Nonobstructive Hypertrophic Cardiomyopathy
Conditions
Keywords
Nonobstructive Hypertrophic Cardiomyopathy, Septal Myectomy, Mitral Regurgitation, Transapical, Off-pump, Minimally invasive
Brief summary
The primary purpose of this study is to evaluate the feasibility, the safety and the efficacy of the transapical beating-heart septal myectomy for the treatment of nonobstructive hypertrophic cardiomyopathy. This is a prospective, single-arm, single-center study.
Detailed description
Medical therapy is first recommended for patients with nonobstructive hypertrophic cardiomyopathy administrated at onset of heart failure symptoms. As the disease progresses, patients with global ejection fraction \< 50% should be evaluated with respect to eligibility and motivation for heart transplant. However, for those with preserved ejection fraction and drug-refractory heart failure symptoms, there is still no optimal therapy. Some patients with increased left atrial volume and/or diastolic dysfunction can be recognized as a result of excessive myocardial hypertrophy, and the septal resection for these patients may be beneficial. However, conventional septal myectomy is hindered by the demanding expertise that is needed to sufficient resection of hypertrophied septal myocardium while guarantee safety. To increase the visualization and minimize the surgical injury of conventional septal myectomy, we have invented a novel beating-heart myectomy device. Through a mini-thoractomy, septal myectomy could be accomplished via a transapical access in the beating heart using the beating-heart myectomy device. The whole process of resection is monitored, navigated, and evaluated by real-time transesophageal and transthoracic echocardiography. Left ventricular morphology and hemodynamics are evaluated each time after resection. Multiple resections are performed to tailor sufficient enlargement of left ventricular end-diastolic volume and improvement of mitral regurgitation, while preventing iatrogenic injuries. After transapical beating-heart septal myectomy, patients are scheduled to be seen for follow-up visits at discharge (about 7 days post operation) and 3 months.
Interventions
We have invented a beating-heart myectomy device.Through a minimally invasive intercostal incision, septal myectomy could be accomplished via a transapical access in the beating heart using the device. The whole process of resection is monitored, navigated, and evaluated by real-time transesophageal and transthoracic echocardiography. Left ventricular end-diastolic volume and the grade of mitral regurgitation are evaluated each time after resection. Multiple resections are performed to tailor the muscular resection for sufficient enlargement of left ventricular end-diastolic volume and improvement of mitral regurgitation, while preventing iatrogenic injuries.
Sponsors
Xiang Wei
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Intervention model description
Experimental Group: Beating-heart myectomy device
Eligibility
Sex/Gender
ALL
Age
8 Years to 80 Years
Healthy volunteers
No
Inclusion criteria
1. Patients whose maximal ventricular septal wall thickness ≥ 15 mm. 2. Patients with heart function of New York Heart Association ≥ class II. 3. Patients with drug-refractory symptoms or intolerable to pharmaceutical therapies. 4. Patients who was informed the nature of the clinical trial, consented to participate in all of the activities of the clinical trial, and signed the informed consent form
Exclusion criteria
1. Patients who were pregnant. 2. Patients who had concomitant diseases such as intrinsic valvular disease or coronary artery disease that needed open-heart surgery. 3. Patients who had severe heart failure with left ventricle ejection fraction \< 40%. 4. Patients whose estimated life expectancy \< 12 m. 5. Patient who were non-compliant. 6. Patients under circumstances which were considered not suitable or prohibitive for participating the clinical trial at the discretion of the attending medical team and the researchers.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| All-cause mortality | 3 months | Death from any cause during the observation period. |
| Procedural success | 3 months | A reduction of ≥1 New York Heart Association (NYHA) class and a decrease of ≥ 20% of left atrial volume |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Left ventricle mass | 7 days and 3 months | Left ventricle mass index (the ratio of left ventricle mass to body weight) as measured by cardiac magnetic resonance. |
| Left atrial volume | 7 days and 3 months | The left atria volume as measured by echocardiography. |
| Major adverse cardiovascular and cerebral events | 3 months | In-hospital mortality, atrioventricular block that need permanent pacemaker implantation, sternotomy conversion, iatrogenic ventricular septal perforation, iatrogenic valvular injury, imaging examination-validated cerebral complications. |
| New York Heart Association class | 7 days and 3 months | New York Heart Association class, including grade I, grade II, grade III, grade IV. A higher grade means worse heart function. |
| Device success | 1 day | Successful accession, delivery, and retrieval of the resection device, successful resection of the septal myocardium, mitral regurgitation (MR) ≤ grade 2+ during operation after resection, and free from conversion to midline thoracotomy during operation. |
| Heart function-associated quality of life | 7 days and 3 months | Score of the Kansas City Cardiomyopathy Questionnaire. A higher score means better heart function. |
| Evaluation of the mitral valve | 7 days and 3 months | Grade of mitral regurgitation and systolic anterior motion as measured by echocardiography. |
| Left ventricular outflow tract diameter | 7 days and 3 months | Left ventricular outflow tract diameter as measured by echocardiography. |
| Left ventricular end-diastolic volume | 3 months | Left ventricular end-diastolic volume as measured by cardiac magnetic resonance. |
| 6-minute walking test | 3 months | 6-minute walking test. A longer distance means better heart function. |
| Septal thickness | 7 days and 3 months | Basal and mid septal thickness as measured by echocardiography. |
Countries
China
Contacts
Primary ContactXiang Wei, M.D.
Backup ContactJing Fang, M.D.
Outcome results
None listed