Resident stem cells in the myocardium of patients with obstructive hypertrophic cardiomyopathy

Area of Science:

• Cardiovascular Medicine
• Stem Cell Biology
• Cardiac Pathology

Background:

• Obstructive hypertrophic cardiomyopathy (HCM) is a primary genetic heart muscle disease.
• The role of resident cardiac stem cells in HCM pathogenesis remains unclear.
• Understanding cellular changes in HCM myocardium is crucial for therapeutic development.

Purpose of the Study:

• To investigate the presence and characteristics of c-kit-positive resident cardiac stem cells in the interventricular septum of patients with obstructive HCM.
• To correlate the findings of cardiac stem cells with specific histopathological features and clinical parameters.

Main Methods:

• Studied interventricular septum myocardium from 40 patients with obstructive HCM.
• Utilized immunohistochemical assays to identify c-kit-positive cells.
• Quantified connective tissue content, myofibrillar disarray, cardiomyocyte hypertrophy, and myolysis.
• Assessed atrial natriuretic peptide presence in cardiomyocytes.

Main Results:

• c-kit-positive resident cardiac stem cells were detected in 82.5% of HCM patients.
• Cardiac stem cells were associated with increased connective tissue density.
• Presence of stem cells correlated with cardiomyocyte hypertrophy, moderate myolysis, and atrial natriuretic peptide accumulation.
• Atrial natriuretic peptide, a marker of cardiac failure, was found in 30% of cases.

Conclusions:

• Resident cardiac stem cells are present in the myocardium of patients with obstructive HCM.
• These cells are linked to specific pathological hallmarks of HCM, including fibrosis and cardiomyocyte remodeling.
• The findings suggest a potential role for resident cardiac stem cells in the disease process and progression of HCM.