P463Risk assessment for primary prophylactic ICD implantation in hypertrophic cardiomyopathy using the risk calculator: discrepancy between theory and clinical practice?

Abstract Aims According to current guidelines, defibrillation testing (DT) for efficacy can be omitted in patients undergoing transvenous implantable cardioverter–defibrillator (T-ICD) implantation. DT is still recommended for patients at risk for a high defibrillation threshold (e.g. hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, right-sided implantations) and for ICD generator changes. Moreover, a class I recommendation remains to perform DT during the implantation of subcutaneous ICD (S-ICD). The aim of the present survey was to analyze the current practice of DT during T-ICD and S-ICD implantations in Italy. Methods In March 2021, an ad hoc questionnaire on the current performance of DT and the standard practice adopted during testing was completed by 72 operators at Italian centers implanting S-ICD and T-ICD. Results 48 (67%) operators reported never performing DT during de-novo T-ICD implantations, while no operators perform it systematically. The remaining respondents perform it in specific cases: right sided implantations (54%), poor signal sensing (46%), secondary prevention patients (42%), arrhythmic syndromes (13%), hypertrophic cardiomyopathy (8%). DT is never performed at T-ICD generator change. At the time of de-novo S-ICD implantation, DT is never performed by 9 (13%) operators and performed systematically by 48 (66%). The remaining operators perform DT in cases of: secondary prevention patients (73%), sub-optimal S-ICD placement (33%), non-compromised ejection fraction (33%) or obese patients (7%). DT is not performed at S-ICD generator change by 92% of operators. DT is conducted by delivering a first shock energy of 65J by 60% of operators, while the remaining 40% test lower energy values. The most frequently reported conditions for revising the system at the end of de- novo implantation procedure is high shock impedance (54%) and sub-optimal S-ICD placement or high PRAETORIAN score (50%). With adequately low shock impedance and optimal system placement, 37% of operators would accept a defibrillation margin <15J. Conclusion In current clinical practice, the vast majority of operators omit DT at T-ICD implantation, even when still recommended in the guidelines. DT is also frequently omitted at S-ICD implantation. We also report a wide variability among operators in the procedures followed during DT and in the criteria applied for defining the procedural success. FUNDunding Acknowledgement Type of funding sources: None.

Download Full-text

B-AB11-03 OMISSION OF DEFIBRILLATION TESTING DURING S-ICD IMPLANTATION IN CLINICAL PRACTICE: FOLLOW UP ANALYSIS

Heart Rhythm ◽

10.1016/j.hrthm.2021.06.066 ◽

2021 ◽

Vol 18 (8) ◽

pp. S21

Author(s):

Valter Bianchi ◽

Giovanni Bisignani ◽

Gerardo Nigro ◽

Federico Migliore ◽

Gianfranco Tola ◽

...

Keyword(s):

Clinical Practice ◽

Icd Implantation

Download Full-text

Baseline clinical features in a large-scale registration survey of patient with hypertrophic cardiomyopathy throughout Japan: J-HCM registry study

European Heart Journal ◽

10.1093/ehjci/ehaa946.2085 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

T Kubo ◽

H Takano ◽

M Takayama ◽

Y.L Doi ◽

Y Minami ◽

...

Keyword(s):

Hypertrophic Cardiomyopathy ◽

Clinical Features ◽

Clinical Characteristics ◽

Large Scale ◽

Risk Group ◽

Nyha Class ◽

Left Ventricular ◽

Registry Study ◽

Icd Implantation ◽

Successful Recovery

Abstract Background Hypertrophic cardiomyopathy (HCM) is a most prevalent primary myocardial disorder with heterogeneous clinical features. However, there have been few studies on clinical features of HCM as a prospective cohort. In 2015, we established a large-scale registration survey of patients with HCM throughout Japan, named J-HCM registry study. Purpose The aim of this study was to clarify the clinical features of Japanese patients with HCM. Methods J-HCM registry study is a prospective, multicenter investigation, consisting of 24 hospitals. This time, we present the baseline clinical characteristics in this survey. Results Total 1484 patients were registered. The ages at registration and at diagnosis were 65±15 and 56±17 years, respectively, and 806 patients (54%) were men. Majority of the patients (95%) was NYHA class I or II. With regard to subtypes of HCM, there were 526 patients (36%) in the HCM with left ventricular (LV) outflow tract obstruction, 126 patients (8%) in the mid-ventricular obstruction, 57 patients (4%) in the end-stage phase characterized by LV ejection fraction <50%, and 197 patients (14%) in apical HCM. At registration, 80 patients (6%) had prior successful recovery from sustained ventricular tachycardia or ventricular fibrillation, 162 patients (11%) suffered from heart failure hospitalization, and 64 patients (4%) had history of embolic event. Regarding invasive treatment, 160 patients (10%) had prior septal reduction therapy and 162 patients (11%) had ICD implantation. According to the 2014 European Society of Cardiology Guidelines on sudden cardiac death (SCD) prevention, the study patients were divided into 3 categories by the HCM Risk-SCD calculator: patients distribution, 4% in the high risk group (≥6% calculated HCM Risk-SCD at 5 years), 7% in the intermediate risk group (4% to <6%), 69% in the low risk group (<4%), and 16% in the patients with extreme characteristics (Figure 1). Conclusions In this multicenter registration survey of patients with HCM, the baseline clinical characteristics were almost similar to several retrospective large-scale cohorts in Western countries except older age and less symptomatic state. This study will provide important knowledge regarding management of HCM. Figure 1 Funding Acknowledgement Type of funding source: None

Download Full-text

Worldwide differences in primary prevention implantable cardioverter defibrillator utilization and outcomes in hypertrophic cardiomyopathy

European Heart Journal ◽

10.1093/eurheartj/ehab598 ◽

2021 ◽

Author(s):

Victor Nauffal ◽

Peter Marstrand ◽

Larry Han ◽

Victoria N Parikh ◽

Adam S Helms ◽

...

Keyword(s):

Hypertrophic Cardiomyopathy ◽

Primary Prevention ◽

Implantable Cardioverter Defibrillator ◽

Cox Proportional Hazards ◽

Icd Implantation ◽

Icd Therapy ◽

Cardioverter Defibrillator ◽

Significant Difference ◽

Implantation Rates ◽

The Impact

Abstract Aims Risk stratification algorithms for sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM) and regional differences in clinical practice have evolved over time. We sought to compare primary prevention implantable cardioverter defibrillator (ICD) implantation rates and associated clinical outcomes in US vs. non-US tertiary HCM centres within the international Sarcomeric Human Cardiomyopathy Registry. Methods and results We included patients with HCM enrolled from eight US sites (n = 2650) and five non-US (n = 2660) sites and used multivariable Cox-proportional hazards models to compare outcomes between sites. Primary prevention ICD implantation rates in US sites were two-fold higher than non-US sites (hazard ratio (HR) 2.27 [1.89–2.74]), including in individuals deemed at high 5-year SCD risk (≥6%) based on the HCM risk-SCD score (HR 3.27 [1.76–6.05]). US ICD recipients also had fewer traditional SCD risk factors. Among ICD recipients, rates of appropriate ICD therapy were significantly lower in US vs. non-US sites (HR 0.52 [0.28–0.97]). No significant difference was identified in the incidence of SCD/resuscitated cardiac arrest among non-recipients of ICDs in US vs. non-US sites (HR 1.21 [0.74–1.97]). Conclusion Primary prevention ICDs are implanted more frequently in patients with HCM in US vs. non-US sites across the spectrum of SCD risk. There was a lower rate of appropriate ICD therapy in US sites, consistent with a lower-risk population, and no significant difference in SCD in US vs. non-US patients who did not receive an ICD. Further studies are needed to understand what drives malignant arrhythmias, optimize ICD allocation, and examine the impact of different ICD utilization strategies on long-term outcomes in HCM.

Download Full-text

Abstract 11447: Low Incidence of Appropriate Therapy Following Defibrillator Implantation for Primary Prevention of Sudden Cardiac Death in Hypertrophic Cardiomyopathy

Circulation ◽

10.1161/circ.132.suppl_3.11447 ◽

2015 ◽

Vol 132 (suppl_3) ◽

Author(s):

Amalie C Thavikulwat ◽

Todd T Tomson ◽

Bradley P Knight ◽

Robert O Bonow ◽

Lubna Choudhury

Keyword(s):

Risk Factors ◽

Risk Factor ◽

Hypertrophic Cardiomyopathy ◽

Primary Prevention ◽

Sudden Cardiac Death ◽

Secondary Prevention ◽

Cardiac Death ◽

Icd Implantation ◽

Icd Therapy ◽

Appropriate Therapy

Introduction: Hypertrophic cardiomyopathy (HCM) is a leading cause of sudden cardiac death (SCD) in young adults. Implantable cardioverter defibrillators (ICD) effectively terminate ventricular tachycardia (VT) and fibrillation (VF) that cause SCD, but the reported prevalence of and patient characteristics leading to appropriate ICD therapy in HCM have been variable. Hypothesis: We hypothesized that some risk factors may be more prevalent than others in patients with HCM who receive appropriate ICD therapy and that the overall incidence of appropriate therapy may be lower than that reported previously. Methods: We retrospectively studied all patients with HCM who were treated with ICDs at our referral center from 2000-2013 to determine the rates of appropriate and inappropriate ICD therapies. Results: Of 1136 patients with HCM, we identified 135 who underwent ICD implantation (125 for primary and 10 for secondary prevention), aged 18-81 years (mean 48±17) at the time of implantation. The mean follow-up time was 5.2±4.5 years. Appropriate ICD intervention occurred in 20 of 135 patients (2.8%/year) by providing a shock or antitachycardia pacing in response to VT or VF. The annual rate of appropriate ICD therapy was 2.4%/year for primary and 7.2%/year for secondary prevention devices. Commonly used risk factors were equally prevalent among patients who received appropriate therapy and those who did not; furthermore, the likelihood of receiving appropriate therapy in the presence of each risk factor was similar (Figure). Inappropriate ICD therapy occurred in 27 patients (3.8%/year). Conclusions: ICDs provide clear benefit to patients who experience life-threatening arrhythmias, particularly those being treated for secondary prevention. However, the appropriate therapy rate for primary prevention was lower than previously reported, and no single risk factor appeared to have stronger association with appropriate ICD therapy than others.

Download Full-text

P521Conversion test during Subcutaneous Implantable Cardioverter-Defibrillator Implantation in clinical practice: in-hospital and mid-term outcome

EP Europace ◽

10.1093/europace/euaa162.118 ◽

2020 ◽

Vol 22 (Supplement_1) ◽

Author(s):

V Bianchi ◽

I Diemberger ◽

V Tavoletta ◽

L Perrotta ◽

L Ottaviano ◽

...

Keyword(s):

Clinical Practice ◽

Ejection Fraction ◽

Systolic Function ◽

Implantable Cardioverter Defibrillators ◽

Icd Implantation ◽

Serious Adverse Events ◽

Term Outcome ◽

Appropriate Shocks ◽

Ct Data

Abstract Funding Acknowledgements No funding OnBehalf RHYTHM DETECT Registry Background With subcutaneous implantable cardioverter–defibrillators (S-ICD), conversion test (CT) is still recommended at implantation. However, prior works found that adherence to this recommendation is declining in clinical practice. Purpose To describe current practice regarding CT at S-ICD implantation, and also measure in-hospital outcome of patients who underwent CT and mid-term outcome of patients without CT. Methods We analyzed 1652 consecutive patients (49 ± 15 years old, 80% male, 51% with ischemic or non-ischemic dilated cardiomyopathy, 45% with ejection fraction ≤35%) who underwent S-ICD implantation in 60 Italian centers from 2013 to 2019. Results CT data were missing in 27 patients. CT was performed in 1300 patients. Successful conversion with ≤65J was obtained in 97.4% of patients. Shock at 80J was not effective in 12 (0.9%) patients. In 10 of these patients the CT was successful after device repositioning, while in 2 patients it was decided to implant a transvenous ICD. Two (0.15%) episodes of electromechanical dissociation (1 fatal) were reported as consequence of CT. CT was not performed in 325 patients (for clinical reasons in 182 patients, for facility preference in 71, ventricular fibrillation not inducible in 72 patients). As compared to the CT group, these patients were older (51 ± 16 vs. 48 ± 15 years; p < 0.01) and had lower ejection fraction (37 ± 16% vs. 46 ± 16%; p < 0.01). 243 non-CT patients had at least 6 months follow-up (median 15 months). In this group, 12 (4.9%) patients had appropriate shocks to treat VT/VF (all successfully terminated with the first shock), and 9 (3.7%) patients had inappropriate shocks. Conclusions This analysis showed that CT is frequently omitted in current clinical practice, especially in older patients with worse systolic function. Shocks at CT are very frequently effective and system revision after CT is rarely required. CT is also safe, although serious adverse events cannot be excluded. A strategy that omits CT did not appear to compromise the effectiveness of the S-ICD, but larger populations and longer follow-up are needed to confirm this finding.

Download Full-text

P1291 Are we ready for machine learning in HCM risk stratification?

European Heart Journal - Cardiovascular Imaging ◽

10.1093/ehjci/jez319.736 ◽

2020 ◽

Vol 21 (Supplement_1) ◽

Author(s):

D M Adamczak ◽

M Bednarski ◽

A Rogala ◽

M Antoniak ◽

T Kiebalo ◽

...

Keyword(s):

Machine Learning ◽

High Risk ◽

Risk Group ◽

Ventricular Myocardium ◽

Left Ventricular ◽

High Risk Group ◽

Machine Learning Algorithms ◽

Left Ventricular Myocardium ◽

Risk Calculator ◽

Icd Implantation

Abstract BACKGROUND Hypertrophic cardiomyopathy (HCM) is a heart disease characterized by hypertrophy of the left ventricular myocardium. The disease is the most common cause of sudden cardiac death (SCD) in young people and competitive athletes due to fatal ventricular arrhythmias, but in most patients, however, HCM has a benign course. Therefore, it is of the utmost importance to properly evaluate patients and identify those who would benefit from a cardioverter-defibrillator (ICD) implantation. The HCM SCD-Risk Calculator is a useful tool for estimating the 5-year risk of SCD. Parameters included in the model at evaluation are: age, maximum left ventricular wall thickness, left atrial dimension, maximum gradient in left ventricular outflow tract, family history of SCD, non-sustained ventricular tachycardia and unexplained syncope. Patients’ risk of SCD is classified as low (<4%), intermediate (4-<6%) or high (≥6%). Those in the high-risk group should have an ICD implantation. It can also be considered in the intermediate-risk group. However, the calculator still needs improvement and machine learning (ML) has the potential to fulfill this task. ML algorithm creates a model for solving a specific problem without explicit programming - instead it relies only on available data - by discovering patterns and relations. METHODS 252 HCM patients (aged 20-88 years, 49,6% were men) treated in our Department from 2005 to 2018, have been enrolled. The follow-up lasted 0-13 years (average: 3.8 years). SCD was defined as sudden cardiac arrest (SCA) or an appropriate ICD intervention. All parameters from HCM SCD-Risk Calculator have been obtained and the risk of SCD has been calculated for all patients during the first echocardiographic evaluation. ML model with variables from HCM SCD-Risk Calculator has been created. Both methods have been compared. RESULTS 20 patients reached an SCD end-point. 1 patient died due to SCA and 19 had an appropriate ICD intervention. Among them, there were respectively 6, 7 and 7 patients in the low, intermediate and high-risk group of SCD. 1 patient, who died, had a low risk. The ML model correctly assessed the SCD event only in 1 patient. According to ML, the risk of SCD ≤2.07% was a negative predictor. CONCLUSIONS The study did not show an advantage of ML over HCM SCD-Risk Calculator. Because of the characteristic of the dataset (approximately the same number of features and observations), the selection of machine learning algorithms was limited. Best results (evaluated using LOOCV) were achieved with a decision tree. We expect that bigger dataset would allow improving model performance because of strong regularization need in the current setup.

Download Full-text

Cardiovascular genetics: the role of genetic testing in diagnosis and management of patients with hypertrophic cardiomyopathy

Heart ◽

10.1136/heartjnl-2020-316798 ◽

2020 ◽

pp. heartjnl-2020-316798

Author(s):

Monica Ahluwalia ◽

Carolyn Y Ho

Keyword(s):

At Risk ◽

Clinical Practice ◽

Genetic Testing ◽

Hypertrophic Cardiomyopathy ◽

Clinical Manifestations ◽

Left Ventricular ◽

Family Management ◽

Panel Testing ◽

Pathogenic Variants ◽

Gene Panel Testing

Genetic testing in hypertrophic cardiomyopathy (HCM) is a valuable tool to manage patients and their families. Genetic testing can help inform diagnosis and differentiate HCM from other disorders that also result in increased left ventricular wall thickness, thereby directly impacting treatment. Moreover, genetic testing can definitively identify at-risk relatives and focus family management. Pathogenic variants in sarcomere and sarcomere-related genes have been implicated in causing HCM, and targeted gene panel testing is recommended for patients once a clinical diagnosis has been established. If a pathogenic or likely pathogenic variant is identified in a patient with HCM, predictive genetic testing is recommended for their at-risk relatives to determine who is at risk and to guide longitudinal screening and risk stratification. However, there are important challenges and considerations to implementing genetic testing in clinical practice. Genetic testing results can have psychological and other implications for patients and their families, emphasising the importance of genetic counselling before and after genetic testing. Determining the clinical relevance of genetic testing results is also complex and requires expertise in understanding of human genetic variation and clinical manifestations of the disease. In this review, we discuss the genetics of HCM and how to integrate genetic testing in clinical practice.

Download Full-text

Clinical outcomes and programming strategies of implantable cardioverter defibrillator (ICD) devices during childhood in hypertrophic cardiomyopathy: a UK national cohort study

European Heart Journal ◽

10.1093/ehjci/ehaa946.0733 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

G Norrish ◽

H Chubb ◽

E Field ◽

K McCleod ◽

J Till ◽

...

Keyword(s):

Hypertrophic Cardiomyopathy ◽

Incidence Rate ◽

Clinical Outcomes ◽

P Value ◽

Funding Source ◽

Complication Rates ◽

Antitachycardia Pacing ◽

Icd Implantation ◽

National Cohort ◽

Icd Shock

Abstract Background Sudden cardiac death (SCD) is the most common mode of death in childhood hypertrophic cardiomyopathy (HCM). ICDs have been shown to be effective at terminating malignant ventricular arrhythmias but at the expense of a high incidence of complications. The optimal device and programming strategies to reduce complications in this patient group are unknown. Purpose To describe the programming strategies and clinical outcomes of ICD implantation in childhood HCM. Methods Anonymised, non-invasive clinical data were collected from a retrospective, longitudinal multi-centre cohort of children (<16 years) with HCM (n=687) and an ICD in-situ from the United Kingdom. Results 96 patients (61 male (64%), 6 non-sarcomeric (6%)) underwent ICD implantation at a median age 14yr (IQR 11–16, range 3–16) and weight 52.3 kg (IQR 34.8–63.1). Indication for ICD was primary prevention in 72 (75%). 82 (85%) had an endovascular system, 3 (3%) epicardial and 11 (12%) subcutaneous system. 61 patients (74%) were receiving one or more cardioactive medications at implantation [B blockers n=66, 70%, disopyramide n=14, 15%, amiodarone n=7, 7%, calcium channel blocker n=7, 9%, other n=5, 6%]. Programming practices varied: all had VF therapies activated (median 220bpm, IQR 212–230); 70 (73%) had a VT zone programmed (median rate 187 bpm, SD 20.9), of which 26 (27%) had therapies activated. 50 patients (61%) had antitachycardia pacing (ATP) activated. Over a median follow up of 53.6 months (IQR 27.3,108.4), 4 patients (4.2%) died following arrhythmic events despite a functioning device. 25 patients had 53 appropriate therapies (ICD shock n=47, ATP n=8), incidence rate 5.22 (95% CI 3.5–7.8). On univariable analysis, secondary prevention indication for ICD implantation was the only predictor of therapy [16 (64%) vs 8 (11.3%), p value <0.001]. 8 (8.3%) patients had 9 inappropriate therapies (ICD shock n=4, ATP n=5), incidence rate 1.37 (95% CI 0.65–2.8), caused by T wave oversensing (n=2), lead migration (n=1), supraventricular tachycardia (n=1). Device complications were seen in 30 patients (31%), including lead complications (n=16) and infection (n=10). No clinical characteristics predicted time to inappropriate therapy or lead complication. Conclusions In a contemporary cohort of children with HCM, the incidence of inappropriate therapies is lower than previously reported, yet complication rates remain higher than reported in adult patients. No clinical, device or programming strategies were associated with inappropriate therapies or lead complications. Funding Acknowledgement Type of funding source: Other. Main funding source(s): British Heart Foundation

Download Full-text

Hypertrophic cardiomyopathy: prevention of sudden cardiac death

10.1093/med/9780198784906.003.0354 ◽

2018 ◽

Author(s):

Constantinos O’Mahony

Keyword(s):

Hypertrophic Cardiomyopathy ◽

Sudden Cardiac Death ◽

Risk Stratification ◽

Cardiac Death ◽

Clinical Care ◽

Psychological Impact ◽

Ventricular Outflow Tract ◽

Left Ventricular ◽

Icd Implantation ◽

European Society Of Cardiology

Sudden cardiac death (SCD) secondary to ventricular arrhythmias is the most common mode of death in hypertrophic cardiomyopathy (HCM) and can be effectively prevented with an implantable cardioverter defibrillator (ICD). The risk of SCD in HCM relates to the severity of the phenotype and regular risk stratification is an integral part of routine clinical care. For the primary prevention of SCD, risk stratification involves the assessment of seven readily available clinical parameters (age, maximal left ventricular wall thickness, left atrial diameter, left ventricular outflow tract gradient, non-sustained ventricular tachycardia, unexplained syncope, and family history of SCD) which are used to estimate the risk of SCD within 5 years of clinical evaluation using a statistical risk prediction model (HCM Risk-SCD). The 2014 European Society of Cardiology Guidelines provide a framework to aid clinical decisions and consider patients with a 5-year risk of SCD of less than 4% as low risk and recommend regular assessment while those with a risk of 6% or higher should be considered for an ICD. In patients with an intermediate risk (4% to <6%) ICD implantation may also be considered after taking into account age, co-morbid conditions, socioeconomic factors, and the psychological impact of therapy. Survivors of ventricular fibrillation arrest should receive an ICD for secondary prevention unless their life expectancy is less than 1 year. Following device implantation, patients should be followed up for device- and disease-related complications, particularly heart failure and cerebrovascular disease.

Download Full-text