Frequency of myocardial infarction and its relationship to angiographic collateral flow in territories supplied by...

Area of Science:

• Cardiology
• Radiology
• Cardiovascular Imaging

Background:

• Myocardial infarction (MI) diagnosis is challenging in chronic total occlusion (CTO) due to interrupted coronary flow.
• Cardiac MRI is crucial for evaluating MI extent and impact in CTO patients.
• Assessing collateral flow is key to understanding myocardial injury in CTO.

Purpose of the Study:

• To determine the frequency and extent of myocardial infarction in CTO patients.
• To evaluate the relationship between MI, regional systolic function, and collateral flow.
• To improve diagnostic strategies for MI in the context of CTO.

Main Methods:

• 170 patients with angiographically documented CTO were included.
• Cardiac MRI assessed regional late gadolinium enhancement and wall motion abnormalities.
• Angiographic collateral flow was quantified using collateral connection grade and Rentrop score.

Main Results:

• 86% of patients showed evidence of MI by late gadolinium enhancement on cardiac MRI.
• Increased collateral flow correlated with reduced Q waves on ECG (25% prevalence).
• Higher collateral flow was associated with better regional systolic function and less myocardial scarring (P<0.001).

Conclusions:

• Myocardial infarction is significantly more frequent in CTO territories than previously recognized.
• The extent of myocardial injury in CTO is inversely related to the degree of angiographic collateral flow.
• Cardiac MRI and collateral assessment are vital for managing CTO-related myocardial injury.