Objectives This study was designed to investigate the relationship between intravascular ultrasonic plaque morphology and quantitative acoustic densitometry by integrated backscatter (IBS) of carotid plaque in patients with coronary artery disease.
Methods Intravascular ultrasound (IVUS) were performed in consecutively enrolled 31 patients with coronary heart disease and intravascular ultrasonic plaque morphology was analysed. According to the morphologic types of plaque detected by IVUS, patients were divided into non-vunerable plaque group (n = 16) and vunerable plaque group (n = 15). we used high-frequency ultrasound to obtain intima-media thickness (IMT) and carotid plaque forming was defined as IMT >1.2 mm. All carotid plaque were assessed by IBS analysis and calibrated integrated backscatter (CIBS) was obtained. The changes of detective rates and CIBS of carotid plaque are compared between non-vunerable plaque group and vunerable plaque group. Correlative analysis was done between coronary plaque morphologic characterisation [plaque sectional cross area (PSCA), plaque eccentricitic index (PEI), plaque burden (PB), remodelling index (RI), fibrous cap thickness] and CIBS.
Results The detective rate of carotid plaque was higher in vunerable plaque group than non-vunerable plaque group (73.33% vs 31.25%, p = 0.032); CIBS of carotid plaque in vunerable plaque group was significantly lower than that in non-vunerable plaque group (-15.43 ± 3.58 dB vs -9.58 ± 2.75 dB, p = 0.006). CIBS of carotid plaque has negative correlation to RI (r = -0.639, p = 0.008) and positive correlation to fibrous cap thickness (r = 0.662, p = 0.005); CIBS of carotid plaque has no correlation to PSCA (r = -0.154, p = 0.568) and PB (r = - 0.284, p = 0.287) and PEI (r = 0.397, p = 0.128).
Conclusions CIBS of carotid plaque significantly decrease in patients with coronary vunerable plaque. Quantitative acoustic densitometry by IBS analysis may serve as an non-invasive predictor for vunerable plaque in patients with coronary artery disease.