High Risk Of Ventricular Arrhythmias Research Articles

Abstract 4119187: Association of CMR derived Global Longitudinal Strain with adverse Outcomes in Arrhythmogenic Cardiomyopathy.

Background: Arrhythmogenic cardiomyopathy (ACM) is associated with high risk of ventricular arrhythmias (VA) and heart failure (HF). Different predictive models and diagnostic criteria include parameters related to myocardial structural abnormalities and right ventricular (RV) ejection fraction (EF). Nevertheless, the value of global longitudinal strain (GLS) ascertained from cardiac magnetic resonance (CMR) for risk-stratification in the context of ACM is unknown. Aim: We aim to study the association of low CMR-derived GLS with adverse outcomes in ACM patients. Methods: This was a retrospective cohort study of ACM patients seen at a single quaternary center. ACM diagnosis followed the modified 2010 ARVC modified task force criteria. Primary outcome was a composite of life-threatening VAs, heart transplant or HF hospitalization during follow up. We excluded patients who suffered events prior to diagnosis, and those with missing or inadequate CMR protocol. Imaging parameters were acquired by CMR including EF, GLS, and late gadolinium enhancement (LGE). Results: A total of 82 patients with suspected ACM were included, with a median age of 40 years, and 43 (52.4%) were females. Most common reason of initial visit was family history of genetic cardiomyopathy in 46 (56%), while 16 (20%) patients visited our clinic due to history of syncope. Out of 60 patients who had genetic testing, 21 (35%) had mutations of DSP gene. Left ventricular involvement (non-ischemic LV-LGE by CMR) was present in 42 (56.8%) out of 74 patients who had CMR with gadolinium. Median LVEF was 62% (56, 66), and RVEF of 53% (48, 59), both by CMR. Median LVGLS was -17.01% (-14.71, -18.43), while median RVGLS was -20.5% (-18.3, -24.4). A total of 15 (18%) patients suffered the composite endpoint during an average follow up period of 8 years. Patients who suffered the composite endpoint had significantly lower mean LVGLS (-15.04% vs -16.70%, p= 0.048), and lower average RVGLS (-18.45% vs -21.33%, p=0.035) compared to patients free from the adverse outcome. Meanwhile there was no significant difference in LVEF (60.13% vs 61.18%, p=0.67), nor in RVEF (49.13% vs 54.01%, p=0.065) between the two groups. Conclusion: Lower GLS was significantly associated with VAs and HF hospitalizations in our patient population. CMR derived GLS can be used as an important prognostic parameter of adverse outcomes in patients with suspected ACM. Especially in those with LV involvement and high genetic predisposition as our cohort.

ATrial arrhythmias in inhEriTed aRrhythmIa Syndromes: results from the TETRIS study.

Little is known about the distribution and clinical course of patients with inherited arrhythmia syndrome (IAS) and concomitant atrial arrhythmias (AAs). 1) to characterize the distribution of AAs in patients with IAS and 2) evaluate the long-term clinical course of these patients. An international multicenter study was performed and involved 28 centers in 16 countries. Inclusion criteria were: 1) IAS and 2) ECG documentation of AAs. The primary endpoint was a composite of sudden cardiac death, sustained VAs or appropriate ICD interventions. Strokes, inappropriate ICD shocks due to AAs, and the occurrence of sinus node dysfunction were assessed. A total of 522 patients with IAS and AAs were included. Most patients were diagnosed with Brugada syndrome (n=355, 68%) and long-QT syndrome (n=93, 18%). The remaining patients (n=71, 14%) presented with short-QT syndrome, early repolarization syndrome (ERS), catecholaminergic polymorphic ventricular tachycardia (CPVT), progressive cardiac conduction diseases, or idiopathic ventricular fibrillation. Atrial fibrillation (AF) was the most prevalent AA (82%), followed by atrial flutter (9%) and atrial tachycardia (9%). AA was the first clinical manifestation of IAS in 52% of patients. More than one type of AAs was documented in 23% of patients. Nine patients (3%) experienced VA before the diagnosis of IAS, due the use of anti-arrhythmic medications taken for the AA. The incidence of the primary endpoint was 1.4% per year, with a twofold increase observed in patients who experienced their first AA before the age of 20 (OR 2.2, p=0.043). This was consistent across the different forms of IAS. Inappropriate ICD shock due to AAs were reported in 2.8% of patients, strokes in 4.4% and sinus node dysfunction in 9.6%. Among patients with IAS and AAs, AA is the first clinical manifestation in about half of the cases, with more than one form of AAs present in one-fourth of the patients. The occurrence of AA earlier in life may be associated with a higher risk of ventricular arrhythmias. The occurrence of stroke and sinus node dysfunction is not-infrequently in this cohort.

Low levels of apolipoprotein M are associated with increased risk of ventricular arrhythmias

Abstract Background Ventricular arrhythmia (VA) is a frequent cause of sudden cardiac death (SCD). Treatment to prevent SCD includes device therapy with implantable cardioverter defibrillator (ICD). Although the electrophysiology underlying VA have been described, the molecular understanding of VA risk remains unclear. Purpose To identify proteins that are associated with higher and lower risk of VA. Methods SMASH 1 Study was a prospective observational study of 490 patients treated with ICD. The plasma proteome was analyzed with the Olink Explore 384 Cardiometabolic platform at study inclusion, and patients were followed for mean 3.1± 0.7 years. VA events were defined as adjudicated ventricular fibrillation or sustained ventricular tachycardia registered from ICD recordings and clinical events were recorded from electronic health records. Protein concentrations were quantified relatively as normalized protein expression on a log2-transformed concentrations where a large number represents higher protein level in the sample. Results The mean age was 66±12 years, 83% were male and 51% had a primary prevention ICD-indication. Episode(s) of VA occurred in 137 patients (28%) during follow-up. In total, 353 distinct proteins were successfully analyzed in all patients. Among these, high B-type natriuretic peptide (BNP) and N-terminal pro-BNP (NT-proBNP) levels were associated with a higher risk of VA, while Apolipoprotein M (APOM) was the only protein significantly associated with a lower risk of VA after multiple testing using Benjamini-Hochberg correction (Figure, Panel A). After adjusting for age, sex, body mass index, coronary artery disease, heart failure, renal function, left ventricular ejection fraction and antiarrhythmic medication, only low APOM levels remained significantly associated with VA: HR 0.51 (95%CI 0.32-0.79] per log unit increase, p=0.003. Patients in the lowest quartile of APOM had a particularly high risk of incident VA: HR 2.26 (95%CI 1.60-3.19), p=3.61x10-6, compared to quartile 2-4 (Figure, Panel B). High APOM levels were also associated with a lower risk of HF hospitalizations (HR 0.25 [95%CI 0.16-0.40], p<0.001) and all-cause mortality (HR 0.36 [95%CI 0.22-0.60], p<0.001), and these associations remained significant in adjusted models. Conclusions Low levels of APOM are associated with a greater risk of incident VA, independently of established risk factors. Low APOM also predicted risk of HF hospitalizations and mortality in our cohort, which suggest protective cardiovascular effects of APOM. Figure: Association of individual proteomic measures with risk of ventricular arrhythmias (VA).A:Volcano plots of the associations of individual plasma proteins with incident VA. The dotted line represents the significance level at false discovery rate <0.05 and the red dots are significant proteins after multiple testing using Benjamini-Hochberg correction.B: Risk of VA by quartile of Apolipoprotein M.

Smaller intrinsic QRS area and smaller reduction of QRS area during cardiac resynchronisation therapy are associated with higher risk of ventricular arrhythmias and appropriate ICD therapy

Abstract Background Cardiac resynchronisation therapy (CRT) patients are at high risk for ventricular arrhythmias (VAs), and little is known about which characteristics are associated with an increased risk for arrhythmic events. Purpose To investigate the association between QRS area parameters and the risk for VAs in patients with heart failure undergoing primary preventive CRT with defibrillator (CRT-D) implantation. Methods All patients receiving CRT-D between 2015 and 2020 at a large-volume tertiary care center were retrospectively evaluated. Digital 12-lead electrocardiograms (ECGs) were collected before and after CRT implantation. Patients were included if they had native LBBB and were implanted with a primary preventive CRT-D. Kors’ regression transformation was used to derive vectorcardiographic QRS area from the 12-lead ECGs. QRS area parameters were analysed in relation to a primary endpoint of first appropriate ICD therapy, i.e., ATP or shock therapy. Results 177 patients with LBBB (68.9 years [60.7–73.8]; 21.5% female; 52.9% New York Heart Association (NYHA) class III-IV; LVEF 25.9±6.3%) were followed over a median follow-up time of 2.5 years [1.6–3.0] after CRT-D implantation. 27 patients reached the primary endpoint. The median pre-CRT QRS area was 134.5 μVs [102.3–163.8]. Multivariable Cox regression identified a small pre-CRT QRS area (HR, per 10 μVs decrease, 1.30; [1.12–1.51]; p=<.001) and a small post-CRT reduction in QRS area (HR, per 10 μVs decrease, 1.30; [1.13–1.49]; p=<.001) as independent predictors of an increased risk of appropriate ICD therapy. In analyses with a scoring variable combining pre-CRT QRS area and QRS area reduction both above or below median, the combination of a small pre-CRT QRS area and a small QRS area reduction was strongly associated with an increased risk of reaching the endpoint (HR, per point increase, 2.47; [1.2–4.9]; p=0.01). Conclusion A small intrinsic QRS area, by itself or in combination with a small reduction of post-CRT QRS area, was strongly associated with a higher risk of ventricular arrhythmias in this cohort of CRT-D treated patients. In conjunction with other parameters, further risk stratification for arrhythmic events could be achieved by assessing QRS area data pre- and post-CRT.Figure 1.K-M pre-CRT QRS area quartilesFigure 2.K-M QRS area score

Right Bundle Branch Block Predicts Appropriate Implantable Cardioverter Defibrillator Therapies in Patients with Non-Ischemic Dilated Cardiomyopathy and a Prophylactic Implantable Cardioverter Defibrillator.

Background: The benefit of prophylactic implantable cardioverter defibrillators (ICDs) in patients with severe systolic dysfunction of non-ischemic origin is still unclear, and the identification of patients at risk for sudden cardiac death remains a major challenge. Aims/Methods: We retrospectively reviewed all consecutive patients with non-ischemic dilated cardiomyopathy (NICM) who underwent prophylactic ICD implantation between 2008 and 2020 in two tertiary centers. Our main goal was to identify the predictors of appropriate ICD therapies (anti-tachycardia pacing [ATP] and/or shocks) in this cohort of patients. Results: A total of 224 patients were included. After a median follow-up of 51 months, 61 patients (27.2%) required appropriate ICD therapies. Patients with appropriate ICD therapies were more frequently men (87% vs. 69%, p = 0.006), of younger age (59 years, (53-65) vs. 64 years, (57-70); p = 0.02), showed more right bundle branch blocks (RBBBs) (15% vs. 4%, p = 0.007) and less left bundle branch blocks (LBBBs) (26% vs. 47%, p = 0.005) in the ECG, and had higher left ventricular end-diastolic (100 mL/m2, (90-117) vs. 86, (71-110); p = 0.011) and systolic volumes (72 mL/m2, (59-87) vs. 61, (47-81), p = 0.05). In a multivariate competing-risks regression analysis, RBBB (HR 2.26, CI 95% 1.02-4.98, p = 0.043) was identified as an independent predictor of appropriate ICD therapies. Conclusion: RBBBs may help to identify patients with NICM at high risk of ventricular arrhythmias and requiring ICD intervention.

ICD in Cardiac Sarcoidosis: Variables Associated with Appropriate Therapy, Inappropriate Therapy, and Device Complications

Introduction: Those with cardiac sarcoidosis (CS) are at risk of sudden cardiac death (SCD), which may be prevented using an implantable cardioverter–defibrillator (ICD). There are limited data available that follow the post-procedural outcomes of patients with cardiac sarcoidosis (CS) who have had an ICD implanted. Areas Covered: This review highlights studies that focused on both appropriate and inappropriate therapies in those with an ICD, as well as device complications in this group. There were several variables, including age, sex, ventricular characteristics, and findings on cardiac imaging that were investigated and discussed as influencing factors in predicting appropriate and inappropriate therapies. Conclusions: Adverse events in those with an ICD and CS have been minimally reported in the literature. Individuals diagnosed with CS are at high risk of ventricular arrhythmia, with comparable rates of appropriate therapy but with a higher incidence of side effects and inappropriate therapy. The younger average age of CS patients in comparison to other ICD cohorts warrants the need for further, large-scale, prospective trials with periodic interim follow-ups focused on those with this condition.

Cardiac Magnetic Resonance as Risk Stratification Tool in Non-Ischemic Dilated Cardiomyopathy Referred for Implantable Cardioverter Defibrillator Therapy-State of Art and Perspectives.

Non-ischemic dilated cardiomyopathy (DCM) is a disease characterized by left ventricular dilation and systolic dysfunction. Patients with DCM are at higher risk for ventricular arrhythmias and sudden cardiac death (SCD). According to current international guidelines, left ventricular ejection fraction (LVEF) ≤ 35% represents the main indication for prophylactic implantable cardioverter defibrillator (ICD) implantation in patients with DCM. However, LVEF lacks sensitivity and specificity as a risk marker for SCD. It has been seen that the majority of patients with DCM do not actually benefit from the ICD implantation and, on the contrary, that many patients at risk of SCD are not identified as they have preserved or mildly depressed LVEF. Therefore, the use of LVEF as unique decision parameter does not maximize the benefit of ICD therapy. Multiple risk factors used in combination could likely predict SCD risk better than any single risk parameter. Several predictors have been proposed including genetic variants, electric indexes, and volumetric parameters of LV. Cardiac magnetic resonance (CMR) can improve risk stratification thanks to tissue characterization sequences such as LGE sequence, parametric mapping, and feature tracking. This review evaluates the role of CMR as a risk stratification tool in DCM patients referred for ICD.

Imaging for the assessment of the arrhythmogenic potential of mitral valve prolapse.

Mitral valve prolapse (MVP) is the most common valve disease in the western world and recently emerged as a possible substrate for sudden cardiac death (SCD). It is estimated an annual risk of sudden cardiac death of 0.2 to 1.9% mostly caused by complex ventricular arrhythmias (VA). Several mechanisms have been recognized as potentially responsible for arrhythmia onset in MVP, resulting from the combination of morpho-functional abnormality of the mitral valve, structural substrates (regional myocardial hypertrophy, fibrosis, Purkinje fibers activity, inflammation), and mechanical stretch. Echocardiography plays a central role in MVP diagnosis and assessment of severity of regurgitation. Several abnormalities detectable by echocardiography can be prognostic for the occurrence of VA, from morphological alteration including leaflet redundancy and thickness, mitral annular dilatation, and mitral annulus disjunction (MAD), to motion abnormalities detectable with "Pickelhaube" sign. Additionally, speckle-tracking echocardiography may identify MVP patients at higher risk for VA by detection of increased mechanical dispersion. On the other hand, cardiac magnetic resonance (CMR) has the capability to provide a comprehensive risk stratification combining the identification of morphological and motion alteration with the detection of myocardial replacement and interstitial fibrosis, making CMR an ideal method for arrhythmia risk stratification in patients with MVP. Finally, recent studies have suggested a potential role in risk stratification of new techniques such as hybrid PET-MR and late contrast enhancement CT. The purpose of this review is to provide an overview of the mitral valve prolapse syndrome with a focus on the role of imaging in arrhythmic risk stratification. CLINICAL RELEVANCE STATEMENT: Mitral valve prolapse is the most frequent valve condition potentially associated with arrhythmias. Imaging has a central role in the identification of anatomical, functional, mechanical, and structural alterations potentially associated with a higher risk of developing complex ventricular arrhythmia and sudden cardiac death. KEY POINTS: • Mitral valve prolapse is a common valve disease potentially associated with complex ventricular arrhythmia and sudden cardiac death. • The mechanism of arrhythmogenesis in mitral valve prolapse is complex and multifactorial, due to the interplay among multiple conditions including valve morphological alteration, mechanical stretch, myocardial structure remodeling with fibrosis, and inflammation. • Cardiac imaging, especially echocardiography and cardiac magnetic resonance, is crucial in the identification of several features associated with the potential risk of serious cardiac events. In particular, cardiac magnetic resonance has the advantage of being able to detect myocardial fibrosis which is currently the strongest prognosticator.

Chronic safety and performance of the extravascular ICD: results from the global EV ICD Pivotal study

Abstract Background Implantable cardioverter defibrillators (ICDs) prevent sudden cardiac death in patients at high risk for ventricular arrhythmias, but conventional systems carry a risk of transvenous (TV) lead-related complications. The novel extravascular ICD (EV ICD) may reduce some of these complications, while offering anti-tachycardia pacing (ATP), pause prevention pacing, and a device of similar size and projected battery longevity as a TV ICD, by placing a lead substernally. The EV ICD Pivotal study demonstrated EV ICD safety and performance for termination of ventricular arrythmias at 6 months. Longer-term performance is unknown. Purpose To report the chronic safety and performance of the EV ICD system. Methods The extravascular implantable cardioverter defibrillator (EV ICD) Pivotal study was a prospective, international, single-arm, premarket clinical study. Patients with a class I or IIa indication for a single-chamber ICD per ESC or ACC/AHA/HRS guidelines were enrolled. Freedom from major system- and/or procedure-related complications at 18 mo was evaluated, as well as conversion of arrhythmias by anti-tachycardia pacing (ATP) or shock through all available follow up. Rates of ATP success were evaluated using the generalized estimating equation (GEE) and simple proportions. Results Implantation was attempted in 316 patients: 74.7% male, age 53.8±13.1 years, 82% primary prevention, left ventricular ejection fraction of 38.9%±15.4%, and New York Heart Association Class I (23.4%) or II/III (65.5%). Of 299 implanted patients (average follow up 16.2±7.2 mo), 19 experienced 80 spontaneous, appropriately treated arrhythmic episodes: 37 treated by ATP, 15 by ATP and shock, and 28 by shock alone with a Kaplan-Meier (KM) estimated 6.8% of patients experiencing appropriate therapy by 18 mo (Figure). Of discrete episodes treated with shock, 21/21 (100%) were successfully terminated. ATP was delivered in 12 patients, successfully treating 35/52 episodes (67.3%; GEE adjusted 59.0%). Inappropriate shocks occurred in 35 patients through all follow up, with a rate of 10.2% at 1 year. The KM estimate of freedom from major EV ICD system-or procedure-related complications rate through 18 mo was 91.9% (95% CI: 88.2% to 94.4%). The most common event was lead dislodgment (10 events in 9 patients) identified 0 to 120 days post-implant, predominantly due to anchoring technique. Conclusion The safety and effectiveness of a novel EV ICD system with a substernal lead extends through chronic follow up. Shocks were avoided in nearly half of all spontaneous episodes because of the availability of ATP.Figure

Arrhythmic form of mitral valve prolapse: presentation, risk stratification and management

Abstract Background Mitral valve prolapse (MVP) is a common finding that has been considered as benign condition for a long time. However, some anatomic forms have been recently recognized to be associated with life-threatening ventricular arrhythmia and sudden cardiac death (SCD), recently known as arrhythmic MVP (AMVP). Objectives This study is aiming to clinically characterize and risk stratify patients with malignant phenotype of MVP of high risk for ventricular arrhythmia which may lead to SCD. We aim to explore characteristics and assess potential markers for MVP induced ventricular arrhythmia that might need monitoring and follow up with medical or invasive treatment as implantable cardioverter-defibrillator, catheter ablation or even surgical repair. Methods A prospective cohort study of 45 (age 35±8, 29 females), consecutive patients with MVP and/or mitral annular disjunction (MAD) and comprehensive clinical arrhythmia on resting electrocardiography (ECG) or 48-hours Holter monitoring , Doppler echocardiography and contrast based cardiac magnetic resonance (CMR) characterization were identified. Patients were followed-up for a period of maximum one year to identify any further management needed. Results Frequent ventricular arrhythmia was evidently seen associated to MVP (69% with at least ventricular ectopy ≥5%), as well as complex ventricular arrhythmia (31% with sustained or non-sustained ventricular tachycardia ) P<0.001. AMVP was strongly associated with premature ventricular contractions (PVCs) having Right bundle branch block (RBBB) morphology on ECG and late gadolinium enhancement (LGE) on CMR (all p<0.05). Furthermore, it was shown to be associated with bileaflet prolapse and higher left ventricular volumes, however not statistically significant. On Follow-up, Out of 36 patients with ventricular arrhythmia, 64% were controlled on medical anti-arrhythmic and some others were referred either for ablation after worsening of symptoms despite of medical treatment (27.8%), implantable cardioverter-defibrillator device for secondary VT prophylaxes (5.6%) or surgery (2.8%) due to progression in mitral regurgitation severity and deterioration of symptoms. Conclusion In this small cohort study, characteristic form of MVP was found to be associated with ventricular arrhythmia more common in the form of frequent PVCs and less common in the complex form. Although majority of patients were controlled on medical treatment, few patients required further invasive management despite of medical treatment . Thus, arrhythmia associated with a special form of MVP could be life threatening and needs close monitoring, long follow-up and proper management approach to prevent SCD. Large prospective studies with comprehensive approach and long term follow up is pivotal. CMR T1 mapping and electro anatomical CARTO mapping could help in better detection and proper defining of arrhythmia substrate in future studies.AMVP illustration

Abstract 18780: Prognostic Value of Cardiovascular Magnetic Resonance Feature Tracking Strain in Patients With Suspected Cardiac Sarcoidosis

Background: Cardiac sarcoidosis (CS) is associated with a high risk of ventricular arrhythmia (VA) and heart failure (HF). Cardiovascular magnetic resonance imaging (CMR) is often used for the diagnosis and prognostication of suspected CS. Small studies have shown promise for ventricular strain as a marker of adverse outcomes in suspected CS. Aim: We aimed to investigate the prognostic value of CMR global longitudinal strain (GLS) in patients with suspected CS. Methods: Using a retrospective cohort design, we studied consecutive patients with histologically proven sarcoidosis who underwent CMR for the evaluation of suspected CS from 2004 to 2021. Feature-tracking GLS was assessed for the left and right ventricles (LV and RV). Kaplan-Meier and Cox proportional hazards regression analyses were used to determine the association between GLS, and VA and HF composite endpoints. Results: Among 557 patients (mean age 54 years, 47% women), the median LVGLS was -14.8% and the median RVGLS was -16.2%. Over a median follow-up of 5.8 years, 39 patients reached the VA endpoint, and 63 reached the HF endpoint. On Kaplan-Meier analyses, patients with either LVGLS or RVGLS worse than the median had a higher estimated cumulative incidence of both endpoints compared with patients with GLS better than the median (log-rank P<0.001 for all comparisons). On multivariable regression analyses, LVGLS was not associated with the VA endpoint [hazard ratio (HR) 0.93 per 1% worsening; 95% confidence interval (CI) 0.83-1.05; P=0.25], but RVGLS was independently associated (HR 1.13 per 1% worsening; 95% CI 1.02-1.25; P=0.015) in a model that included the extent of late gadolinium enhancement (LGE) and the presence of the high-risk CMR phenotype. Neither LVGLS (HR 1.08, 95% CI 0.98-1.12; P=0.11) nor RVGLS (HR 1.04, 95% CI 0.96-1.13; P=0.31) were independently associated with the HF endpoint in a model that included age, pulmonary hypertension, and the high-risk CMR phenotype. Conclusions: In patients with suspected CS, RVGLS was independently associated with long-term VA but not HF outcomes, while LVGLS was not independently associated with either. Research is warranted into the role of CMR RVGLS to aid clinical decision-making regarding implantable cardioverter-defibrillators.

Systolic blood pressure ≤110 mm Hg is associated with severe coronary microvascular ischemia and higher risk for ventricular arrhythmias in hypertrophic cardiomyopathy

Systolic blood pressure ≤110 mm Hg is associated with severe coronary microvascular ischemia and higher risk for ventricular arrhythmias in hypertrophic cardiomyopathy

Association of epicardial and intramyocardial fat with ventricular arrhythmias

Among patients with ischemic cardiomyopathy (ICM) and nonischemic cardiomyopathy (NICM), myocardial fibrosis is associated with an increased risk for ventricular arrhythmia (VA). Growing evidence suggests that myocardial fat contributes to ventricular arrhythmogenesis. However, little is known about the volume and distribution of epicardial adipose tissue and intramyocardial fat and their relationship with VAs. The purpose of this study was to assess the association of contrast-enhanced computed tomography (CE-CT)-derived left ventricular (LV) tissue heterogeneity, epicardial adipose tissue volume, and intramyocardial fat volume with the risk of VA in ICM and NICM patients. Patients enrolled in the PROSE-ICD registry who underwent CE-CT were included. Intramyocardial fat volume (voxels between -180 and -5 Hounsfield units [HU]), epicardial adipose tissue volume (between -200 and -50 HU), and LV tissue heterogeneity were calculated. The primary endpoint was appropriate ICD shocks or sudden arrhythmic death. Among 98 patients (47 ICM, 51 NICM), LV tissue heterogeneity was associated with VA (odds ratio [OR] 1.10; P = .01), particularly in the ICM cohort. In the NICM subgroup, epicardial adipose tissue and intramyocardial fat volume were associated with VA (OR 1.11, P = .01; and OR = 1.21, P = .01, respectively) but not in the ICM patients (OR 0.92, P =.22; and OR = 0.96, P =.19, respectively). In ICM patients, increased fat distribution heterogeneity is associated with VA. In NICM patients, an increased volume of intramyocardial fat and epicardial adipose tissue is associated with a higher risk for VA. Our findings suggest that fat's contribution to VAs depends on the underlying substrate.

Effect of myocardial scar size on the risk of ventricular arrhythmias in patients with chronic total coronary occlusion

BackgroundThe presence of an untreated chronic total coronary occlusion (CTO) is associated with a higher risk of ventricular arrhythmias (VAs). This increased risk may be modulated by the presence of an existing scar. ObjectivesTo evaluate whether scar size is associated with VA in patients with an implantable cardioverter-defibrillator (ICD) and a CTO. MethodsIn this retrospective study we included patients with a CTO that received an ICD between 2005 and 2015. Scar size was estimated using the Selvester QRS score on a baseline 12‑lead ECG. The primary endpoint was any appropriate ICD therapy. ResultsOur study population comprised 148 CTO patients with a median scar size at baseline of 18% (IQR, 9–27%). Patients with a scar size ≥18% more often had a CTO located in the left anterior descending artery and a higher proportion of poor left ventricular function (<35%) and infarct-related CTO compared to patients with a smaller scar size (<18%). During a median follow-up of 35 months (interquartile range [IQR], 8–60 months), 42 patients (28%) received appropriate ICD therapy. The cumulative 5-year event rate was higher in the patients with a large scar in comparison to those with a smaller or no scar (36% versus 19%, P = 0.04). Multivariable Cox regression analysis demonstrated that large scar and diabetes mellitus were independent factors associated with appropriate ICD therapy. ConclusionIn ICD recipients with an untreated CTO, a larger scar is an independent factor associated with an increased risk of VA.

Effect of infarct size on the risk of ventricular arrhythmias in patients with chronic total coronary occlusion

Abstract Funding Acknowledgements Type of funding sources: None. Background The presence of an untreated chronic total coronary occlusion (CTO) is associated with a higher risk of ventricular arrhythmias (VAs). This increased risk may be modulated by the presence of existing scar. We hypothesize that a larger scar size is associated with a higher risk of VA. Objectives To evaluate whether infarct size is associated with VA in patients with an implantable cardioverter-defibrillator (ICD) and an untreated CTO. Methods In this retrospective study we included patients with an untreated CTO that received an ICD between 2005 and 2014. Infarct size was estimated using the Selvester QRS score on a baseline 12-lead ECG. The primary endpoint was any appropriate ICD therapy. Results Our study population comprised 148 patients (mean age at implantation 64 ± 10 years, 87% men) with an ICD and an untreated CTO. The median infarct size at baseline was 18% (IQR, 9-27%). Patients with a larger scar size (≥18%) more often had a CTO location in the LAD, higher proportion of LVEF &amp;lt;35%, and less hypertension and hypercholesterolemia compared to patients with a smaller infarct size (&amp;lt;18%). During a median follow-up of 35 months (interquartile range [IQR], 8-60 months), 42 patients (28%) received appropriate ICD therapy. The cumulative 5-year event rate was higher in the patients with a large infarct size (≥18%) in comparison to those with a smaller infarct size (&amp;lt;18%) (36% versus 19%, logrank P = 0.038, Figure). Multivariable Cox regression analysis demonstrated that a larger infarct size (≥18%) and a secondary prevention indication were independent factors associated with appropriate ICD therapy. The adjusted hazard ratio of large infarct size (≥18%) for appropriate ICD therapy was 2.34 (95% CI 1.20-4.58, p=0.01). Conclusion In ICD recipients with an untreated CTO, a larger scar size is an independent factor associated with an increased risk of VA.

Association of ivabradin use with ventricular arrhythmias in heart failure patients

Abstract Funding Acknowledgements Type of funding sources: None. Background/Introduction Heart failure patients with reduced left ventricular function are at high risk for ventricular arrhythmias and sudden cardiac death. Ivabradine, a specific inhibitor of the If current in the sinoatrial node, provides heart rate reduction in sinus rhythm and angina control in chronic coronary syndromes. Purpose The effect of ivabradine on ventricular arrhythmias in heart failure patients has not been fully elucidated. In this study, we aimed to investigate the effect of ivabradine use on life-threatening arrhythmias and long-term mortality in heart failure patients. Methods In this retrospective study, 1639 patients with heart failure were included. Patients were divided into two groups as ivabradine users and non-users. Patients presenting with ventricular tachycardia, presence of ventricular extra systole and ventricular tachycardia in 24-hour rhythm monitoring, appropriate ICD shocks and long-term mortality outcomes were evaluated according to ivabradine use. Results After adjustment for clinical variables, admission with ventricular tachycardia had 3.0 higher rates in ivabradine non-users (95% CI: 1.5 – 10.2). According to the adjusted model for all variables, approximately 4.1 times more appropriate ICD shocks were observed in the ivabradine non-users than the users (95% CI: 1.8 – 9.6). Long-term mortality did not differ between these groups after adjustment for all covariates. Conclusion The use of ivabradine reduced the appropriate ICD discharge in heart failure patients with low ejection fraction. Ivabradine has a potential in the treatment of ventricular arrhythmias in heart failure patients.

Patients with Achilles Tendon Rupture Are Prone to Develop Ventricular Arrhythmia.

This study aimed to examine the ventricular repolarization (VR) disturbances of patients operated on for acute spontaneous Achilles tendon ruptures (ATRs), by comparing them with a healthy individual control group. Between June 2014 and July 2020, a total of 29 patients (28 males, 1 female; mean age: 40 ± 9.78 years; range, 21-66 years) who presented to the emergency department within the first three weeks of injury, and were diagnosed with acute spontaneous ATRs and treated with an open Krackow suture technique, were retrospectively analyzed. Fifty-two healthy individuals (47 males, 5 females; mean age: 39 ± 11.45 years; range, 21-66 years) were recruited as a control group from the cardiology outpatient clinic. Clinical data (demographic features and laboratory parameters (serum glucose, creatinine, hemoglobin, white blood cell count, and lipid profile)) and electrocardiograms (ECGs) were collected from medical records. ECGs were evaluated for heart rate and VR parameters of QRS width, QTc interval, cQTd interval, Tp-e interval, and Tp-e/QT ratio. The clinical data and these ECG parameters were compared between groups. There was no statistically significant difference between groups, regarding clinical data (all p < 0.05). Among ECG parameters, heart rate, QRS width, QTc interval, and cQTd interval were similar between groups (all p < 0.05). There were two important statistically significant findings of this research: The mean Tp-e interval was longer (ATR group: 72.4 ± 24.7, control group: 58.8 ± 14.5, p: 0.01), and the Tp-e/QT ratio was higher (ATR group: 0.2 ± 0.1, control group: 0.16 ± 0.4, p: 0.027) in the ATR group. According to the ventricular repolarization disturbances found in this study, patients with ATR may be at a higher risk of ventricular arrhythmia than healthy people. As a result, ATR patients should be assessed for ventricular arrhythmia risk by an expert cardiologist.

LB-456087-2 CHRONIC SAFETY AND PERFORMANCE OF THE EXTRAVASCULAR ICD: RESULTS FROM THE GLOBAL EV ICD PIVOTAL STUDY

ICDs prevent SCD in patients at high risk for ventricular arrhythmias, but conventional systems carry a risk of transvenous (TV) lead-related complications. The novel extravascular ICD (EV ICD) may reduce some of these complications, while offering ATP, pause prevention pacing, and a device of similar size and projected battery longevity as a TV ICD, by placing a lead substernally. The EV ICD Pivotal study demonstrated EV ICD safety and performance for termination of ventricular arrythmias at 6 months. Longer-term performance is unknown.

Impact of fibrosis extend on multiparametric assessment for ventricular arrhythmias risk in non-ischemic dilated cardiomyopathy

The consensus guidelines recommended implantable cardioverter defibrillators (ICD) for sudden cardiac death prevention in patient with non-ischemic dilated cardiomyopathy (DCM) and LVEF < 35%. However, recent data suggest that it will not affect prognosis. Some markers have identified patients with higher risk of ventricular arrhythmias independently of LVEF. Better optimization of risk stratification for sudden cardiac death and specify implantation criteria are necessary. We performed comprehensive cardiac evaluation including imaging to predict ventricular arrhythmias in a population of non-ischemic DCM. We conducted a monocentric retrospective study including 107 patients with non-ischemic DCM and implanted with ICD as primary prevention from 2013 to 2019. Primary outcome is composite of appropriate therapy by ICD for ventricular tachycardia and ventricular fibrillation or sudden cardiac death. All-cause mortality and LVEF progress are secondary outcome. Primary outcome occurred in 21 patients (20%). In univariate analysis, GFR especially when it is < 50 mL.min-1.1.73 m-2(HR 4.62, P = 0.003), right ventricle ejection fraction under 40% (HR 2.48, p 0.04), number of segments with LGE (HR 1.22, P < 0.001) especially when there are 3 or more (HR 5.47, P < 0.001) or subepicardial location (HR 3.33, P = 0.03) are associated with ventricular arrhythmias. In a multiparametric assessment, this study highlights one important parameter associated with ventricular arrhythmias in selected population of non-ischemic DCM and LVEF < 35%: the extend of myocardial fibrosis, especially with 3 or more segments with LGE. It supports the concept of “critical mass” of fibrosis necessary for initiation and maintenance of ventricular arrhythmias. It was demonstrated in ischemic heart disease but a threshold value remains to be determined in non-ischemic DCM. The main result (Fig. 1).

Arrhythmogenic cardiomyopathy as a myogenic disease: highlights from cardiomyocytes derived from human induced pluripotent stem cells.

Arrhythmogenic cardiomyopathy (ACM) is an inherited cardiomyopathy characterized by the replacement of myocardium by fibro-fatty infiltration and cardiomyocyte loss. ACM predisposes to a high risk for ventricular arrhythmias. ACM has initially been defined as a desmosomal disease because most of the known variants causing the disease concern genes encoding desmosomal proteins. Studying this pathology is complex, in particular because human samples are rare and, when available, reflect the most advanced stages of the disease. Usual cellular and animal models cannot reproduce all the hallmarks of human pathology. In the last decade, human-induced pluripotent stem cells (hiPSC) have been proposed as an innovative human cellular model. The differentiation of hiPSCs into cardiomyocytes (hiPSC-CM) is now well-controlled and widely used in many laboratories. This hiPSC-CM model recapitulates critical features of the pathology and enables a cardiomyocyte-centered comprehensive approach to the disease and the screening of anti-arrhythmic drugs (AAD) prescribed sometimes empirically to the patient. In this regard, this model provides unique opportunities to explore and develop new therapeutic approaches. The use of hiPSC-CMs will undoubtedly help the development of precision medicine to better cure patients suffering from ACM. This review aims to summarize the recent advances allowing the use of hiPSCs in the ACM context.