Ischemia modulation via coronary revascularization and effects on the arrhythmic substrate

Area of Science:

• Cardiology
• Electrophysiology
• Cardiac Imaging

Background:

• Ischemic left ventricular dysfunction (ILVD) often requires coronary revascularization to alleviate ischemia.
• The impact of revascularization on the substrate for ventricular arrhythmias in ILVD remains unclear.

Purpose of the Study:

• To evaluate how revascularization affects arrhythmic substrate in ILVD.
• To determine the relationship between changes in arrhythmic substrate, ischemia, and myocardial scar.

Main Methods:

• Patients with LVEF ≤40% and extensive coronary disease underwent PCI or CABG.
• Stress-perfusion cardiac magnetic resonance (pCMR) assessed scar and ischemic burden.
• Non-invasive electrocardiographic imaging (ECGi) evaluated arrhythmic substrate using LV activation recovery interval (ARI).

Main Results:

• Revascularization improved LVEF and reduced ischemic burden, but scar burden remained unchanged.
• Mean LV ARI dispersion did not change significantly post-revascularization.
• Individual changes in LV ARI dispersion correlated with changes in ischemic burden.

Conclusions:

• Arrhythmic substrate in ILVD patients was linked to scar burden and not altered by revascularization.
• Residual ischemia after revascularization correlated with residual arrhythmic substrate.
• Personalized risk stratification considering ischemia reduction and arrhythmic risk is necessary.