Abstract
It has been rarely encountered some patients in clinical practice with coronary artery
chronic total occlusion (CTO) on angiography but no any clinical history or electrocardiographic,
echocardiographic, or left ventriculographic evidence of previous myocardial infarction.
These noninfarct-related artery CTO (non-IRA CTO) lesions may be used as a clinical
role model of endogenous cardioprotective mechanisms in addition to continuing the
process of atherosclerosis. The objective of this study was to characterize the clinical
characteristics of patients with non-IRA CTO patients and compared them to those with
infarct-related CTO (IRA-CTO). We reviewed our invasive cardiology database searching
for the CTO of any major coronary arteries, and assessed whether or not they have
the clinical history or electrocardiographic, echocardiographic, and left ventriculographic
evidence of previous myocardial infarction. Interestingly, we detected that all these
patients with non-IRA CTO had diabetes mellitus, and the clinical and demographic
features of these non-IRA CTO patients were compared with age- and sex-matched diabetic
IRA-CTO patients with regard to conventional coronary risk factors and the angiographic
collateral grading system. There were total 99 CTO patients (49 patients with non-IRA
CTO and 50 patients with IRA-CTO).All patients with non-IRA CTO had better collateral
circulation (96 vs. 40% p < 0.001) compared with those having IRA-CTO. The only significant difference between
the groups was the status of current smoking (4 vs. 88%; p < 0.001). The present study showed that the non-IRA CTOs were associated with diabetes
mellitus and better collateral development compared with IRA-CTO. In diabetic patients,
the concomitant smoking use may be harmful by preventing endogenous cardioprotective
mechanisms.
Keywords
chronic total coronary occlusion - cardioprotection - diabetes
