Intravascular ultrasound and near-infrared spectroscopic features of coronary lesions with intraplaque haemorrhage

Intraplaque haemorrhage is considered a major contributor to lesion progression. We assessed coronary lesions with intraplaque haemorrhage using intravascular ultrasound (IVUS) and near-infrared spectroscopy (NIRS).

We evaluated coronary arteries from autopsy hearts using 40MHz IVUS and NIRS and compared the imaging findings to histopathology. A total of 2324 2-mm long histological segments from 101 coronary arteries from 56 autopsy hearts were included. Intraplaque haemorrhage was found pathologically in 0.8% (18/2324) of segments. Segments with intraplaque haemorrhage had more fibroatheromas (FAs) with a greater IVUS plaque burden, a greater prevalence of IVUS echolucent zones, and a higher NIRS-lipid core burden index (LCBI) compared to segments without intraplaque haemorrhage (FAs: 72.2% vs. 18.3%, P < 0.0001; plaque burden: 59.7% [95% confidence interval: 55.5, 64.0] vs. 48.6% [45.8, 51.3], P < 0.0001; echolucent zones: 88.9% vs. 2.8%, P < 0.0001; NIRS-LCBI: 176 [88, 264] vs. 72 [53, 91], P = 0.02). The 16 IVUS superficial echolucent zones with intraplaque haemorrhage had more late FAs but shorter echolucent zone lengths (0.9 mm [0.7, 1.1] vs. 1.7 mm [1.5, 1.9], P < 0.0001) compared to 65 IVUS superficial echolucent zones without intraplaque haemorrhage.

Intracoronary imaging features consistent with intraplaque haemorrhage included a greater plaque burden, a higher NIRS-LCBI, and a greater prevalence of IVUS echolucent zones compared to lesions without intraplaque haemorrhage.