Q-waves associated with postinfarct chronic total occlusion arteries predict non-viable myocardium even in the presence of collaterals

Background and Aim. The presence of grade 3 collaterals is known to be associated with viability in the presence of a chronic total occlusion (CTO). However, it is not clear whether this holds true even in patients who had ST-segment elevation myocardial infarction (STEMI). The aim of our study was to look at the viability of myocardium in patients with CTOs in both infarct-related and non-infarct related occluded vessels with grade 3 collaterals. Methods. We prospectively collected consecutive patients with CTOs who had good grade 3 collaterals and studied the viability of the myocardium in the segment perfused by these occluded arteries. Viability was assessed with a positron emission tomography (PET) scan with fluoro-deoxyglucose uptake. Results. A total of 75 patients (60 men and 15 women; age, 61 ± 9 years) were included in the study; of these, 25 patients had a previous MI with Q-waves on the electrocardiogram. All 25 patients (100%) with a previous MI had non-viable myocardium, while those without a history of previous MI had viable myocardium on the PET scan. The overall left ventricular function or regional wall-motion abnormality did not have an influence on the viability. Conclusion. In the presence of previous STEMI, if the infarct-related artery is a CTO, the myocardium supplied by that vessel is most likely non-viable even in the presence of grade 3 collaterals.