Exercise β-methyl iodophenyl pentadecanoic acid (BMIPP) and resting thalium delayed single photon emission computed tomography (SPECT) in the assessment of ischemia and viability

To clarify the significance of exercise BMIPP (β-methyl iodophenyl pentadecanoic acid) and resting Tl delayed single photon emission computed tomography (SPECT) in the assessment of ischemia and viability, we studied maximal exercise-loading BMIPP SPECT following rest-injected Tl 3 h SPECT in 11 control subjects, 20 patients with effort angina and 38 patients with old myocardial infarction. The left ventricular wall on ECT was divided into 9 segments. BMIPP and Tl uptake were scored as 0=normal, 1=reduced, 2=severely reduced, or 3=absent. Discordance was defined as when segments with a reduced BMIPP uptake had a better resting Tl uptake. Significant coronary artery stenosis was defined as stenosis of 75% or greater on coronary arteriogram. Left ventricular wall motion was assessed as either normokinesis, hypokinesis, severe hypokinesis, akinesis or dyskinesis on left ventriculogram. When discordance was considered to be a marker of ischemia, the sensitivity and specificity in effort angina and control subjects were 95.2% and 84.6% for patients and 83.9% and 94.4% for diseased vessels, respectively. There were no differences between the sensitivity and specificity in left anterior descending artery (LAD), Ieft circumflex artery (LCx) and right coronary artery (RCA) Iesions (83.3%, 95.5% in LAD, 83.3%, 95.5% in LCx, 85.7%, 92.6% in RCA, respectively). All of the patients with old myocardial infarction had reduced exercise BMIPP uptake in infarcted regions. In old myocardial infarction, 35 patients had segments with discordant uptake. Discordance was observed in 75 (91.5%) of 82 segments with hypokinesis, and in 24 (92.3%) of 26 segments with severe hypokinesis. Even among the 36 segments with akinesis or dyskinesis, 25 (69.0%) had discordant uptake. When discordance in the infarcted region was considered to be a marker of viability, regions with severe asynergy showed a high possibility of viability. Thus, discordant uptake on exercise BMIPP and resting Tl delayed SPECT may be a useful marker of ischemia in effort angina and of viability in old myocardial infarction. (Jpn Circ J 1996; 60: 17 - 26)