Clinical Outcomes of PIMSRA Treating for Hypertrophic Obstructive Cardiomyopathy: A Large-Sample Study

Clinical Outcomes of Percutaneous Intramyocardial Septal Radiofrequency Ablation Treating for Hypertrophic Obstructive Cardiomyopathy: A Large-Sample Study

The Hypertrophic Cardiomyopathy Center of Xijing Hospital pioneered percutaneous intramyocardial septal radiofrequency ablation (PIMSRA) as an innovative treatment for hypertrophic obstructive cardiomyopathy (HOCM) to relieve left ventricular outflow tract obstruction. Clinical studies have confirmed PIMSRA's efficacy, safety and reliability, establishing it as a novel alternative for septal reduction therapy. As a novel interventional approach, comprehensive evaluation of its safety and therapeutic effectiveness is warranted.

Therefore, this retrospective study aims to:

• Investigate postoperative clinical outcomes and their influencing factors in HOCM patients undergoing PIMSRA;
• Analyze morphological and hemodynamic changes including: septal thickness, left ventricular outflow tract gradient, mid-ventricular pressure gradient and left ventricular flow field dynamics;
• Examine correlations between clinical/procedural parameters and clinical symptoms, quality of life and cardiac reverse remodeling indicators.

This study will provide high-quality evidence to support the clinical application of this novel procedure.

Study Overview

• Status: Active, not recruiting
• Conditions: Hypertrophic Obstructive Cardiomyopathy (HOCM)
• Intervention / Treatment: Procedure: Percutaneous Intramyocardial Septal Radiofrequency Ablation

• Study Type: Observational
• Enrollment (Estimated): 800

Contacts and Locations

Study Locations

• China
  • Shaanxi
    • Xi'an, Shaanxi, China, 710032
      • Ultrasound Medicine Department of Xijing Hospital, Fourth Military Medical University

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

Patients who are diagnosed with HOCM and with drug-refractory symptoms underwent PIMSRA in Xijing Hospital from 2016 to 2025.

Description

Inclusion Criteria:

• All HOCM patients who underwent PIMSRA treatment, including those with left ventricular outflow tract and middle ventricular obstruction;
• Age from 18 to 90 years old.

Exclusion Criteria:

• Patients lost to follow-up whose follow-up period did not reach 6 months;
• Incomplete clinical data affected statistical analysis.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Hypertrophic Obstructive Cardiomyopathy Patients Underwent PIMSRA

Procedure: Percutaneous Intramyocardial Septal Radiofrequency Ablation; With the real-time guidance of TTE, a radiofrequency electrode needle was percutaneously inserted via the transapical intramyocardial approach into the hypertrophied septum for thermal ablation. Intraoperative TTE and 12-lead electrocardiographic monitoring were employed to assess the ablation extent and prevent vascular and cardiac conduction bundle injury. The success of ablation was confirmed by evaluating contrast medium perfusion defects in the ablated areas and comparing them with the preprocedural hypertrophied septum.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Major adverse cardiovascular events	Major adverse cardiovascular events including but not limited to: All-cause death;; Arrhythmic events: resuscitated cardiac arrest or ventricular tachycardia/fibrillation, appropriate implantable cardioverter-defibrillator discharge, atrioventricular block, pacemaker implantation and atrial fibrillation;; Acute heart failure: acute pulmonary edema, new-onset NYHA class Ⅲ-IV symptoms, and heart failure-related hospitalization;; Cardiogenic shock: cardiac disorder that results in a systolic blood pressure <90 mmHg for ≥30 min (or the need for vasopressors, inotropes or mechanical circulatory support to maintain systolic blood pressure ≥90 mmHg) with evidence of hypoperfusion;; Severe systolic anterior motion: the proximal portion of the anterior mitral leaflet moved excessively close to the septum, resulting in extreme LVOT obstruction and acute haemodynamic collapse;; Cerebrovascular events: all stroke (ischemic or hemorrhagic) and transient ischemic attacks.	Observations were conducted from the immediate postoperative period through 1-year follow-up, with assessment time points including but not limited to 1 month, 3 months, 6 months, and 1 year.
Procedure-related adverse events	Any instrument or procedure-related complications, including but not limited to death, emergency surgery, pericardial tamponade requiring pericardiocentesis or surgery, bleeding, procedure-related stroke.	Observations were conducted from the immediate postoperative period through 1-year follow-up, with assessment time points including but not limited to 1 month, 3 months, 6 months, and 1 year.
Interventricular septal thickness	Maximum septal thickness as measured by echocardiography.	Observations were conducted from the immediate postoperative period through 1-year follow-up, with assessment time points including but not limited to 1 month, 3 months, 6 months, and 1 year.
Left ventricular outflow tract gradient	Left ventricular outflow tract gradient as measured by echocardiography.	Observations were conducted from the immediate postoperative period through 1-year follow-up, with assessment time points including but not limited to 1 month, 3 months, 6 months, and 1 year.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
New York Heart Association Classification	The New York Heart Association Classification involved 4 classes. I-No limitation of physical activity, II-Slight limitation of physical activity, III-Marked limitation of physical activity, IV-Unable to carry on any physical activity without discomfort. A higher grade means worse heart function.	Observations were conducted from the immediate postoperative period through 1-year follow-up, with assessment time points including but not limited to 1 month, 3 months, 6 months, and 1 year.
Kansas City Cardiomyopathy Questionnaire score	The Kansas City Cardiomyopathy Questionnaire was a 23-item, self-administered questionnaire that measure the participant's perception of their health status. It quantifies 7 domains: physical limitations (6 items), symptom stability (1 item), symptom frequency (4 items), symptom burden (3 items), self-efficacy (2 items), quality of life (3 items) and social limitations (4 items). Scores were generated from each domain and scaled from 0 to 100, where lower scores represent more severe symptoms and/or limitations and scores of 100 indicate no symptoms, no limitations, and excellent quality of life.	Observations were conducted from the immediate postoperative period through 1-year follow-up, with assessment time points including but not limited to 1 month, 3 months, 6 months, and 1 year.
Late gadolinium enhancement	Late gadolinium enhancement measured by cardiac magnetic resonance.	Observations were conducted from the immediate postoperative period through 1-year follow-up, with assessment time points including but not limited to 1 month, 3 months, 6 months, and 1 year.
Mean blood pressure	Mean systolic/diastolic blood pressure measured by ambulatory blood pressure monitoring.	Observations were conducted from the immediate postoperative period through 1-year follow-up, with assessment time points including but not limited to 1 month, 3 months, 6 months, and 1 year.
Energy loss	Energy loss measured by vector flow mapping.	Observations were conducted from the immediate postoperative period through 1-year follow-up, with assessment time points including but not limited to 1 month, 3 months, 6 months, and 1 year.

Collaborators and Investigators

• Sponsor: Xijing Hospital

Study record dates

Study Major Dates

• Study Start (Actual): April 29, 2025
• Primary Completion (Estimated): June 30, 2027
• Study Completion (Estimated): June 30, 2027

Study Registration Dates

• First Submitted: April 30, 2025
• First Submitted That Met QC Criteria: May 26, 2025
• First Posted (Actual): June 4, 2025

Study Record Updates

• Last Update Posted (Actual): June 4, 2025
• Last Update Submitted That Met QC Criteria: May 26, 2025
• Last Verified: April 1, 2025

More Information

Terms related to this study

• Keywords: safety; efficacy; Treatment outcome; Cardiomyopathy, hypertrophic; Percutaneous intramyocardial septal radiofrequency ablation
• Additional Relevant MeSH Terms: Aortic Valve Disease; Cardiovascular Diseases; Pathological Conditions, Anatomical; Heart Diseases; Heart Valve Diseases; Aortic Stenosis, Subvalvular; Aortic Valve Stenosis; Cardiomyopathies; Cardiomyopathy, Hypertrophic; Hypertrophy
• Other Study ID Numbers: KY20242272-C-1

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