Prognostic value of 123-IODO-heptadecanoic acid imaging in patients with acute myocardial infarction.

This trial aimed to test if the half life of radioiodinated heptadecanoic acid (HDA) in acutely infarcted myocardium is of prognostic value. Twenty patients had an HDA scan and a MUGA scan within 6 days of acute myocardial infarction, eighteen of these had a visible defect on the HDA images. The mean half life of the areas of acute infarction (15.50 min +/- 7.82 min) was significantly shorter than that of normal myocardium (20.77 min +/- 4.00 min). The MUGA scan was repeated after 6 months in 15 patients. The mean acute infarct half life was longer in patients with an LVEF improvement of at least 5% at 6 months (16.92 min +/- 10.56 min), compared to those with a deterioration of more than 5% (11.75 min +/- 4.03 min), although the difference is not statistically significant. While the results in a few individuals suggested that the half life may be of prognostic significance, the variable response of the group reduced the ability of the half life to act as a prognostic indicator. Improvements in imaging and background subtraction techniques may be necessary before the half life is of practical value.