Abstract 3069: Scanning Near-InfraRed (NIR) Spectroscopy of Coronary Arteries for Detection of Lipid-Rich Plaque in Patients Undergoing PCI - Early Results of the SPECTACL Study
Background: New methods are needed to identify vulnerable plaques. SPECTACL is an ongoing multicenter study of patients (pts) undergoing PCI using a catheter-based (3.2 Fr) near infrared (NIR) spectroscopy system that can scan through blood and identify plaque composition. We report our early experience.
Methods and Results: Scanning NIR spectroscopy with motorized pullback was performed in culprit arteries of 22 pts with stable angina or acute coronary syndrome. Feasibility study in the first 10 pts indicates that the procedure is safe, the catheter was easy to place, and high quality measurements of the arterial wall were acquired through blood during cardiac motion. Mahalanobis Distance and Spectral-F-Ratio metrics for spectra obtained in vivo were significantly elevated compared to values obtained in a blood well (BW), indicating that in vivo spectra, which contain the signature of the artery wall, can be distinguished from BW spectra. Early analysis in additional 12 pts indicates the ability to measure regional differences within arterial segments. Data have been analyzed on 5 pts using a preliminary chemometric algorithm to detect lipid-rich signal. The mean scanned length was 45.4 mm (median 34.3 mm). Using lipid-peak-height signal, 4 of 5 pts showed lipid peak height at the culprit lesion (3 of 4 ACS patients). Using mean reflectance, all 5 pts showed lipid peak height at the culprit lesion (Figure⇓).
Conclusions: Intracoronary NIR spectroscopy is feasible and safe in patients and can obtain spectral data through blood from the coronary artery wall. Further experience with the device will be gained in this study to confirm its ability to detect lipid-rich plaque.