Effects of Cardiac Stem Cell on Postinfarction Arrhythmogenic Substrate

Area of Science:

• Regenerative Medicine
• Cardiovascular Research
• Cell Therapy

Background:

• Clinical observations suggest cardiosphere-derived cells (CDCs) may improve cardiac remodeling and reduce ventricular tachycardia (VT) post-myocardial infarction (MI).
• The precise mechanisms by which CDCs affect the VT substrate, particularly scar tissue, require further investigation.

Purpose of the Study:

• To evaluate the impact of CDCs on the electrophysiological and histological properties of the post-infarction VT substrate in a porcine model.
• To determine if CDC treatment can reduce the inducibility and complexity of VT in this model.

Main Methods:

• A porcine model of monomorphic VT was established via LAD artery occlusion.
• Pigs received either intracoronary plus trans-myocardial CDCs (IC+TM group) or served as controls, 4 weeks post-MI.
• Electrophysiological assessment using optical mapping and histological analysis were performed 16 weeks post-MI.

Main Results:

• CDCs treatment led to increased conduction velocity and action potential duration (APD) in heterogeneous tissue (HT), while decreasing APD dispersion.
• VT inducibility was significantly lower in the CDC-treated group (1/10) compared to controls (7/10).
• Histological analysis revealed reduced fibrosis and myofibroblast density, with increased connexin-43 expression in the HT of CDC-treated hearts.

Conclusions:

• Allogeneic CDCs administered early after MI can effectively modify the electrophysiological and structural characteristics of the post-infarction scar.
• These modifications suggest a novel therapeutic potential for CDCs in managing VT and improving cardiac repair after MI.