Experimental and clinical experience with iodine 123-labeled iodophenylpentadecanoic acid in cardiology

Iodine 123-labeled iodophenylpentadecanoic acid (IPPA) has been synthesized for investigating myocardial free fatty acid (FFA) metabolism. The diagnostic application of labeled FFA in heart disease may be important, because FFA is the preferred substrate of cardiac energy metabolism at rest in the fasting state. In addition, regional myocardial FFA uptake and regional myocardial blood flow are tightly coupled in normal myocardium with beta-oxidation, which is extremely sensitive to oxygen deprivation. This article outlines basic physiologic pathways of cardiac IPPA metabolism in normal, acutely ischemic, and reperfused viable myocardium and summarizes the results of experimental studies in animals, validating the application of IPPA as an 123I-labeled fatty acid analog. In addition, the most important clinical studies indicating the clinical use of IPPA for diagnosis of coronary heart disease and myocardial viability are presented.