Prediction of Coronary Artery Lesions in Unstable Angina by Iodine 123 Beta-Methyl Iodophenyl Pentadecanoic Acid (BMIPP),a Fatty Acid Analogue,Single Photon Emission Computed Tomography at Rest

Abstract

Iodine 123 beta-methyl iodophenyl pentadecanoic acid (¹²³I-BMIPP), a beta-methyl- branched fatty acid analogue, has been proven by experimental studies to reveal abnor malities in fatty-acid-related metabolism. This study was undertaken to validate the accuracy and limitations of ¹²³I-BMIPP imaging at rest in detecting myocardial metabolic abnormalities and predicting coronary lesions in unstable angina (UA). One hundred UA patients without prior myocardial infarction were studied. ¹²³I-BMIPP and thallium 201 chloride (²⁰¹TlCl) imaging with single photon emission computed tomography (SPECT) and coronary and left ventricular cineangiography (LVC) were performed 1 week after the last episode of angina. There was reduced uptake of ¹²³I-BMIPP imaging in 70 patients, reduced uptake of ²⁰¹TICI in 41, and abnormal LVC contraction in 49 patients. There were significant increases in severity scores of ¹²³I-BMIPP imaging along with increases in the number of stenosed coronary arteries and the severity of stenosis in indi vidual coronary arteries. There was a significant reduction in ¹²³I-BMIPP severity scores 1 month after percutaneous transluminal coronary angioplasty (p<0.01) and a significant correlation between the severity scores of ¹²³I-BMIPP and LVC (r=0. 579, p<0.001). Overall rates of sensitivity and specificity in detecting significant coronary stenosis by ¹²³I-BMIPP imaging were 74% and 86%, respectively, whereas rates of sensitivity and specificity in detecting significant coronary stenosis by ²⁰¹TlCl were 31% and 91%, respec tively. ¹²³I-BMIPP sensitivity increases to 86% if only advanced coronary stenosis of >90% is included. In conclusion, ¹²³I-BMIPP myocardial imaging is an effective method of predicting coronary artery lesions of UA patients without provocative test.