Combined IVUS and NIRS Detection of Fibroatheromas: Histopathological Validation in Human Coronary Arteries | Journal Scan

Study Questions:

What is the accuracy of grayscale intravascular ultrasound (IVUS) and near-infrared spectroscopy (NIRS) for detection of fibroatheroma (FA)?

Methods:

The authors compared IVUS-attenuated plaque and NIRS-LRP (lipid-rich plaques, yellow or tan block chemogram) with histopathology in 1,943 sections of 103 coronary arteries from 56 autopsied hearts.

Results:

Both IVUS-superficial attenuation and NIRS-LRP showed high specificity of approximately 95%, whereas the sensitivity for both IVUS and NIRS was low for detecting FAs (36% vs. 47%; p = 0.001). Compared with FA sections with superficial attenuation, FA sections without superficial attenuation had a smaller plaque burden (57.1% vs. 67.7%), a larger arc of calcium, and a lower prevalence of a >20% histological necrotic core (28% vs. 50%) or late FA (14% vs. 37%; all p < 0.05). When sections showed either IVUS attenuation or NIRS-LRP, the sensitivity for predicting an FA was significantly higher (63%) compared with IVUS attenuation alone or NIRS-LRP alone. When sections showed both IVUS attenuation and NIRS-LRP, the positive predictive value improved compared with IVUS attenuation alone (84% vs. 66%; p < 0.001) or NIRS-LRP alone (84% vs. 65%; p < 0.001).

Conclusions:

A combination of NIRS-LRP and IVUS was more accurate than either modality individually for predicting plaque containing a necrotic core or a large lipid pool.

Perspective:

High-quality imaging of vulnerable plaque has the potential to guide early phase assessment of plaque-modifying drugs and possibly guiding clinical care in a small subset of patients. This study suggests that a combination of IVUS and NIRS is better than either strategy, and the availability of a catheter that permits dual modality imaging should make it easier to acquire this information. Further studies are needed to establish the clinical utility and cost-effectiveness of this tool.

Keywords: Autopsy, Calcium, Dietary, Catheters, Coronary Vessels, Cost of Illness, Diagnostic Imaging, Lipids, Plaque, Atherosclerotic, Spectroscopy, Near-Infrared, Prevalence


< Back to Listings