (BrS). One patient suffered from long-QT syndrome type 1 (LQTS1). Furthermore, two patients had congenital heart defects and one patient suffered from cardiac sarcoidosis (CS). There were no appropriate/inappropriate shocks with the WCD in this cohort. One patient had recurrent self-limiting sustained ventricular tachycardia during the wear time, but actively inhibited a shock and was hospitalized. The compliance rate in this cohort was 77.8% with a mean wear time of 45.3 ± 26.9 days with a mean follow-up time of 570 ± 734 days. 55.6% (10/18) of the patients received an ICD after WCD wear time. Conclusions: This retrospective study of patients with inherited and congenital heart disease shows that WCD use is not beneficial in the majority of patients with inherited and congenital heart disease.

Long-Term Arrhythmic Follow-Up and Risk Stratification of Patients With Desmoplakin-Associated Arrhythmogenic Right Ventricular Cardiomyopathy.

Background: Patients with likely pathogenic/pathogenic desmoplakin (DSP) variants are poorly characterized. Some of them meet diagnostic criteria for arrhythmogenic right ventricular cardiomyopathy (ARVC), but it is unclear how risk stratification strategies for ARVC perform in this setting. Objectives: The purpose of this study was to characterize arrhythmic outcomes and to test the performance of the recently validated ARVC risk calculator in patients with DSP likely pathogenic/pathogenic variants fulfilling definite 2010 ARVC Task Force Criteria (DSP-TFC+). Methods: DSP-TFC+ patients were enrolled from 20 institutions across 3 continents. Ventricular arrhythmias (VA), defined as a composite of sustained ventricular tachycardia (VT), appropriate implantable cardioverter defibrillator therapies, and ventricular fibrillation/sudden cardiac death events in follow-up, were reported as the primary outcome. We tested the performance of the ARVC risk calculator for VA prediction, reporting c-statistics. Results: Among 252 DSP-TFC+ patients (age 39.6 ± 16.9 years, 35.3% male), 94 (37.3%) experienced VA over 44.5 [IQR: 19.6-78.3] months. Patients with left ventricle involvement (n = 194) were at higher VA risk (log-rank P = 0.0239). History of nonsustained VT (aHR 2.097; P = 0.004) showed the strongest association with VA occurrence during the first 5-year follow-up. Neither age (P = 0.723) nor male sex (P = 0.200) was associated with VAs at follow-up. In 204 patients without VA at diagnosis, incident VA rate was high (32.8%; 7.37%/y). The ARVC risk calculator performed poorly overall (c-statistic 0.604 [0.594-0.614]) and very poorly in patients with left ventricular disease (c-statistic 0.558 [0.556-0.560]). Conclusions: DSP-TFC+ patients are at substantial risk for VAs. The ARVC risk calculator performs poorly in DSP-TFC+ patients suggesting need for a gene-specific risk algorithm. Meanwhile, DSP-TFC+ patients with nonsustained VT should be considered as high-risk.

Rhythm vs Rate Control Strategy for Atrial Fibrillation: A Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Rhythm control, either with antiarrhythmic drugs or catheter ablation, and rate control strategies are the cornerstones of atrial fibrillation (AF) management. Despite the increasing role of rhythm control over the past few years, it remains inconclusive which strategy is superior in improving clinical outcomes. OBJECTIVES: This study summarizes the total and time-varying evidence regarding the efficacy of rhythm- vs rate-control strategies in the management of AF. METHODS: We systematically perused the MEDLINE, CENTRAL (Cochrane Central Register of Controlled Trials), and Web of Science databases for randomized controlled trials from inception to November 2023. We included studies that compared the efficacy of rhythm control (ie, antiarrhythmic drugs classes Ia, Ic, or III, AF catheter ablation, and electrical cardioversion) and rate control (ie, beta-blocker, digitalis, or calcium antagonist) strategies among patients with nonvalvular AF. The primary outcome was cardiovascular (CV) death, whereas secondary outcomes included all-cause death, stroke, hospitalization for heart failure (HF), sinus rhythm at the end of the follow-up, and rhythm control-related adverse events. A cumulative meta-analysis to assess temporal trends and a meta-regression analysis using the percentage of ablation use was performed. RESULTS: We identified 18 studies with a total of 17,536 patients (mean age: 68.6 ± 9.7 years, 37.9% females) and a mean follow-up of 28.5 months. Of those, 31.9% had paroxysmal AF. A rhythm control strategy reduced CV death (HR: 0.78; 95% CI: 0.62-0.96), stroke (HR: 0.801; 95% CI: 0.643-0.998), and hospitalization for HF (HR: 0.80; 95% CI: 0.69-0.94) but not all-cause death (HR: 0.86; 95% CI: 0.73-1.02) compared with a rate control strategy. This benefit was driven by contemporary studies, whereas more ablation use within the rhythm control arm was associated with improved outcomes, except stroke. CONCLUSIONS: In patients with AF, a contemporary rhythm control strategy leads to reduced CV mortality, HF events, and stroke compared with a rate control strategy.

Leadless Pacemaker Implantation in Patients With a Prior Conventional Pacing System.

Background: Leadless pacing has been established as an alternative approach to transvenous devices for selected patients. Often, leadless pacemaker (LP) implantation is a de novo procedure, but in an increasing number of patients, an LP is used after previous implantation of a conventional pacing system (CPS). Methods: A retrospective analysis was conducted of the efficacy and safety of LP implantation in the context of a previously implanted CPS, from 2 large Swiss centres. Results: A total of 257 consecutive patients undergoing LP implantation were included. They were divided into 2 groups: group 1 consisted of 233 patients who did not have a previous CPS, and group 2 consisted of 24 patients with an in situ CPS. In group 2, a total of 20 patients (83%) required transvenous lead extraction due to infection, malfunction, or other reasons. In 3 patients with device-related infection, lead extraction and LP implantation was performed as a single procedure, whereas in the remaining 11 cases, a time window occurred between the 2 procedures (median: 11.5 days; range: 2-186 days). Electrical device parameters at implantation and during follow-up did not differ between the 2 groups (mean: 12.5 ± 9.3 months). Eight major periprocedural complications (3.1%) were encountered (4 pericardial effusions, 3 instances of femoral bleeding, and 1 instance of intra-abdominal bleeding) in the entire cohort within a 30-day period. No complications occurred in the group with a previous device. No infections were registered, even when complete extraction of an infected CPS was performed prior to LP implantation. Conclusions: Implantation of an LP in patients with a prior CPS (with or without extraction of the previous system) was effective and safe in our population of patients.

Contexte: La stimulation cardiaque sans fil a été établie comme une solution de substitution aux dispositifs transveineux chez certains patients. L'implantation d'un stimulateur cardiaque sans fil est souvent une intervention de novo, mais chez un nombre croissant de patients, ce type de stimulateur est utilisé après l'implantation d'un stimulateur classique. Méthodologie: Une analyse rétrospective de l'efficacité et de l'innocuité de la stimulation cardiaque sans fil dans le contexte de l'implantation d'un stimulateur classique a été réalisée dans deux grands centres suisses. Résultats: Un total de 257 patients consécutifs ayant subi l'implantation d'un stimulateur cardiaque sans fil ont été inclus. Les patients étaient répartis dans deux groupes; le groupe 1 était composé de 233 patients non porteurs d'un stimulateur classique, et le groupe 2, de 24 patients porteurs d'un stimulateur classique in situ. Dans le groupe 2, 20 patients au total (83 %) ont eu besoin d'une extraction de la sonde transveineuse en raison d'une infection, d'un défaut de fonctionnement, ou pour d'autres motifs. Chez 3 patients présentant une infection liée au stimulateur, l'extraction de la sonde et l'implantation d'un stimulateur cardiaque sans fil ont été réalisées simultanément, tandis que dans les 11 autres cas, il s'est écoulé un temps médian de 11,5 jours entre les deux interventions (min.-max. : 2-186 jours). Les paramètres relatifs au dispositif électrique au moment de l'implantation et pendant le suivi n'étaient pas différents entre les deux groupes (moyenne : 12,5 ± 9,3 mois). Huit complications périopératoires importantes (3,1 %) sont survenues (4 cas d'épanchement péricardique, 3 cas d'hémorragie fémorale et 1 cas d'hémorragie intra-abdominale) dans l'ensemble de la cohorte au cours d'une période de 30 jours. Aucune complication ne s'est produite dans le groupe de patients porteurs d'un stimulateur classique. On n'a enregistré aucun cas d'infection, même lorsque l'extraction complète du stimulateur classique infecté a été effectuée avant l'implantation du stimulateur cardiaque sans fil. Conclusions: L'implantation d'un stimulateur cardiaque sans fil chez les patients porteurs d'un stimulateur classique (avec ou sans extraction de ce stimulateur) était une intervention efficace et sûre dans cette population de patients.

Right heart strain in arrhythmogenic right ventricular cardiomyopathy: implications for cardiovascular outcome.

AIMS: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is characterized by progressive myocardial dysfunction and associated with an increased risk of major cardiovascular (CV) events. To determine right heart strain (ventricular and atrial global longitudinal strain (RVGLS and RAGLS) in patients with definite ARVC and its association with adverse events during follow-up. METHODS AND RESULTS: RVGLS and RAGLS were analysed in focused right heart apical views from 70 patients using TomTec ImageArena and association with a composite endpoint was determined (sustained ventricular arrhythmia and cardiovascular death). Over a median follow-up duration of 4.9 years, 26 (37%) patients met the endpoint. RVGLS was significantly impaired in the event group (-11.5 [-13.3 to -10.2] %) vs. the no-event group (-15.8 [-17.1 to -14.5] %, P < 0.001), and so was RAGLS (22.8 [21.4-27.4] % vs. 31.5 [25.1-39.6] %, respectively, P < 0.001). In Cox regression, RVGLS (HR 1.36, P < 0.001) and RAGLS (HR 0.92, P = 0.002) were associated with a higher risk of adverse events. In multivariable Cox regression models, RVGLS and RAGLS remained independent of and were incremental to age, gender, and conventional RV parameters, and model fitness was improved when RVGLS and RAGLS were applied together rather than alone. CONCLUSION: RVGLS and RAGLS are more impaired in patients with adverse events and associated with adverse events independent of age, gender, and conventional RV parameters. When RVGLS and RAGLS are applied together, prediction models are improved suggesting that right heart strain may form part of the echocardiographic routine protocol in patients with ARVC.

Stereotactic arrhythmia radioablation and its implications for modern cardiac electrophysiology: results of an EHRA survey.

Stereotactic arrhythmia radioablation (STAR) is a treatment option for recurrent ventricular tachycardia/fibrillation (VT/VF) in patients with structural heart disease (SHD). The current and future role of STAR as viewed by cardiologists is unknown. The study aimed to assess the current role, barriers to application, and expected future role of STAR. An online survey consisting of 20 questions on baseline demographics, awareness/access, current use, and the future role of STAR was conducted. A total of 129 international participants completed the survey [mean age 43 ± 11 years, 25 (16.4%) female]. Ninety-one (59.9%) participants were electrophysiologists. Nine participants (7%) were unaware of STAR as a therapeutic option. Sixty-four (49.6%) had access to STAR, while 62 (48.1%) had treated/referred a patient for treatment. Common primary indications for STAR were recurrent VT/VF in SHD (45%), recurrent VT/VF without SHD (7.8%), or premature ventricular contraction (3.9%). Reported main advantages of STAR were efficacy in the treatment of arrhythmias not amenable to conventional treatment (49%) and non-invasive treatment approach with overall low expected acute and short-term procedural risk (23%). Most respondents have foreseen a future clinical role of STAR in the treatment of VT/VF with or without underlying SHD (72% and 75%, respectively), although only a minority expected a first-line indication for it (7% and 5%, respectively). Stereotactic arrhythmia radioablation as a novel treatment option of recurrent VT appears to gain acceptance within the cardiology community. Further trials are critical to further define efficacy, patient populations, as well as the appropriate clinical use for the treatment of VT.

Impact of ventricular tachycardia ablation in subcutaneous implantable cardioverter defibrillator carriers: a multicentre, international analysis from the iSUSI project.

AIMS: Catheter ablation (CA) of ventricular tachycardia (VT) has become an important tool to improve clinical outcomes in patients with appropriate transvenous implantable cardioverter defibrillator (ICD) shocks. The aim of our analysis was to test whether VT ablation (VTA) impacts long-term clinical outcomes even in subcutaneous ICD (S-ICD) carriers. METHODS AND RESULTS: International Subcutaneous Implantable Cardioverter Defibrillator (iSUSI) registry patients who experienced either an ICD shock or a hospitalization for monomorphic VT were included in this analysis. Based on an eventual VTA after the index event, patients were divided into VTA+ vs. VTA- cohorts. Primary outcome of the study was the occurrence of a combination of device-related appropriate shocks, monomorphic VTs, and cardiovascular mortality. Secondary outcomes were addressed individually. Among n = 1661 iSUSI patients, n = 211 were included: n = 177 experiencing ICD shocks and n = 34 hospitalized for VT. No significant differences in baseline characteristics were observed. Both the crude and the yearly event rate of the primary outcome (5/59 and 3.8% yearly event rate VTA+ vs. 41/152 and 16.4% yearly event rate in the VTA-; log-rank: P value = 0.0013) and the cardiovascular mortality (1/59 and 0.7% yearly event rate VTA+ vs. 13/152 and 4.7% yearly event rate VTA-; log-rank P = 0.043) were significantly lower in the VTA + cohort. At multivariate analysis, VTA was the only variable remaining associated with a lower incidence of the primary outcome [adjusted hazard ratio 0.262 (0.100-0.681), P = 0.006]. CONCLUSION: In a real-world registry of S-ICD carriers, the combined study endpoint of arrhythmic events and cardiovascular mortality was lower in the patient cohort undergoing VTA at long-term follow-up. CLINICALTRIALS.GOV IDENTIFIER: NCT0473876.

PBX/Knotted 1 homeobox-2 (PKNOX2) is a novel regulator of myocardial fibrosis.

Much effort has been made to uncover the cellular heterogeneities of human hearts by single-nucleus RNA sequencing. However, the cardiac transcriptional regulation networks have not been systematically described because of the limitations in detecting transcription factors. In this study, we optimized a pipeline for isolating nuclei and conducting single-nucleus RNA sequencing targeted to detect a higher number of cell signal genes and an optimal number of transcription factors. With this unbiased protocol, we characterized the cellular composition of healthy human hearts and investigated the transcriptional regulation networks involved in determining the cellular identities and functions of the main cardiac cell subtypes. Particularly in fibroblasts, a novel regulator, PKNOX2, was identified as being associated with physiological fibroblast activation in healthy hearts. To validate the roles of these transcription factors in maintaining homeostasis, we used single-nucleus RNA-sequencing analysis of transplanted failing hearts focusing on fibroblast remodelling. The trajectory analysis suggested that PKNOX2 was abnormally decreased from fibroblast activation to pathological myofibroblast formation. Both gain- and loss-of-function in vitro experiments demonstrated the inhibitory role of PKNOX2 in pathological fibrosis remodelling. Moreover, fibroblast-specific overexpression and knockout of PKNOX2 in a heart failure mouse model induced by transverse aortic constriction surgery significantly improved and aggravated myocardial fibrosis, respectively. In summary, this study established a high-quality pipeline for single-nucleus RNA-sequencing analysis of heart muscle. With this optimized protocol, we described the transcriptional regulation networks of the main cardiac cell subtypes and identified PKNOX2 as a novel regulator in suppressing fibrosis and a potential therapeutic target for future translational studies.

Real World Data from Catheter Ablation of Ventricular Tachycardias and Premature Ventricular Complexes in a Tertiary Care Center.

Background: Catheter ablation in patients with ventricular arrhythmias (VA), such as ventricular tachycardias (VT) or frequent premature ventricular complexes (PVC), is increasingly considered an effective and safe therapy when performed in experienced centers. This study sought to determine acute success rates and complication rates of ablation procedures for patients with VA in a Swiss tertiary care center. Methods: All patients who underwent ablation therapy for VT and PVC at the University Heart Center in Zurich, Switzerland, between March 2012 and April 2017 were included in this analysis. Results: A total of 120 patients underwent catheter ablation for VT and PVC (69 and 51, respectively). Seventy percent of patients were male, and the mean age was 55.3 years. The most common indication for ablation was high PVC burden (47.5%), followed by paroxysmal VT (38.3%), ICD shocks (23.3%), incessant VT (12.5%), electrical storm (7.5%), and syncope (3.3%). Acute success rates for VT and PVC ablations were 94.2% and 92.2%, respectively. Rates for complications (including major and minor) for VT and PVC were 10.1% and 7.8%, respectively. Complications occurred only in patients with structural heart disease; no complications were noted in structurally normal hearts. Conclusions: Our results suggest that catheter ablation for VT and PVC has high acute success rates with a reasonable risk for complications in the setting of tertiary care centers, comparable to those reported in other studies.

Leadless Pacemaker Implantation, Focusing on Patients With Conduction System Disorders Post-Transcatheter Aortic Valve Replacement: A Retrospective Analysis.

Background: Impairment of the conduction system is a common complication of transcatheter aortic valve replacement (TAVR), which is typically performed in elderly patients. A leadless pacemaker (LP) may be a suitable option in this frail population, but the available scientific data concerning the efficacy and safety of leadless pacing after TAVR are sparse. The purpose of this analysis was to evaluate the efficacy and safety of LP implantation in patients with relevant bradycardias after TAVR, compared to other indications. Methods: Consecutive patients were retrospectively enrolled. Demographics, background heart diseases, interventional parameters, and follow-up data were collected. Results: A total of 257 consecutive patients who underwent LP implantation were included. In 26 patients, the device was implanted due to bradycardias after TAVR (TAVR group), whereas the remaining 231 patients were in the population without previous TAVR (non-TAVR group). The mean implantation duration (56 ± 22 minutes in the TAVR group vs 48 ± 20 minutes in the non-TAVR group; P = not significant [NS]) and the implantation success rate (100% in the TAVR group vs 98.7% in the non-TAVR group; P = NS) were similar in the 2 cohorts. No significant differences occurred in pacing parameters (sensing, impedance, and threshold, respectively) between the 2 groups, either at implantation or during follow-up. A total of 8 major periprocedural complications (3.1% of patients in total; 3.8% in the TAVR group vs 3.0% in the non-TAVR group; P = NS) occurred within 30 days, without significant difference between the 2 groups. Conclusions: LP implantation appears to be safe and effective in patients after TAVR, and therefore, this procedure is a suitable option for this often old and frail population.

Contexte: L'atteinte du système de conduction cardiaque est une complication courante du remplacement valvulaire aortique par cathéter (RVAC), une intervention habituellement pratiquée chez les patients âgés. Un stimulateur cardiaque sans sonde peut être une option convenable pour cette population fragile, mais les données scientifiques actuelles concernant l'efficacité et l'innocuité de la stimulation sans sonde après un RVAC sont fragmentaires. Cette analyse visait à évaluer l'efficacité et l'innocuité de l'implantation d'un stimulateur cardiaque sans sonde chez des patients atteints de bradycardies pertinentes après un RVAC, comparativement à d'autres indications. Méthodologie: Des patients consécutifs ont été recrutés de manière rétrospective. Les données démographiques, les maladies cardiaques sous-jacentes, les paramètres interventionnels et les données de suivi ont été colligés. Résultats: Un total de 257 patients consécutifs qui se sont fait implanter un stimulateur cardiaque sans sonde ont été inclus. Chez 26 patients, le dispositif a été implanté en raison d'une bradycardie après un RVAC (groupe RVAC), alors que les 231 autres patients formaient la population sans RVAC antérieur (groupe sans RVAC). La durée moyenne de l'intervention d'implantation (56 ± 22 minutes dans le groupe RVAC vs 48 ± 20 minutes dans le groupe sans RVAC; p = non significatif [NS]) et le taux de réussite de l'implantation (100 % dans le groupe RVAC vs 98,7 % dans le groupe sans RVAC; p = NS) étaient similaires dans les deux cohortes. Aucune différence significative n'a été observée dans les paramètres de stimulation (sensibilité, impédance et seuil, respectivement) entre les 2 groupes, que ce soit au moment de l'implantation ou pendant le suivi. Un total de 8 complications périopératoires majeures (3,1 % de l'ensemble des patients; 3,8 % dans le groupe RVAC vs 3,0 % dans le groupe sans RVAC; p = NS) sont survenues dans les 30 jours, sans différence notable entre les 2 groupes. Conclusions: L'implantation d'un stimulateur cardiaque sans sonde semble sûre et efficace après un RVAC; par conséquent, cette intervention représente une option convenable pour cette population souvent âgée et fragile.

Characterization of spatial integrity with active and passive implants in a low-field magnetic resonance linear accelerator scanner.

Background and Purpose: Standard imaging protocols can guarantee the spatial integrity of magnetic resonance (MR) images utilized in radiotherapy. However, the presence of metallic implants can significantly compromise this integrity. Our proposed method aims at characterizing the geometric distortions induced by both passive and active implants commonly encountered in planning images obtained from a low-field 0.35 T MR-linear accelerator (LINAC). Materials and Methods: We designed a spatial integrity phantom defining 1276 control points and covering a field of view of 20x20x20 cm3. This phantom was scanned in a water tank with and without different implants used in hip and shoulder arthroplasty procedures as well as with active cardiac stimulators. The images were acquired with the clinical planning sequence (balanced steady-state free-precession, resolution 1.5x1.5x1.5 mm3). Spatial integrity was assessed by the Euclidian distance between the control point detected on the image and their theoretical locations. A first plane free of artefact (FPFA) was defined to evaluate the spatial integrity beyond the larger banding artefact. Results: In the region extending up to 20 mm from the largest banding artefacts, the tested passive and active implants could cause distortions up to 2 mm and 3 mm, respectively. Beyond this region the spatial integrity was recovered and the image could be considered as unaffected by the implants. Conclusions: We characterized the impact of common implants on a low field MR-LINAC planning sequence. These measurements could support the creation of extra margin while contouring organs at risk and target volumes in the vicinity of implants.

Electrocardiographic predictors of atrial mechanical sensing in leadless pacemakers.

BACKGROUND: Leadless pacemakers (LPs) capable of VDD pacing allow for atrioventricular synchrony through mechanical sensing of atrial contraction. However, mechanical sensing is less reliable and less predictable than electrical sensing. OBJECTIVE: The purpose of this study was to evaluate P-wave amplitude during sinus rhythm from preoperative 12-lead electrocardiograms (ECGs) as a predictor for atrial mechanical sensing in patients undergoing VDD LP implantation. METHODS: Consecutive patients undergoing VDD LP implantation were included in this 2-center prospective cohort study. ECG parameters were evaluated separately and in combination for association with the signal amplitude of atrial mechanical contraction (A4). RESULTS: Eighty patients (median age 82 years; female 55%; mean body mass index [BMI] 25.8 kg/m2) were included in the study and 61 patients in the A4 signal analysis (19 patients in VVI mode during follow-up). Absolute (aVL, aVF, V1, V2) and BMI-adjusted (I, II, aVL, aVF, aVR, V1, V2) P-wave amplitudes from baseline ECGs demonstrated a statistically significant positive correlation with A4 signal amplitude (all P <.05). A combined P-wave signal amplitude of at least 0.2 mV in V1 and aVL was predictive, with specificity of 83% (95% confidence interval 67%-100%) for A4 signal ≥1 m/s2. We found a significant correlation of A4 signal amplitude and overall atrioventricular synchrony (P = .013). CONCLUSION: P-wave amplitudes in ECG leads aVL and V1 can predict A4 signal amplitude in patients with VDD LP and therefore the probability of successful AV synchronous pacing.

Challenges and pitfalls during CRT implantation in patients with persistent left superior vena cava.

BACKGROUND: Persistent left superior vena cava (PLSVC) is a rare venous anomaly, affecting 0.3-0.5% of the general population. Cardiac resynchronization therapy (CRT) implantation in patients with PLSVC is challenging due to a complex anatomy. Moreover, data on CRT implantation in this patient population is scarce. Our aim was to report a series of patients with PLSVC and CRT implantation focusing on challenges and pitfalls. METHODS: Electronic medical databases on patients with CRT implantation at the University Heart Centers in Zurich, Switzerland, and Lübeck, Germany, were screened for individuals with a PLSVC. Clinical and demographic characteristics as well as procedural data were reported in all patients. RESULTS: This study presents six cases with a median age of 66 years. CRT implantation was successful in five patients, leading to a reduced QRS duration and improved left ventricular ejection fraction. Atrial fibrillation, ischemic cardiomyopathy, valvular heart disease, and dilated cardiomyopathy were observed in this group as underlying conditions. Specialized tools, such as active fixation left ventricular leads, were utilized. One patient experienced major complications. CONCLUSIONS: This case series shows that although challenging, conventional endovascular CRT implantation is feasible in PLSVC patients. Specialized tools for visualization and fixation may help. Our experiences highlight the importance of preprocedural evaluation of the anatomy and precise intervention planning.

Catheter Ablation for Ventricular Tachycardia in Patients With Desmoplakin Cardiomyopathy.

BACKGROUND: Desmoplakin (DSP) pathogenic/likely pathogenic (P/LP) variants are associated with malignant phenotypes of arrhythmogenic cardiomyopathy (DSP-ACM). Reports of outcomes after ventricular tachycardia (VT) ablation in DSP-ACM are scarce. OBJECTIVES: In this study, the authors sought to report on long-term outcomes of VT ablation in DSP-ACM. METHODS: Patients with P/LP DSP variants at 9 institutions undergoing VT ablation were included. Demographic, clinical, and instrumental data as well as all ventricular arrhythmia (VA) events were collected. Sustained VAs after the index procedure were the primary outcome. A per-patient before and after ablation comparison of rates of VA episodes per year was performed as well. RESULTS: Twenty-four DSP-ACM patients (39.3 ± 12.1 years of age, 62.5% male, median 6,116 [Q1-Q3: 3,362-7,760] premature ventricular complexes [PVCs] per 24 hours, median 4 [Q1-Q3: 2-11] previous VA episodes per patient at ablation) were included. Index procedure was most commonly endocardial/epicardial (19/24) The endocardium of the right ventricle (RV), the left ventricle (LV), or both ventricles were mapped in 8 (33.3%), 9 (37.5%), and 7 (29.2%) cases, respectively. Low voltage potentials were found in 10 of 15 patients in the RV and 11 of 16 in the LV. Endocardial ablation was performed in 18 patients (75.0%). Epicardial mapping in 19 patients (79.2%) identified low voltage potentials in 17, and 16 received epicardial ablation. Over the following 2.9 years (Q1-Q3: 1.8-5.5 years), 13 patients (54.2%) experienced VA recurrences. A significant reduction in per-patient event/year before and after ablation was observed (1.4 [Q1-Q3: 0.5-2.4] to 0.1 [Q1-Q3: 0.0-0.4]; P = 0.009). Two patients needed heart transplantation, and 4 died (3 of heart failure and 1 noncardiac death). CONCLUSIONS: VT ablation in DSP-ACM is effective in reducing the VA burden of the disease, but recurrences are common. Most VT circuits are epicardial, with both LV and RV low voltage abnormalities. Heart failure complicates clinical course and is an important cause of mortality.