Evaluation of combined near-IR spectroscopic (NIRS)-IVUS imaging as a means to detect lipid-rich plaque burden in human coronary autopsy specimens

Intracoronary near-infrared spectroscopy (NIRS) can identify lipid in the coronary arteries, but lacks depth resolution. A novel catheter is currently in clinical use that combines NIRS with intravascular ultrasound (IVUS), which provides depth-resolved structural information via the IVUS modality. A measure designated as lipid-rich plaque burden (LRPB) has been proposed as a means to interpret the combined acoustic and optical information of NIRS-IVUS. LRPB is defined as the area created by the intersection of the NIRS lipid-rich arc with the corresponding IVUS-measured plaque burden. We determined the correlation in human coronary autopsy specimens between LRPB, a measure of lipid presence and extent available via intravascular imaging in patients, and the area of lipid-rich plaque as determined by the gold-standard of histology. Fifteen artery segments from 8 human autopsy hearts were imaged with the NIRS-IVUS system (TVC Imaging System, Infraredx Inc., Burlington, MA). Arteries were imaged in a specialty fixture that assured accurate co-registration between imaging and histology. The arteries were then fixed and divided into 2 mm blocks for histological staining. Pathological contouring of lipid-rich areas was performed on the stained thin sections for 54 lipid-rich blocks. Computation of LRPB was performed on transverse NIRS-IVUS frames corresponding to the histologic sections. The quantified LRPB was frequently higher than the lipid-rich plaque area determined by histology, because the region denoted by the EEL and lumen within the NIRS lipid-rich arc is not entirely comprised of lipid. Overall, a moderate to strong correlation (R = 0.73) was found between LRPB determined by NIRS-IVUS imaging and the lipid-rich plaque area determined by histology. LRPB, which can be measured in patients with NIRS-IVUS imaging, corresponds to the amount of lipid-rich plaque in a coronary artery. LRPB should be evaluated in prospective clinical trials for its ability to identify vulnerable plaques.

[1]  G. Stone,et al.  Plaque Characterization to Inform the Prediction and Prevention of Periprocedural Myocardial Infarction During Percutaneous Coronary Intervention: The CANARY Trial (Coronary Assessment by Near-infrared of Atherosclerotic Rupture-prone Yellow). , 2015, JACC. Cardiovascular interventions.

[2]  R. Virmani,et al.  Lessons from sudden coronary death: a comprehensive morphological classification scheme for atherosclerotic lesions. , 2000, Arteriosclerosis, thrombosis, and vascular biology.

[3]  R. Virmani,et al.  Combined IVUS and NIRS detection of fibroatheromas: histopathological validation in human coronary arteries. , 2015, JACC. Cardiovascular imaging.

[4]  K. Huynh.  Imaging: Combining IVUS and NIRS improves accuracy of fibroatheroma detection , 2015, Nature Reviews Cardiology.

[5]  J. Harnek,et al.  Coronary liposuction during percutaneous coronary intervention: evidence by near-infrared spectroscopy that aspiration reduces culprit lesion lipid content prior to stent placement. , 2015, European heart journal cardiovascular Imaging.

[6]  James E. Muller,et al.  Detection of lipid core coronary plaques in autopsy specimens with a novel catheter-based near-infrared spectroscopy system. , 2008, JACC. Cardiovascular imaging.

[7]  J. Ware,et al.  Large lipid-rich coronary plaques detected by near-infrared spectroscopy at non-stented sites in the target artery identify patients likely to experience future major adverse cardiovascular events. , 2016, European heart journal cardiovascular Imaging.

[8]  C. Grines,et al.  Analysis of target lesion length before coronary artery stenting using angiography and near-infrared spectroscopy versus angiography alone. , 2012, The American journal of cardiology.

[9]  Samin K. Sharma,et al.  Changes in plaque lipid content after short-term intensive versus standard statin therapy: the YELLOW trial (reduction in yellow plaque by aggressive lipid-lowering therapy). , 2013, Journal of the American College of Cardiology.