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Updated: Apr 12, 2026
In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography
Published on: February 16, 2016
Combined analysis of myocardial function, viability, and stress perfusion in patients with chronic total occlusion in
Łukasz A Małek1, Mateusz Śpiewak, Mariusz Kłopotowski
1Department of Interventional Cardiology and Angiology, Institute of Cardiology, Warsaw, Poland. lmalek@ikard.pl.
Insights
Well-developed collateral circulation in chronic total occlusion (CTO) is linked to better heart muscle function and less damage. Cardiovascular magnetic resonance (CMR) can assess this for revascularisation decisions.
Area of Science:
- Cardiovascular Medicine
- Interventional Cardiology
- Diagnostic Imaging
Background:
- Revascularisation decisions for coronary artery chronic total occlusion (CTO) depend on myocardial function, viability, and ischemia.
- Collateral flow to the occluded artery is crucial for the technical success of revascularisation procedures.
Purpose of the Study:
- To evaluate the relationship between the extent of collateral blood flow and the characteristics of the myocardium supplied by the occluded artery.
- To determine if well-developed collateral circulation impacts myocardial function and viability in CTO patients.
Main Methods:
- 54 patients with CTO undergoing cardiovascular magnetic resonance (CMR) for revascularisation assessment were studied.
- Well-developed collateral flow was defined using collateral connection grade = 2 and Rentrop score = 3.
- CMR was used to assess myocardial function, viability, and perfusion deficits.
Main Results:
- Patients with well-developed collaterals (44%) showed less systolic dysfunction in the supplied segments (p=0.04).
- They had lower rates of previous myocardial infarction (38% vs. 67%, p=0.03) but similar transmural infarction rates (p=0.83).
- Fewer perfusion deficits during hyperemia (42% vs. 70%, p=0.03) and smaller deficit sizes (p=0.04) were observed in patients with good collaterals.
Conclusions:
- Myocardium supplied by CTO with good collaterals exhibits reduced inducible ischemia, preserved systolic function, and lower infarction risk.
- Cardiovascular magnetic resonance (CMR) is a valuable non-invasive tool for evaluating CTO patients considered for revascularisation.
Background:
Indications for revascularisation in chronic total occlusion (CTO) of the coronary artery depend on the interplay between myocardial function, viability, and ischaemia. The technical feasibility of the procedure often relies on the collateral flow to the occluded artery.
Aim:
To assess the relation between the degree of collateral flow and characteristics of the myocardium supplied by the oc-cluded artery.
Methods:
The study included 54 patients (mean age 62 years, 85% males) with CTO referred for cardiovascular magnetic resonance (CMR) to assess indications for revascularisation. The presence of well-developed collateral flow was defined as a collateral connection grade = 2 and Rentrop score = 3.
Results:
The presence of well-developed collaterals (n = 24, 44%) was less likely to be related to systolic dysfunction of the segments supplied by the occluded artery (mean wall motion score index 1.31 ± 0.44 vs. 1.64 ± 0.67, p = 0.04) in comparison to a lack of well-developed collaterals. Patients with well-developed collaterals had a lower frequency of previous myocar-dial infarction of the CTO territory (38% vs. 67%, p = 0.03) with similar frequency of transmural infarctions (21% vs. 23%, p = 0.83). They less frequently presented perfusion deficits of the CTO area during hyperaemia (42% vs. 70%, p = 0.03) and the size of deficits was smaller (median 0.0% [interquartile range 0-12%] vs. 7.5% [0-15%], p = 0.04).
Conclusions:
Myocardial segments supplied by CTO with well-developed collaterals are less prone to inducible ischaemia, have better systolic function, and are less likely to undergo myocardial infarction, in comparison to those supplied by CTO with poor collateral circulation. CMR is a non-invasive method that can be used for a comprehensive workup of patients be-ing considered for CTO revascularisation.
