CT coronary angiography identified a significant number of coronary plaques in nonstenotic coronary arteries that were underestimated by conventional coronary angiography, according to results of a study.
“The aim of [our] study was to evaluate the presence and morphological characteristics of coronary atherosclerosis by means of CT coronary angiography in patients with acute MI documented by means of late-gadolinium-enhanced cardiac magnetic resonance, but without any significant coronary stenosis at coronary angiography,” Annachiara Aldrovandi, MD, PhD, of the division of cardiology, Azienda Ospedaliero-Universitaria di Parma, Italy, and colleagues wrote in the study.
The researchers examined 50 patients diagnosed with acute MI, but without significant coronary stenosis at coronary angiography, who underwent late gadolinium-enhanced magnetic resonance (LG-CMR) and CT coronary angiography (CTCA); all patients had an area of MI identified by LG-CMR. Coronary segments were assessed for the presence of plaques.
One hundred one plaques were identified by CTCA and 41 by coronary angiography. Of those detected by CTCA, 60.4% were located in infarct-related arteries and 39.6% in noninfarct-related arteries. In infarct-related arteries, 22 plaques were calcified, 22 were noncalcified and 17 were mixed. In the noninfarct-related arteries, 27 plaques were calcified, eight were mixed and five were noncalcified (P=.005).
Mean plaque area was greater in infarct-related arteries compared with noninfarct-related arteries (6.1 ± 5.4 mm2 vs. 4.2 ± 2.1 mm2 ; P=.03). The researchers found no significant difference in mean percentage stenosis between the two artery types (33.5 ± 14.6% vs. 31.7 ± 12.2%; P=.59), but significant differences in mean remodeling index (1.25 ± 0.41 vs. 1.08 ± 0.21; P=.01).
“Investigating the etiology of acute MI in this setting is very important because the prognosis is not benign and the recurrence of CV events is significant with a 1-year risk of ischemic events of 4.7%,” the researchers wrote. “Identifying or excluding coronary atherosclerosis at an early stage may be useful to establish an appropriate therapeutic strategy for the secondary prevention of ischemic events.”
Disclosure: One of the researchers is a consultant for Guerbet and has received a research grant from GEHC.