Percutaneous Intramyocardial Septal Radiofrequency Ablation for Obstructive Hypertrophic Cardiomyopathy in Children

Percutaneous Intramyocardial Septal Radiofrequency Ablation for Drug-refractory Obstructive Hypertrophic Cardiomyopathy in Children and Adolescents: An Early Feasibility Study

The primary purpose of this study was to demonstrate the safety and efficacy of percutaneous intramyocardial septal radiofrequency ablation (PIMSRA) in children and assessed its performance and functional outcomes in the follow-up. This is an observational, single-arm, single-center study.

Study Overview

• Status: Completed
• Conditions: Hypertrophic Cardiomyopathy, Obstructive
• Intervention / Treatment: Procedure: Percutaneous intramyocardial septal radiofrequency ablation

Detailed Description

The prevalence of hypertrophic cardiomyopathy (HCM) ranks second among cardiomyopathies in children. The prognosis of HCM has been previously demonstrated to be closely correlated with age. HCM in childhood is frequently associated with severe symptoms and high mortality rates, exhibiting a 36% higher incidence of malignant ventricular arrhythmias compared to adults, and being twice as likely to necessitate advanced heart failure therapies such as heart transplantation or left heart assist devices. Surgical septal myectomy can effectively help patients with drug-refractory symptoms but carries risks inherent to invasive procedures and requires expertise that is not universally available. Alcohol septal ablation is not recommended for applications in the young patient group.

Percutaneous intramyocardial septal radiofrequency ablation (PIMSRA) is a new method for the treatment of HCM using a special diagnosis and treatment device on the target area of the heart under the guidance of echocardiography. The method breaks through the worldwide problem of minimally invasive treatment of the myocardium on the beating heart, thus avoiding X-ray radiation and contrast agent damage. Previous research has illustrated the effectiveness and safety of PIMSRA for adult patients with obstructive HCM. We have found that PIMSRA results in sustained improvement in exercise capacity, persistent reduction in left ventricle outflow tract (LVOT) gradient, and sustained improvement in cardiac function.

This is an early feasibility study to evaluate the clinical safety and efficacy of PIMSRA in pediatric patients, as well as to assess postoperative cardiac function and exercise capacity.

• Study Type: Observational
• Enrollment (Actual): 16

Contacts and Locations

Study Locations

• China
  • Shaanxi
    • Xi'an, Shaanxi, China, 710032
      • Xijing Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

Children with obstructive HCM who remain severely symptomatic despite medical therapy or have LVOT obstruction (peak gradient ≥ 50mmHg) underwent percutaneous intramyocardial septal radiofrequency ablation from September 2020 to December 2023. A total of 16 consecutive children younger than 18 were included.

Description

Inclusion Criteria:

• Clinical diagnosis of hypertrophic obstructive cardiomyopathy
• Age younger than 18 years
• Resting or provoking left ventricular outflow tract gradient ≥ 50 mmHg
• Drug-refractory symptoms or intolerable to pharmaceutical therapies
• Heart function of New York Heart Association ≥ class II

Exclusion Criteria:

• Secondary left ventricular hypertrophy (LVH) related to subaortic stenosis or aortic stenosis
• Presence of concomitant heart disease requiring surgery
• Left ventricular ejection fraction <40%
• Cardiac resynchronization therapy within 3 months

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Safety composite outcome	The number of people who reach the composite safety outcome (the occurrence of at least one) of the following measured variables: 1) all-cause death; 2) heart failure; 3) ventricular fibrillation.	30 days
Feasibility outcome	The proportion of people with a peak left ventricle outflow tract gradient lower than 30 mmHg or decreased by more than 50%.	6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Major surgery-related adverse events	Emergency surgery, severe pericardial tamponade, conduction block due to deviation in ablation range, surgery related ventricular septal perforation, stroke and malignant arrhythmias.	30 days
LVOT gradient	Left ventricular outflow tract gradient as measured by echocardiography.	through study completion, an average of 2 years
Maximum interventricular septal thickness	Maximum septal thickness as measured by echocardiography.	through study completion, an average of 2 years
New York Heart Association functional scale	New York Heart Association class, including grade I, grade II, grade III, grade IV. A higher grade means worse heart function.	through study completion, an average of 2 years

Collaborators and Investigators

• Sponsor: Xijing Hospital
• Investigators: Principal Investigator: Liwen Liu, Ph.D, M.D., Xijing Hospital

Publications and helpful links

General Publications

• Liu L, Li J, Zuo L, Zhang J, Zhou M, Xu B, Hahn RT, Leon MB, Hsi DH, Ge J, Zhou X, Zhang J, Ge S, Xiong L. Percutaneous Intramyocardial Septal Radiofrequency Ablation for Hypertrophic Obstructive Cardiomyopathy. J Am Coll Cardiol. 2018 Oct 16;72(16):1898-1909. doi: 10.1016/j.jacc.2018.07.080.
• Zhou M, Ta S, Hahn RT, Hsi DH, Leon MB, Hu R, Zhang J, Zuo L, Li J, Wang J, Wang B, Zhu X, Liu J, Han Y, Li X, Xu B, Zhang L, Hou L, Han C, Liu J, Liu L. Percutaneous Intramyocardial Septal Radiofrequency Ablation in Patients With Drug-Refractory Hypertrophic Obstructive Cardiomyopathy. JAMA Cardiol. 2022 May 1;7(5):529-538. doi: 10.1001/jamacardio.2022.0259.

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2020
• Primary Completion (Actual): June 1, 2024
• Study Completion (Actual): June 7, 2024

Study Registration Dates

• First Submitted: July 22, 2024
• First Submitted That Met QC Criteria: August 1, 2024
• First Posted (Actual): August 6, 2024

Study Record Updates

• Last Update Posted (Actual): August 6, 2024
• Last Update Submitted That Met QC Criteria: August 1, 2024
• Last Verified: October 1, 2023

More Information

Terms related to this study

• Keywords: children; hypertrophic cardiomyopathy; Percutaneous Intramyocardial Septal Radiofrequency Ablation
• 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: KY20232356

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No