The incidence of discrepant regional myocardial uptake between 201 thallium and 123 I-BMIPP SPECT in patients with coronary heart disease

Myocardial perfusion and fatty acid uptake at rest were assessed by SPECT with ²⁰¹Tl (Tl) and ¹²³I-BMIPP (BMIPP) in 50 consecutive patients with coronary heart disease. Discrepant regional myocardial uptake was observed in 19 patients and classified into the following two groups: mismatch (MM; Tl uptake > BMIPP uptake, n = 14, mean age, 66 years) and paradoxical mismatch (PM; Tl uptake < BMIPP uptake, n = 5, mean age, 68 years). In the MM group, 77% was single- or zero-vessel disease and the artery-perfused region in the mismatched area was almost always ischemia related. Sixty percent of the regions observed with the PM were related to the inferior wall. In the PM group, 80% of cases were associated with multivessel stenoses and 60% of cases was suffered from ischemic attack within a week before scintigraphy. In conclusion, mismatch was related to abnormal fatty acid uptake caused by coronary heart disease. Although the paradoxical mismatch might mainly be related to diaphragmatic attenuation of Tl scans and augmented artifacts of BMIPP scans in the inferior wall, we should not overlook severe coronary heart disease in patients with paradoxical mismatched phenomenon.