Iodine-123 phenylpentadecanoic acid: Detection of acute myocardial infarction and injury in dogs using an iodinated fatty acid and single-photon emission tomography

The ability of an iodinated fatty acid, iodine-123 Phenylpentadecanoic acid (1–123 PPA), and single-photon emission computed tomography (SPECT) to detect myocardium injured by temporary or permanent coronary arterial occlusion was evaluated. In 5 control dogs, 11 dogs that underwent 90 to 120 minutes of fixed left anterior descending coronary artery (LAD) occlusion, and 8 dogs that underwent 90 minutes of temporary LAD occlusion and up to 90 minutes of reflow, 2 to 6 mCi of 1–123 PPA were injected and the dogs were imaged with SPECT. Control dogs showed relatively uniform uptake and clearance of 1–123 PPA in similar left ventricular (LV) regions. Dogs with permanent LAD occlusion were identified by computer algorithm as having regions of decreased 1–123 PPA uptake in the infarct-related area and a reduced rate of 1–123 PPA clearance (−9.4% in infarct sectors [washin], +3.7% in sectors adjacent to the area of infarction, and +15.4% in control LV sectors [p <0.01]). Dogs with temporary LAD occlusion and reperfusion had decreased clearance of 1–123 PPA from the regions with infarction; 1–123 PPA clearance was −5.2 ± 16.4% in infarct sectors, 12.7 ± 7.4% in periinfarct zones, and 30.4 ± 12% in control LV regions. These data demonstrate that tomographic analysis of 1–123 PPA uptake and clearance permits the relatively noninvasive detection of LV myocardium injured by permanent or temporary LAD occlusion and reperfusion.