Clinical significance of decreased myocardial uptake of 123I-BMIPP in patients with stable effort angina pectoris.

The aim of this study was to assess the feasibility of resting myocardial fatty acid metabolic imaging with 123I-beta-methyliodophenyl-pentadecanoic acid (123I-BMIPP) for the detection of patients with stable effort angina pectoris and to clarify the clinical significance of abnormal 123I-BMIPP images. Myocardial imaging with 123I-BMIPP at rest and 99Tcm-methoxyisobutyl isonitrile (99Tcm-MIBI) at rest and during treadmill exercise was performed in 46 patients with suspected effort angina pectoris. Resting 123I-BMIPP imaging detected 43% (17/40) of patients with significant (> or = 50%) coronary artery stenosis and 59% (17/29) of patients with exercise-induced myocardial ischaemia. The patients with abnormal 123I-BMIPP images terminated exercise after a shorter period (4.5 +/- 2.6 vs 6.7 +/- 4.1 min; P < 0.01) and at a lower rate pressure product (16,124 +/- 5211 vs 20,246 +/- 6564 mmHg x beats min-1; P < 0.01) than those with normal 123I-BMIPP images. The presence of ST depression during the exercise test (77 vs 52%; P < 0.05), severe coronary stenosis exceeding 90% (88 vs 43%; P < 0.01), collateral vessels (35 vs 9%; P < 0.01) and a wall motion abnormality of hypokinesis/akinesis (53 vs 30%; P < 0.05) were more frequently seen in patients with abnormal 123I-BMIPP images than in those with normal images. Resting 123I-BMIPP imaging was able to detect the presence of coronary artery stenosis and exercise-induced myocardial ischaemia with moderate sensitivity, and to determine the functional severity of coronary artery disease.