Therapy For Ventricular Arrhythmias Research Articles

Management of Ventricular Arrhythmias in Heart Failure: Can Less Be More?

Ventricular arrhythmias (VAs) affect many patients with heart failure and underlying structural heart disease and are associated with significant morbidity and mortality. Antiarrhythmic drugs are often the initial treatment, but medication alone often fails to sufficiently suppress VAs. While catheter ablation (CA) remains the gold standard for treatment of VAs, CA is an invasive procedure and can be associated with periprocedural complications including acute clinical decompensation. Thus, there is an important need for alternative therapies. Recent advances in risk stratification and the development of new ablation technologies may reduce some of the periprocedural complications and limitations of CA. In addition, less invasive therapies for VAs may provide an alternative treatment strategy for patients in both the acute and chronic setting. For patients acutely admitted with ventricular tachycardia electrical storm (VT-ES) or recurrent VT and cardiogenic shock, risk stratification tools have been developed to identify patients at high risk of acute hemodynamic decompensation during CA. These patients require a multidisciplinary approach and might need mechanical circulatory support (MCS) if CA is selected as the treatment strategy. Alternatively, less invasive therapies targeting the autonomic nervous system may be reasonable. In the chronic setting, developments in medical therapy have reduced the risk of sudden cardiac death in heart failure patients and stereotactic whole-body radiation (SBRT) has evolved as a potential, non-invasive therapy. Further research is needed to personalize VA therapy for individual patients.

Feasibility, safety, and short-term follow-up of defibrillator lead at left bundle branch area pacing location: A pilot study

BackgroundLeft bundle branch area pacing (LBBAP) has been increasingly adopted as an alternative modality to cardiac resynchronization therapy (CRT). The feasibility and safety of using an LBBAP lead to provide sensing of ventricular arrhythmia in patients receiving an implantable cardioverter-defibrillator (ICD) with CRT has been demonstrated recently. ObjectivesThe purpose of our study was to analyze the feasibility, safety, and short-term follow-up of a traditional defibrillator lead at the LBBAP location. MethodsPatients who underwent successful LBBAP defibrillator using DF-1/DF-4 lead and delivery catheter were included in the study. Defibrillation threshold (DFT) testing was performed after implantation to assess the ability of the LBBAP defibrillator lead to sense and provide appropriate therapy for ventricular arrhythmia. ResultsAlthough the ICD lead could be successfully deployed in the left bundle branch area in 7 of 8 patients, it was repositioned to the right ventricular (RV) apex because of atrial oversensing in 1 patient and cheesy septum in another patient. Acute procedural success was 62.5% (5/8 patients). Mean patient age was 62.6 ± 21.6 years. Mean procedural duration was 115.6 ± 38.1 minutes, with LBBAP defibrillator lead fluoroscopy duration of 10.6 ± 3.5 minutes. Mean capture threshold was 0.58 ± 0.23V/0.4 ms, sensed R-wave amplitude 9.6 ± 2.2 mV, pacing impedance 560 ± 145 Ω, and shock impedance 65.4 ± 5.5 Ω. Defibrillation testing was successful in inducing ventricular fibrillation and could be sensed and reverted promptly by the shock delivered through the lead. During mean follow-up of 3.8 ± 2.2 months, pacing parameters remained stable. No episodes of inappropriate arrhythmia detection or therapy delivery occurred during follow-up. ConclusionLBBAP defibrillator is feasible, safe, and effective during short-term follow-up. DFT testing at the time of implantation will help to ensure appropriate sensing and treatment of ventricular arrhythmias.

Predictors of unsuccessful radiofrequency catheter ablation of idiopathic ventricular arrhythmias in children

Ventricular arrhythmias (VAs) in children are generally idiopathic and have a benign course. Catheter ablation (CA) is increasingly becoming a first-line treatment option in children with idiopathic VAs. Acute ablation success reaches 100% procedures and long-term – 87%. Predictors of outcomes of CA in pediatric patients with idiopathic VAs have not been fully investigated.Aim: To identify predictors of long-term unsuccessful outcomes of CA in pediatric idiopathic VAs.Material and Methods. This retrospective study included 164 children aged 7 to 17 years with idiopathic VAs, who underwent CA from 2011 until 2023 in Almazov National Medical Research Centre. Efficiency was assessed in acute period and 6 months after CA.Results. In this study the acute success was 92% and long-term success was 88,4%. In multivariable models, multifocal VAs (odds ratio: 8,814; 95% CI: 1,943–39,981; p = 0,005), effectiveness of antiarrhythmic therapy (odds ratio: 16,522; 95%CI: 1,959–139,374; p = 0,010) and noninducibility of VAs during procedure (odds ratio: 9,369; 95% CI: 1,400–62,684; 0,021), become predictors of long-term unsuccessful outcomes of CA in pediatric idiopathic VAs.Conclusion. In our study there were identified independent predictors of long-term noneffective CA in children with idiopathic VAs, such as multifocal VAs, effectiveness of antiarrhythmic therapy, and noninducibility of VAs CA. In patients with presence of two or more ventricular foci and the effectivness of antiarrhythmic therapy, prolongate drug therapy may be more preferable.

Sex and Gender Differences in Ventricular Arrhythmias

Ventricular arrhythmias, including ventricular tachycardia and VF, commonly occur in patients with underlying cardiomyopathy. Sex differences exist in almost every aspect of ventricular arrhythmia from epidemiology, anatomy, and physiology to management and response to therapy. Some of these may be attributed to variations in etiology, types, and rates of cardiomyopathy as well as biological differences between males and females, but the full explanation for these differences remains incomplete. Additionally, women have been underrepresented in many trials studying therapies for ventricular arrhythmias including ICD placement and ablation; thus, there remains a need for continued research in this population. This review will discuss the differences between the sexes as well as outline opportunities for future research in women with ventricular arrhythmias.

Myocardial deformation as a stratification tool in HCM

Abstract Funding Acknowledgements Type of funding sources: None. Background/Introduction Sudden cardiac death (SCD) is a major issue in hypertrophic cardiomyopathy (HCM) management, and its risk prediction stays challenging for clinicians. Ventricular arrythmias (VAs) have to be treated rapidly, indeed VAs lower prognosis in HCM patients. Current ESC guidelines for cardioverter-defibrillator implantation include left atrial (LA) whereas left ventricle (LV) ejection function (LVEF) is incorporated in AHA latest guidelines. We explore the potential role of LA and LV strain as more sensible parameters in HCM rhythmic prognostication. Purpose To assess LA and LV strain in risk stratification in HCM patients as accurate markers of SCD. Methods Patients with newly diagnosed HCM were enrolled in three French University Hospital (Marseille, Bordeaux and Rennes) between 2007 and 2018. At the inclusion we realized a comprehensive clinical exam, biological analysis, an echocardiography including LA strain in two and four apical-chambers, and a MRI. Composite primary endpoint (PE) analysis was occurrence of rhythmic related adverse cardiac events: ventricular tachycardia (VT), ICD therapy for ventricular arrhythmia, or all-cause death. Occurrence and dates of endpoints were retrieved by patient’s medical records and phone calls to all patients and family members. Results At a mean follow-up of 57 (34–82) months, patients with adverse cardiac events (n = 52) presented with more impaired LA and LV deformation function. After multivariate analysis, we found a significant association between impaired LA strain and our composite primary endpoint P 0,023 HR 0,95. LV strain revealed to be correlated with our PE P 0,012 HR 2,48. Conclusions Myocardial deformation appears to be a relevant marker which could be linked to sudden cardiac death in HCM. These parameters might be relevant in new risk calculators.

Appropriate and inappropriate therapies in remotely monitored patients with cardiac implantable devices long-term experiences of a tertiary centre

Abstract Funding Acknowledgements Type of funding sources: None. Background The evidence supporting the implantation of implantable cardioverter-defibrillator (ICD) in the primary prevention of sudden cardiac death (SCD) comes mostly from the times when optimal management of heart failure was not as effective as at present. Moreover, the detailed data on the long-term risk of arrhythmias in patients with ICD are scarce. Purpose To present the long-term results of the remote monitoring (RM) of patients with ICD from a large, tertiary cardiovascular centre registry. Methods The clinical data from the time of device implantation were derived from the COMMIT-HF registry, while the follow-up data were obtained from the investigator-initiated RM registry. In brief, the registry encompasses data regarding the types of the transmissions and their contents, with particular emphasis on the occurrence of arrhythmic episodes, device interventions, as well as the data on the causes of other alert transmissions. Results In total, 1,299 patients were included in the analysis. The median follow-up duration of RM was 4.4 years, and the primary indication for implantation was ischemic cardiomyopathy (60.3%). Appropriate antitachycardia pacing (ATP) and high-voltage therapy for ventricular arrhythmias occurred in respectively 25.3% and 26.1% of patients, while inappropriate ATP and HV in respectively 11.5% and 8.7%. The prevalence of AF was 40.8%. Conclusions In a large real-life cohort of continuously remotely monitored patients with ICDs, the percentage of patients with appropriate therapies for ventricular arrhythmias exceeded 25%. Further analyses are necessary to stratify the risk of ventricular arrhythmias in the contemporary practice.

Value of programmed electrical stimulation in Brugada Syndrome: a cohort study

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Prognostic value of programmed electrical stimulation (PES) in Brugada Syndrome (BrS) remains controversial. Substantial controversy exists regarding usefulness of PES in identifying BrS patients at risk of sudden cardiac death (SCD). Implantation of an implantable cardioverter-defibrillator is the only reliable form of SCD prevention in this specific population Purpose To determine if induction of sustained ventricular arrhythmia (VA) in PES is a predictor of cardiac events (CE), defined as the composite of SCD, appropriate ICD therapy for VA or unexplained syncope. Methods A retrospective analysis of 34 patients with spontaneous or pharmacologically induced type 1 Brugada pattern, submitted to electrophysiology study with PES between 2015 and 2019 in a Portuguese Center, was performed. Patients were followed for 24 months. Hospital records and monitoring data from cardiac devices were consulted. The Mann-Whitney U test was used for median comparison between groups. Binary logistic regression through the stepwise method was performed to evaluate categorical features. Results 35% (n=12) and 27% (n=9) had spontaneous type 1 and type 2 Brugada pattern in basal electrocardiography, respectively. 23% (n=8) had VA induced by PES. The mean age was 51,2±12,3 years. 71% (n=24) were male. 15% (n=5) had history of cardiac syncope, and 27% (n=9) had a family history of SCD. 9% (n=3) were carriers of a SNC5A mutation. Mean AH time and HV time were, respectively, 105±31,9, and 49±8,5ms. During the 24 months of follow-up, 9% (n=3) suffered a CE (2 unexplained syncope and 1 SCD). None of the patients who suffered CE had VA inducible at PES study. There was no statistical significance in the occurrence of cardiac events when comparing both groups (VA induced in PES vs. no induced arrhythmia) (p=0,49, OR 0,89, IC 95% 0,70;1,02). Through binary logistics, adjusted for potential confounders (gender, history of syncope, history of family SCD and identification of a genetic variant), patients with spontaneous type 1 Brugada pattern in basal electrocardiography were 2,2 times more likely to have a CE (IC 95% 0,12;40,2). Conclusion In this population, VA induced by PES was not a predictor of CE during the follow-up period, which highlights the difficulty of risk stratification in patients with BrS. New risk-stratification tools are urgently needed to select those patients at higher-risk of SCD, which are candidates for prophylactic ICD implantation.

PO-04-233 MULTIDISCIPLINARY APPROACHES TO TREAT VENTRICULAR ARRHYTHMIAS WITH RADIOABLATION AND CARDIAC SYMPATHECTOMY (MAVERICS)

Ventricular arrhythmias (VAs) are the most lethal arrhythmias. Established therapies to prevent occurrence of VAs include anti-arrhythmic drugs (AADs) and catheter ablation (CA). For patients with recurrent VAs despite AADs and CA, there exist novel treatment modalities such as cardiac sympathetic denervation (CSD) via percutaneous and surgical approach and stereotactic body radiation therapy (SBRT). The current study reports the outcomes of CSD and SBRT from a tertiary care academic center. To report outcomes of CSD and SBRT for treatment of VAs refractory to conventional treatment with AADs and CA. Study comprises all patients undergoing CSD or SBRT at our center from 10/2018 to 10/2021. Patients with less than 2 months of available follow-up data were excluded. Retrospective chart review was performed to collate data for demographics, clinical characteristics, arrhythmia burden before and after novel therapies (maximum 12 months), and complications during study period. Burden of VAs in the form of episodes of anti-tachycardia pacing (ATP) and defibrillator shocks per month were assessed as primary efficacy outcome. Complications during CSD and SBRT were assessed as primary safety outcome. Overall, 25 patients underwent novel therapies for VAs. Thirteen were excluded due to insufficient follow up data. Of 12 included patients, a total of 4, 5, and 3 patients underwent SBRT, CSD, and both CSD/SBRT, respectively. Median age of the study population was 66 years (55-72). The majority of the patients (10/12) were male. Median left ventricular ejection fraction was 30% (25%-34%). Eight patients had non-ischemic cardiomyopathy. Median number of AADs and CA prior to novel therapies was 3 (2-5) and 1 (0-2), respectively. Follow up was available for a median of 12 (12-12) months before and 12 (9-12) months after intervention. Overall, 11 of 12 patients demonstrated a reduction in VA burden. Mean number of ATP and shock episodes was significantly lower after novel therapies (39±43 vs 3±6; p= 0.008). No procedure-related complications were observed during the study period. Incorporation of novel VA treatment modalities is associated with a reduced arrhythmia burden in this single center study. Further studies are warranted to validate these findings.

PO-04-201 A CASE OF PVC OCCURRING RIGHT BUNDLE BRANCH BLOCK AND PR INTERVAL PROLONGED DURING ETHANOL ABLATION VIA THE CORONARY VENOUS SYSTEM

Ethanol ablation via the coronary venous system (CVS) has been reported to be effective and safe as a novel therapy for ventricular arrhythmias, especially for the epicardial and intramural origin sites. Previous studies reported no heart block complications during retrograde coronary venous ethanol ablation, neither atrioventricular block (AVB) nor other types of conductive system block. N/A A 67-year-old female with symptomatic and drug-refractory premature ventricular contractions (PVCs) was admitted for ablation therapy. The PVC burden was 31.7%. The 12-lead ECG showed a PVC with LBBB, inferior axis with a precordial transition in lead V3, and QS pattern in lead I. The QRS duration of PVC was 143ms. The Q-wave ratio of lead aVL/aVR was 1.47. Endocardial mapping was performed using a 3.5mm open-irrigated-tip catheter (ThermoCool, Biosense Webster, CA, USA). The earliest activation time was -8ms and -10ms pre-QRS at the septal aspect of right ventricular outflow tract (RVOT) and the left coronary sinus (LCC), respectively (Fig 1A). Ablation with 35-40W, 45-50°C was attempted but no response. We considered it might be an intramural origin site. The CVS angiography was performed and the ablation catheter was positioned in LCC for reference (Fig 1B). The earliest activation time (-27ms) was mapped in a septal branch of the anterior interventricular vein (AIV) with a 3.3F quadripolar catheter and local pace mapping matched well. Selective angiography confirmed the quadripolar catheter was in the septal branch rather than AIV (Fig 1C-D). A balloon was used to deliver ethanal and prevent its backflow to AIV. 1ml 96% ethanol was infused slowly (Fig 1E-F). PVC was eliminated immediately as soon as the ethanol infusion. But we noticed the PR interval prolonged from 178 to 190ms. More ethanol was injected carefully to consolidate the effect but we stopped infusion after a total of 2.5ml ethanol because the ECG showed complete RBBB and PR interval prolonged further to 202ms. RBBB and I° AVB were persistent during the whole hospitalization for 3 days. However, at 1-month follow-up, the QRS morphology returned to normal and the PR interval shortened to 172ms (Fig 1G). 24-hour Holter showed no recurrence. Ethanol ablation via the CVS also might induce heart block complications due to the adjacent anatomical position with the conductive system, even though it might be reversible. Operators should be cognizant of the potential risk.

Subcutaneous and Transvenous Defibrillators in Arrhythmogenic Right Ventricular Cardiomyopathy: A Comparison of Clinical and Quality-of-Life Outcomes.

There is limited evidence guiding the selection between subcutaneous and transvenous implantable cardioverter-defibrillators (ICDs) in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) at risk for sudden death. This study aimed to compare clinical and quality-of-life outcomes between transvenous and subcutaneous ICDs among patients with ARVC. Patients with a subcutaneous ICD (n=57) were matched to patients with a transvenous ICD (n=88) based on sex, proband status, primary prevention or secondary prevention, monomorphic ventricular tachycardia before implantation, and year of implantation. Appropriate therapy for ventricular arrhythmia, inappropriate shocks, and complications were compared. Quality-of-life surveys were conducted annually. The matched cohort (median age of 35 years, 43% men, 78% proband, and 37% secondary prevention device) were prospectively followed for 5.1 ± 2.5 years. No significant difference was observed in the rate of appropriate ICD shocks. The subcutaneous group had more inappropriate shocks (23% vs 10%) and fewer procedure-related complications (4% vs 14%) than the transvenous group (P< 0.05). The association between ICD type and the composite of inappropriate shock and complication was not statistically significant (subcutaneous vs transvenous adjusted HR: 1.43; 95%CI: 0.72-2.84). A subcutaneous ICD was associated with more body image concerns and range of motion than a transvenous ICD (P< 0.05). In patients with ARVC receiving an ICD, the risk of inappropriate shocks from a subcutaneous ICDshould be balanced against the significant vascular complication risk from a transvenous ICD. Patients with a subcutaneous ICD had more concerns for body image and range of motion.

Abstract 13956: Multidisciplinary Approaches to Treat Ventricular Arrhythmias With Radioablation and Cardiac Sympathectomy (MAVERICS)

Background: Ventricular arrhythmias (VAs) are the most lethal arrhythmias. Established therapies to prevent VAs include anti-arrhythmic drugs (AADs) and catheter ablation (CA). For patients with recurrent VAs despite AADs and CA, novel therapies such as cardiac sympathetic denervation (CSD) and stereotactic body radiation therapy (SBRT) exist. This study reports outcomes of CSD and SBRT at a tertiary care academic center. Methods: Study comprises all patients undergoing CSD or SBRT at one center from 10/2018 - 10/2021. Patients with less than 2 months of follow-up were excluded. Retrospective chart review was performed to collate data for demographics, clinical characteristics, arrhythmia burden before and after novel therapies (maximum 12 months), and treatment complications. VA burden in the form of anti-tachycardia pacing (ATP) episodes and defibrillator shocks was assessed as primary efficacy outcome. Treatment complications were assessed as primary safety outcome. Results: Overall, 25 patients underwent novel therapies for VAs, and 13 were excluded for insufficient follow up. Five, 4, and 3 patients underwent CSD, SBRT, and both, respectively. Median age was 66 years (55-72), and 10 (83%) were male. Median left ventricular ejection fraction was 30% (25%-34%). Four patients (33%) had ischemic cardiomyopathy. Median number of AADs and CA prior to novel therapies was 3 (2-5) and 1 (0-2), respectively. Follow up was available for a median of 12 (12-12) months before and 12 (9-12) months after treatment. Overall, VA burden was reduced in 11 of 12 patients (Figure 1). Mean number of ATP and shock episodes was significantly lower after novel therapies (39±43 vs 3±6; p= 0.008). No procedure-related complications were observed. Conclusion: Novel VA treatment modalities are associated with a significantly reduced arrhythmia burden in this single center study. There is a promising role of these therapies as an adjunct to the existing treatment modalities of CA and AADs.

Abstract 9276: Subcutaneous and Transvenous Defibrillator in Arrhythmogenic Right Ventricular Cardiomyopathy

Introduction: There is limited evidence guiding the selection between subcutaneous and transvenous ICD in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) at risk for sudden death.Hypothesis: We aimed to compare clinical and quality of life outcomes between transvenous and subcutaneous implantable defibrillators (ICD) among patients with ARVC. Methods: Patients with subcutaneous ICD (n=57) were matched to patients with transvenous ICD (n=88) based on sex, proband status, primary prevention or secondary prevention, monomorphic ventricular tachycardia before implant, and year of implant. Appropriate therapy for ventricular arrhythmia, inappropriate shocks, and complications were compared. Quality of life surveys were conducted annually. Results: The matched cohort (median age of 35 years, 43% male, 78% proband, and 37% secondary prevention device) were prospectively followed for 5.1 (+/-2.5) years. No significant difference was observed in the rate of appropriate ICD shocks. The subcutaneous group had more inappropriate shocks (23% versus 10%) and fewer procedure related complications (4% versus 14%) than the transvenous group (p &lt;0.05). The association between ICD type and the composite of inappropriate shock and complication was not statistically significant (adjusted hazard ratio 1.43 subcutaneous vs. transvenous, 95% confidence interval 0.72-2.84). Subcutaneous ICD was associated with more body image concerns and range of motion than transvenous ICD (p &lt;0.05). Conclusions: In patients with ARVC receiving an ICD, the risk of inappropriate shocks from subcutaneous ICD should be balanced against the significant vascular complication risk from transvenous ICD. Patients with subcutaneous ICD had more concerns for body image and range of motion.

Abstract 15279: Ablation or Antiarrhythmic Drugs Alone in the Treatment of Ventricular Storm

Introduction: Ventricular storms are managed with a combination of antiarrhythmic drugs (AAD) and ablation therapy. This study examines outcomes in patients who required cardiac intensive care unit (CICU) admission for ventricular storms. Methods: A retrospective cohort study was conducted of 200 random adult patients who admitted to the CICU at Mayo Clinic Rochester in 2016-2017 for ventricular storm. Continuous variables were analyzed with the Mann-Whitney U test. Categorical variables were analyzed with Fisher's exact test. Results: Of the 200 patients, 33 (16.5%) patients underwent ablation and AAD therapy for ventricular arrhythmias; 167 underwent AAD therapy alone. The patients in the ablation group were significantly younger (median of 60.3 vs. 72.7, U=1570, p&amp;lt;.001), had a lower Charlson Comorbidity Index (3.56 vs. 5.21, U=1916, p=.005), and a higher BMI (31.6 vs. 28.2, U=2028, p=.032). There was no difference in sex and race (white vs. non-white) between the two groups. The patients in the ablation groups had a significantly lower in-hospital mortality (0% vs. 20%, p=.001) and higher 1-year survival (91% vs. 63%, p=.001). There was no difference in length of stay in the CICU, length of stay in the hospital, or rate of hospital readmission within one year of discharge. Conclusions: Our study indicates that critically ill patients who undergo ablation and AAD for ventricular arrhythmias have decreased mortality compared to patients who underwent AAD therapy alone. More research is needed to elucidate whether this survival benefit is secondary to differences in treatment or baseline comorbidities in the two groups. Table 1: Characteristics and outcomes of patients undergoing ventricular storm treatment. Data is reported either as median or number of occurrences (%). Antiarrhythmic drug (AAD), Charlson Comorbidity Index (CCI), Body Mass Index (BMI), Cardiac Intensive Care Unit (CICU), Length of Stay in days (LOS). * Significance with p values &amp;lt; .05

Ventricular activation time as a marker for complex ventricular arrhythmias, sudden cardiac death and ICD implantation in hypertrophic cardiomyopathy

Abstract Background Identification of patients with hypertrophic cardiomyopathy (HCM) who are at high risk of sudden cardiac death (SCD) is essential, as life-threatening ventricular arrhythmias (VAs) can be effectively prevented with an implantable cardioverter defibrillator (ICD). Risk stratification using HCM Risk-SCD score is recommended in the 2014 ESC guidelines for the management of patients with HCM. However, the role of electrocardiogram (ECG) in risk stratification is less well established. Purpose We investigated the association between the ventricular activation time (VAT), an ECG marker of the duration of ventricular depolarization, with the HCM Risk-SCD score, the presence of complex VAs, the implantation of an ICD and ICD-therapy for VAs. Methods Patients with a history of HCM, documented by echocardiography, were studied. The 12-lead ECG and echocardiography were performed on the same day. On ECG, we evaluated the VAT in milliseconds, between the onset of the QRS complex to the peak of R wave on V5 or V6 precordial ECG leads. A careful personal and family history for unexplained syncope and SCD was obtained, respectively. The presence of non-sustained ventricular tachycardia (NSVT) and ICD therapy were assessed either with 48h ECG recording or ICD interrogation. HCM Risk-SCD score was calculated by the corresponding ESC online calculator. Statistical analysis was performed using the SPSS software. Results Thirty-three patients with HCM were included (mean age 51±12 years, 78.8% male). According to the HCM Risk-SCD score, HCM patients were divided into three groups: low-risk (&amp;lt;4, 45.5%), intermediate-risk (4 to &amp;lt;6, 24.2%) and high-risk (&amp;gt;6, 30.3%) for SCD. Approximately half of the HCM patients had episodes of NSVT (48.5%) and an ICD (48.5%). Ventricular activation time was significantly prolonged in high-risk group compared either with intermediate-risk (74±24.5 vs 48.7±16.4, p=0.006) or low-risk (74±24.5 vs 44.3±12.6, p&amp;lt;0.001). HCM patients with NSVT had a significantly prolonged VAT compared with those without NSVT (62.19±25.2 vs 47.06±15.3, p=0.022). Moreover, HCM patients with an ICD had a higher VAT than those without an ICD (62.1±25.2 vs 47±15.3, p=0.003). VAT was also significantly prolonged in the group with appropriate ICD therapy for VAs compared with that without ICD therapy (82.8±22.1 vs 52.2±16.4, p=0.007). Finally, there was a significant positive correlation between VAT and NSVT (r=0.352, p=0.044), history of syncope (r=0.604, p&amp;lt;0.001), HCM risk-SCD score (r=0.493, p=0.004), ICD implantation (r=0.508, p=0.003) and ICD therapy (r=0.648, p=0.007) for VAs while there was not a correlation with the family history of SCD. Conclusion Prolongation of VAT is associated with NSVT, HCM risk score for SCD, ICD implantation and ICD therapy for VAs in patients with HCM and it seems to be a novel, easy to measure, ECG marker for risk stratification. Funding Acknowledgement Type of funding sources: None.

The role of trigger factors in the occurrence of appropriate ICD shocks and their prognostic implications

Abstract Background The role of triggers in the occurrence of appropriate ICD shocks due to ventricular tachyarrhythmias is not well known. The aim of the study was to assess the prevalence of trigger factors in appropriate ICD shocks and to analyze their prognostic impact on clinical outcome. Methods A total of 710 consecutive patients of a prospective single-centre ICD-registry who received a first appropriate ICD shock between 2000 and 9/2021 were analyzed. Results In 35% of ICD patients with first ICD shock, at least one of the following triggers was found: Ischemia (22%), Compliance (9%), Decompensation (38%), Stress (12%), Technical (5%), Electrolyte/endocrinological disorder (22%) and Medication intoxication (4%) (Table 1). The trigger factors can be summarized under the acronym ICD-STEMi. Patients with trigger associated ICD shocks had a more depressed ejection fraction and presented more often with ventricular fibrillation or electrical storm. The therapy after VT/VF shock in the trigger group comprised trigger optimization in 100% and heart failure optimization in 21% as compared to 0% respectively 10% in the no-trigger group (p&amp;lt;0.001). The ventricular arrhythmia therapy (antiarrhythmics or VT ablation) was not different between both groups (35% in each group). Patients with triggered first ICD shock had an increased 5-year mortality rate (50% versus 38%, p&amp;lt;0.001) (Figure 1). Conclusions In one third of ICD patients with first appropriate ICD shock, at least one trigger can be identified. Finding a trigger strongly influenced therapy after VT/VF shock. Patients with triggered ICD shock have a higher 5-year mortality rate. The evaluation of trigger factors after the occurrence of ICD shocks is mandatory and can be systematically evaluated using the acronym ICD-STEMi. Funding Acknowledgement Type of funding sources: None.

Cardiopulmonary exercise testing for cardiovascular risk assessment in patients undergoing gastric and oesophageal cancer surgery: results from a prospective interventional cohort study

BackgroundCardiopulmonary exercise testing (CPET) has shown to be useful for preoperative risk stratification in various types of intra-abdominal and thoracic surgery. However, data about the predictive value of CPET for...

Underrepresentation of women in implantable cardioverter defibrillator trials

There are sex differences in the epidemiology and presentation of ventricular arrhythmias. Sudden cardiac death (SCD) is less common in women than in men. Women have been under-represented in implantable cardioverter defibrillator (ICD) trials evaluating the benefit of ICD therapy for primary and secondary prevention of SCD. Following ICD implantation, women are less likely to experience appropriate ICD therapy for ventricular arrhythmias, consistent with epidemiological findings of a lower rate of SCD in women. Sex differences in ICD implantation rates have also been noted for primary and secondary prevention of SCD in registries and large observational cohort studies. Reasons for these differences are unclear. Age and comorbidities at the time of presentation may be partially responsible, although sex bias, patient preference, or contribution of social determinants of health cannot be excluded. There are many unanswered questions regarding reasons for sex differences in ICD usage and under-representation of women in clinical device trials. Additional investigation is needed to better understand these differences to improve outcome of all patients who are at risk for sudden cardiac arrest.

Sex Difference in Arrhythmic Risks and Prognosis in Patients with Nonischemic Cardiomyopathy

Background: Heart failure (HF) carries high mortality and comorbidities. Guidelines-directed medical and device therapy improves prognosis significantly. Although automatic intracardiac defibrillator (AICD) had 50% relative reduction in sudden cardiac deaths in patients with nonischemic cardiomyopathy (NICMP), there is no significant difference in overall mortality. Subgroup analysis of the two randomized controlled NICMP trials indicates no significant mortality benefits in female patients. Subjects and Methods: This single-center, retrospective study recruited 447 patients with HF and left ventricular ejection fraction (LVEF) &lt;40% due to NICMP etiology, and those with significant coronary artery disease with more than 70% stenosis were excluded based on coronary angiogram. The primary endpoint was appropriate therapy from the device for ventricular arrhythmias and primary composite endpoints included death, appropriate therapy from device for ventricular arrhythmias and hospitalization for HF. Results: Female patients were older, had smaller left ventricles, narrower QRS, and higher LVEF at baseline. The mean follow-up duration was 6.18 ± 4.16 years. There were 61 deaths (13% vs. 2.20% deaths per year, 20 females and 41 males). Mean LVEF increased significantly from 24.88 ± 8.17% to 39.92 ± 13.88% in female patients and from 22.05 ± 8.52% to 36.14 ± 8.17% in male patients (P = 0.023). LVEF increased to or more than 35% in 190 patients (43%). Forty patients (9%) received AICD or cardiac resynchronization therapy and the other 81% received primary prevention. The median time from diagnosis of NICMP to appropriate device therapy for ventricular arrhythmias was 7.13 years (interquartile range 2.92–10.92 years). All the device therapy occurred in patients with LVEF &lt;35%. 18/21 patients (86%) had appropriate therapy for ventricular arrhythmias were males. Male patients also had significantly higher composite endpoints (P = 0.0022). Conclusions: Guidelines-directed medical therapy improves left ventricular systolic function, reduces arrhythmic risks, and improves prognosis. The arrhythmic risk and composite endpoints are significantly higher in male than female patients.

Efficacy and Safety of Appropriate Shocks and Antitachycardia Pacing in Transvenous and Subcutaneous Implantable Defibrillators: Analysis of All Appropriate Therapy in the PRAETORIAN Trial.

The PRAETORIAN trial (A Prospective, Randomized Comparison of Subcutaneous and Transvenous Implantable Cardioverter Defibrillator Therapy) showed noninferiority of subcutaneous implantable cardioverter defibrillator (S-ICD) compared with transvenous implantable cardioverter defibrillator (TV-ICD) with regard to inappropriate shocks and complications. In contrast to TV-ICD, S-ICD cannot provide antitachycardia pacing for monomorphic ventricular tachycardia. This prespecified secondary analysis evaluates appropriate therapy and whether antitachycardia pacing reduces the number of appropriate shocks. The PRAETORIAN trial was an international, investigator-initiated randomized trial that included patients with an indication for implantable cardioverter defibrillator (ICD) therapy. Patients with previous ventricular tachycardia <170 bpm or refractory recurrent monomorphic ventricular tachycardia were excluded. In 39 centers, 849 patients were randomized to receive an S-ICD (n=426) or TV-ICD (n=423) and were followed for a median of 49.1 months. ICD programming was mandated by protocol. Appropriate ICD therapy was defined as therapy for ventricular arrhythmias. Arrhythmias were classified as discrete episodes and storm episodes (≥3 episodes within 24 hours). Analyses were performed in the modified intention-to-treat population. In the S-ICD group, 86 of 426 patients received appropriate therapy, versus 78 of 423 patients in the TV-ICD group, during a median follow-up of 52 months (48-month Kaplan-Meier estimates 19.4% and 17.5%; P=0.45). In the S-ICD group, 83 patients received at least 1 shock, versus 57 patients in the TV-ICD group (48-month Kaplan-Meier estimates 19.2% and 11.5%; P=0.02). Patients in the S-ICD group had a total of 254 shocks, compared with 228 shocks in the TV-ICD group (P=0.68). First shock efficacy was 93.8% in the S-ICD group and 91.6% in the TV-ICD group (P=0.40). The first antitachycardia pacing attempt successfully terminated 46% of all monomorphic ventricular tachycardias, but accelerated the arrhythmia in 9.4%. Ten patients with S-ICD experienced 13 electrical storms, versus 18 patients with TV-ICD with 19 electrical storms. Patients with appropriate therapy had an almost 2-fold increased relative risk of electrical storms in the TV-ICD group compared with the S-ICD group (P=0.05). In this trial, no difference was observed in shock efficacy of S-ICD compared with TV-ICD. Although patients in the S-ICD group were more likely to receive an ICD shock, the total number of appropriate shocks was not different between the 2 groups. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01296022.

Real-world evaluation of follow up strategies after implantable cardiac-defibrillator therapies in patients with ventricular tachycardia (REFINE-VT)

Abstract Introduction Implantable cardiac-defibrillators (ICD) can prevent sudden cardiac death but the risk of recurrent ventricular arrhythmia (VA) and ICD therapies persists. Established strategies to minimize such risks include medication optimization, device reprogramming or ventricular tachycardia (VT) catheter ablation (CA). However, the timing and choice of these strategies at ICD follow-up may not be as consistent in the real-world as the regulated conditions of clinical trials. Furthermore, whether these decisions at follow-up are influenced by the type of arrhythmia, ICD therapy or patient characteristics remain unclear. Purpose We evaluated ICD follow-up strategies in patients with ischaemic (ICM) and non-ischaemic cardiomyopathy (NICM) to refine the outpatient management of these complex patients and ultimately improve overall patient outcome. Methods REFINE-VT is a retrospective study of 514 patients with ICD/CRT-D who attended ICD follow-up between June 2018 to September 2019 at the University Hospital Coventry &amp; Warwickshire (UHCW) tertiary cardiology department. All follow-ups were face-to-face. Patients were divided into 2 groups according to the absence or presence of sustained VA (e.g. &amp;gt;30 seconds of VT and/or appropriate ICD therapy), described as “negative event” and “positive event” groups respectively. The type of strategy employed in response to a positive event were categorized into 4 groups: (1) Medication change only (2) Device programming +/− medication (3) Referral for VT CA (4) No intervention Results 514 consecutive patients with ICD (52%) or CRT-D (48%) were analysed. Overall mean age was 67±14 years with 79% male patients. ICM was diagnosed in 329 (64%) patient and NICM in 185 (36%). 437 (85%) patients had no significant VA and/or ICD therapy referred to as the negative group. A total of 77 patients (15%) suffered VA and/or ICD therapies, of whom 22 patients (26%) experienced a second event. 31% (n=24) of this positive event group received no preventative strategy (Table 1). We observed an inconsistent approach to the choice of strategies across different types of arrhythmias and ICD therapies. E.g. the odds of intervening were significantly higher if ICD shock was detected compared to anti-tachycardia pacing (OR 8.4, 95% CI 1.7–39.6, p=0.007). Even in patients with two events, the rate of referral for VT ablation and escalation of antiarrhythmics were similarly as low as patients with a single event (Table 2). Conclusion This is the first contemporary study that has evaluated how strategies that reduce the risk of recurrent ICD events are executed in a real-world population. We have demonstrated that the decision to intervene and choices of strategy remain inconsistent and partially biased by the type of arrhythmia and ICD therapy at follow-up. This supports the need for an evidence-driven multi-disciplinary VT clinic to refine and standardize our approach to this heterogeneous population. Funding Acknowledgement Type of funding sources: None.