Optimisation of Decision Making for Defibrillator Implantation in Hypertrophic Cardiomyopathy

Study Overview
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Brief Summary
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The main objective of the study is to improve implantable cardioverter defibrillator (ICD) implantation decision-making processing relevance by developing a new prediction model of sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM), including newly identified potential biomarkers by magnetic resonance imaging (MRI) and genetics, through a prospective nationwide study, multivariate analysis and modelling of an absolute risk. The secondary objective is to perform a medico-economic analysis of ICD implantation in order to define an optimal rule for ICD implantation in patients with HCM, taking into account the benefits of ICD, adverse effects of ICD and associated costs (cost of quality adjusted life years saved).

Detailed Description
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HCM is a genetic disease, usually autosomal dominant, with a prevalence of about 1/500 in the general population. HCM represents a major cause of SCD in the young, and is the first cause of SCD in athletes less than 35 years of age. The only efficient prevention of SCD, apart from exercise restriction, is ICD. Given this dreadful potential outcome of HCM, the identification of patients that should receive an ICD is of paramount importance. However, the indications for ICD are controversial and very different guidelines are currently available, coming from the American society of Cardiology, the French Haute Autorité de Santé and from the European society of Cardiology. In addition, these guidelines are all based on retrospective studies and have major limitations. The situation faces a critical need of improvement. Thus, this study has been designed with the objective to propose a revision of international recommendations for defibrillator implantation in HCM patients. This prospective multicenter non-interventional single-arm study is planned to be conducted in 40 sites with a collection of clinical and biological data, carried out as required for the usual management and care of patients. No investigation will be performed specifically for this study except for an additional blood sample collection at baseline during routine outpatient care and annual interview during follow-up.

Official Title
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Optimisation of Decision Making for Defibrillator Implantation in Hypertrophic Cardiomyopathy

Conditions
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Hypertrophic Cardiomyopathy

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patient with a diagnosis of HCM based on conventional criteria (left ventricle wall thickness ≥ 15 mm in adult index or ≥ 13 mm in adult relatives) in the absence of abnormal loading conditions Aged ≥ 16 years Patient without or with a defibrillator (in this latter case it should have been implanted for primary prevention, not for secondary prevention) Affiliation to a social security insurance Exclusion Criteria: Specific etiologies such as amyloidosis Patients with ICD as secondary prevention (after aborted SCD or sustained ventricular arrhythmia)

Ages Eligible for Study
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Minimum Age: 16 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Improvement of the ability to predict major clinical events: C-index comparisons | Comparisons of the C-index obtained between with the new score and with the different existing scores or algorithms of actual processing used for ICD decision-making. C-index is a discrimination index, which will be determined after multivariate analyses and score modeling, in the case of the new score. This evaluate of the improvement of the ability to predict major clinical events during follow-up will toward to development of a new prediction model in patients with HCM in responding the main objective of the study. Data will be collected are: (composite end point): SCD, aborted sudden death, appropriate therapy of ICD that is a physiological equivalent of SCD. | throughout of the study, an average of 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cost-effectiveness study | To determine incremental cost-effectiveness ratio (ICER) of ICD decision, in order to assess the economic impact of defibrillator implantation as a function of the chosen rule for device implantation. Data will be collected are: direct costs (health insurance tariffs) of defibrillators, cost of their maintenance and for management of side effects, for the treatment of sudden death recovered, the medical transport, hospitalizations and for cardiology acts. | throughout of the study, an average of 1 year | 
| Cost-utility analysis | To determine incremental cost-utility ratio of ICD decision, in order to assess the economic impact of defibrillator implantation as a function of the chosen rule for device implantation. Data will be collected are: direct costs (health insurance tariffs) of defibrillators, cost of their maintenance and for management of side effects, for the treatment of sudden death recovered, the medical transport, hospitalizations and for cardiology acts. | throughout of the study, an average of 1 year | 
| Quality Adjusted Life Years | QALYs calculated using EQ-5d Index: EQ5D-5L QoL questionnaire, a questionnaire established by EuroQol Group in 5 dimensions with 5 levers. | at baseline and at 6-year follow-up | 
| Improvement of the ability to predict major clinical events: C-index comparisons | Comparison of the C-index obtained between the new score developed for the primary objective and the C-index obtained when the following additional covariates are added to the multivariate predictive model: gender, maximum left ventricle wall thickness obtained by MRI, left atrial volume on echocardiography, left ventricle strain on echocardiography. | at baseline | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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hypertrophic cardiomyopathy, implantable cardioverter defibrillator