Abstract 619: Non Invasive Assessment of Plaque Imaging in Non Culprit Artery of Acute Coronary Syndrome by Cardiac Magnetic Resonance
The identification of vulnerable plaque can be an important step in preventing acute coronary syndrome (ACS). Last year we demonstrated the non-invasive tissue characterization in coronary arterial wall by contrast free cardiac magnetic resonance imaging (CMR) and reported spot high signal (SHS) showed strong possibility of plaque hemorrhage. We assess that CMR can detect the vulnerable patients who are prone to the development of coronary events. Methods: We enrolled 85 patients who’ve documented angiographically significant coronary artery disease. One hundred twenty five segments of 37 patients with ACS (mean age 61 year-old, female 4) and 173 segments of 48 patients with non-ACS (mean age 66 year-old, female 7) were analyzed. Non-contrast enhanced images were obtained using a commercial 1.5T MR imager and five-element cardiac coils. Non culprit coronary arterial walls were visualized with a navigator-gated balanced TFE sequence of three point black blood method. Results: According to the relative signal intensity (RSI), we defined the SHS as a stronger RSI (8>RSI). More than two radiologist read films and good agreement between observers in the image analysis (r = 0.79, P < 0.001). Thirty three of the 125 segments (26.4%) with ACS had a greater volume of SHS plaques in the non-culprit coronary arteries whereas 20 of the 173 segments with non-ACS (10.6%) had SHS plaques (p<0.01). Moreover the signal intensity of SHS in ACS was higher than that in non-ACS (RSI 24+−4 and 12+−4, p<0.01). During a half year follow-up after CMR examination in ACS, one patient developed ACS again just in the region where SHS had been identified. Conclusion: Patients with ACS have more vulnerable plaques with plaque hemorrhage in non-culprit coronary arteries. CMR may detect the vulnerable patients who need more careful management.