Hyper-synchronicity in Hypertrophic Cardiomyopathy (HCM) : Description, Mechanism and Origin With a Multi-imaging Approach to Predict Dual Chamber Pacing Response (HSYNC)

Identification and Quantification of a Mechanical Hyper-synchronicity State in Hypertrophic Cardiomyopathy (HCM) With Left Outflow-tract Obstruction and Description of Its Electrical and Electro-mechanical Characteristics Thanks to an Innovative Multi-imaging Approach to Predict a Positive Response to Dual Chamber Pacing. The Hsync Study.

Hypertrophic cardiomyopathy (HCM) is a common genetic cardiovascular disease. Outflow-tract gradient of 30 mmHg or more under resting conditions is an independent determinant of symptoms of progressive heart failure and death.

The investigators hypothesize that the electrical approach by dual chamber pacing could improve symptoms and reduce outflow-tract obstruction in a specific sub-group of selected patients with a mechanical hyper-synchronicity. The aim of the study is to identify and describe this phenomenon in HCM with (O-HCM) and without (NO-HCM) outflow-tract obstruction thanks to innovative multi-imaging approach.

Study Overview

• Status: Completed
• Conditions: Hypertrophic Cardiomyopathy; Mechanical Hyper-synchronicity
• Intervention / Treatment: Procedure: Echocardiography (TEE); Device: Magnetic resonance imaging (MRI) with gadolinium enhancement; Procedure: 3D electrocardiographic mapping (ECM); Device: Magnetic resonance imaging (MRI) without gadolinium enhancement

Detailed Description

The concept of physiological ventricular desynchrony was described recently with technics of myocardial deformation analysis applied in animal models. Authors confirmed the existence of a time delay in the contraction of the apical walls before basal walls. In O-HCM, the outflow-tract obstruction could be explained by a mechanical hyper-synchronicity between apical and basal walls. This study aims to describe the possible hyper-synchronized contraction in O-HCM and NO-HCM patients unlike the physiological desynchrony observed in healthy volunteers (HV) For this purpose, three imaging tests will be used at baseline: echocardiography (TEE), magnetic resonance imaging (MRI) with gadolinium enhancement only in HCM, and 3-dimensional electrocardiographic mapping (ECM) combined with computed tomography-scan. No follow-up is planned for this study.

• Study Type: Interventional
• Enrollment (Actual): 60
• Phase: Not Applicable

Contacts and Locations

Study Locations

• France
  • Bordeaux, France, 33000
    • CHU de Bordeaux

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• HCM: Adults aged more than 18 years with sarcomeric hypertrophic cardiomyopathy under optimal medical therapy, isolated septal hypertrophy, sinus rhythm, exploitable acoustic window. For women of childbearing age, effective contraception and required negative pregnancy test.
• O-HCM : outflow-tract gradient more than 30 mmHg at rest and during exercise
• NO-HCM : outflow-tract gradient less than 30 mmHg at rest and during exercise
• HV: Adults aged more than 18 years, without cardiovascular disease. For women of childbearing age, effective contraception and required negative pregnancy test.

Exclusion Criteria:

- HV: unusable acoustic window

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: O-HCM; 20 patients with Hypertrophic Cardiomyopathy with outflow-tract obstruction	Procedure: Echocardiography (TEE); Device: Magnetic resonance imaging (MRI) with gadolinium enhancement; Procedure: 3D electrocardiographic mapping (ECM); Other Names: 3-dimensional electrocardiographic mapping (ECM) combined with computed tomography-scan
Experimental: NO-HCM; 20 patients with Hypertrophic Cardiomyopathy without outflow-tract obstruction	Procedure: Echocardiography (TEE); Device: Magnetic resonance imaging (MRI) with gadolinium enhancement; Procedure: 3D electrocardiographic mapping (ECM); Other Names: 3-dimensional electrocardiographic mapping (ECM) combined with computed tomography-scan
Other: healthy volunteers; 20 healthy volunteers	Procedure: Echocardiography (TEE); Procedure: 3D electrocardiographic mapping (ECM); Other Names: 3-dimensional electrocardiographic mapping (ECM) combined with computed tomography-scan; Device: Magnetic resonance imaging (MRI) without gadolinium enhancement

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mechanical time delay in contraction between basal and apical walls in TEE and MRI in O-HCM, NO-HCM and healthy volunteers	The main interest variable is the delay value (ms) of the contraction between basal and apical walls measured by TEE and MRI.	Day 1

Secondary Outcome Measures

Outcome Measure	Time Frame
Relationship between each mesure with hyper-synchronicity and outflow-tract gradient	Day 1
Electrical time delay in ECM between basal and apical walls and relationship with hyper-synchronicity and outflow tract gradient.	Day 1
Mechanical time delay between septal and lateral walls in MRI and TEE.	Day 1
Evolution of mechanical time delay between basal and apical walls at rest and exercise in O-HCM and NO-HCM and relationship with outflow-tract gradient.	Day 1
Delay between peaks of basal and apical radial displacement in MRI	Day 1
Delay between the beginning of the apical and basal radial displacement in MRI	Day 1
Apical-basal phase on a phase analysis of the radial displacement data in MRI	Day 1
Delay between apical and basal peaks circumferential strain in MRI	Day 1
Delay between the beginning of the apical and basal circumferential deformation in MRI	Day 1
Twist angle between the base and the apex in MRI	Day 1

Collaborators and Investigators

• Sponsor: University Hospital, Bordeaux
• Investigators: Principal Investigator: Claire CORNOLLE, Dr, University Hospital, Bordeaux

Study record dates

Study Major Dates

• Study Start (Actual): June 22, 2015
• Primary Completion (Actual): January 19, 2019
• Study Completion (Actual): January 19, 2019

Study Registration Dates

• First Submitted: June 26, 2015
• First Submitted That Met QC Criteria: September 23, 2015
• First Posted (Estimate): September 24, 2015

Study Record Updates

• Last Update Posted (Actual): February 14, 2022
• Last Update Submitted That Met QC Criteria: February 8, 2022
• Last Verified: February 1, 2022

More Information

Terms related to this study

• Keywords: Hypertrophic cardiomyopathy, hyper-synchronicity, outflow-tract obstruction, dual chamber pacing
• Additional Relevant MeSH Terms: Heart Diseases; Cardiovascular Diseases; Pathological Conditions, Anatomical; Aortic Valve Disease; Heart Valve Diseases; Aortic Stenosis, Subvalvular; Aortic Valve Stenosis; Hypertrophy; Cardiomyopathies; Cardiomyopathy, Hypertrophic
• Other Study ID Numbers: CHUBX 2014/06