Multicompartmental Analysis of Late Contrast Enhancement in Areas of Myocardial Infarction Supplied by Chronically Occluded Coronary Arteries

Purpose: To analyze the relationship between late contrast enhancement (LCE) and the interstitial distribution volume (V-In.) of gadolinium (Gd) tracers in the myocardial infarction (MI) areas supplied by chronically occluded arteries from patients. In animal experimental models, LCE has already been shown to correspond to an enhanced V-In of Gd tracers and thus, to a decrease in the amount of intact cells. Materials and Methods: A multicompartmental analysis was applied to serial MRI images encompassing both infarct and remote areas and recorded with a conventional two-dimensional (2D) segmented inversion-recovery gradient-echo (IR-GRE) sequence during a 15-minute period following Gd-diethylenetriamine pentaacetic acid (Gd-DTPA) injection in 12 patients with Q-wave MI supplied by chronically occluded coronary arteries. Results: V-In from infarct tissue was: 1) higher than V-In,1 from remote areas (in % of myocardial volume: 74 +/- 16% vs. 20 +/- 7%, P < 0.001); and 2) correlated with the quantification of LCE between infarct and noninfarct areas at the 15th minute (R-2 = 0.63, P = 0.002). However, the difference in V-In between infarct and remote myocardium was a much better correlate of this quantified LCE (R-2 = 0.85, P < 0.001). Conclusion: Detection of LCE in the MI territories supplied by chronically occluded arteries relates to the difference in the Vi of tracers between the infarct and the noninfarct areas.