BACKGROUND: Coronary artery disease (CAD) is known to be diffuse and can affect multiple arterial segments. However, findings of concomitant lesions in a single segment and no obstructions in other segments of the same patient are not unusual when assessing coronary angiographies. Because it is a luminogram, angiography has limitations for the diagnosis of CAD. In this study, intravascular ultrasound and virtual histology (IVUS-VH) were used to assess the presence and composition of atherosclerotic plaques in angiographically normal segments and in segments with lesions of patients with established CAD. METHODS: A total of 17 patients with obstructive CAD referred for angioplasty were submitted to IVUS-VH of the three major epicardial coronary arteries. After careful angiographic analysis, 32 angiographically normal segments were selected and compared to 19 segments with luminal stenosis > 70%. RESULTS: Mean plaque burden in angiographically normal segments was 47.3 ± 15.1%, whereas in segments with angiographic stenosis it was 76.2 ± 8.8% (P < 0.01). Plaque composition differed among segments. Plaques in angiographically normal segments had higher percentage of fibrofatty component (17 ± 11% vs. 11.4 ± 12%; P = 0.045) and lower percentage of necrotic component (13.1 ± 13% vs. 20.2 ± 12%; P = 0.03). CONCLUSIONS: In this pilot study, in a small group of patients with CAD, it was observed that angiographically normal segments often have atherosclerotic plaque. However, plaque composition was different in angiographically normal segments and those with angiographic stenosis, suggesting the coexistence of distinct stages of the atherosclerotic process in the same patient.
Plaque, atherosclerotic; Angiography; Coronary artery disease
