Near-infrared spectroscopy for the detection of lipid core coronary plaques

Abstract

Lipid core coronary plaques (LCPs), which cannot be reliably detected by conventional diagnostic measures, are widely considered to be the cause of most acute coronary syndromes. Accumulating evidence also indicates that LCPs may increase the risk of stenting complications. A catheter-based near-infrared spectroscopy (NIRS) system is now available for the detection of LCPs in the arteries of patients undergoing coronary angiography. The system, which uses the well-documented ability of NIRS to determine the chemical composition of unknown substances, has been validated in an autopsy study and a clinical trial. The system has now been used in more than 300 patients and has provided novel information for use in assessment of coronary disease. Multiple studies are in progress to assess the full clinical benefi t of NIRS for the goals of 1) improving the safety of stenting, 2) preventing a second coronary event in patients with known coronary disease, and 3) use as a possible component in a strategy for the primary prevention of coronary events.

Near-Infrared Spectroscopy (NIRS): A Novel Tool for Intravascular Coronary Imaging

“…In August 2005, an improved ultrafast NIR system prototype was developed with a faster scanning laser and was later used in a feasibility study of 10 patients in 2006 (Lahey Clinic, Burlington, MA). The trial confirmed the safety of the newer improved device and showed its ability to discriminate between signals obtained in the artery and those from blood alone, with no measurable artifacts of motion [16,40]. A subsequent pivotal study, the SPECTACL (SPECTroscopic Assessment of Coronary Lipid) clinical study, was performed to validate the accuracy of LCP-detected NIRS signals collected in coronary arteries of 106 patients [10].…”

“…The first use of the NIRS system in coronary arteries of living humans was performed in six patients undergoing elective PCI for stable angina using an early prototype (2001; Lahey Clinic, Burlington, MA) [13,16,40]. No device-related adverse events occurred, showing the safety and feasibility of the system to distinguish spectra measured through blood.…”

Association of coronary lipid core plaque with intrastent thrombus formation

“…Blocks correspond to one of four discrete bins, each represented by a distinct color (red, orange, tan, and yellow, in increasing order of LCP probability). An additional metric is the lipid core burden index (LCBI), which is computed as the fraction of valid pixels in the chemogram that exceed a LCP probability of 0.6, multiplied by 1,000 . For the present study, a large LCP by NIRS was defined as at least three 2‐mm yellow blocks on the NIRS block chemogram with >200° angular extent.…”

The Year in Intracoronary Imaging

“…Diffuse reflectance NIR spectroscopy. A catheterbased NIR spectroscopy system has been developed to identify lipid-core plaque in coronary arteries (58). An NIR scan is performed through blood in a manner similar to that used for IVUS and is displayed as a map of the artery called a chemogram (59).…”