Background: It remains unclear whether spontaneous anterograde flow preserves myocardial fatty acid metabolism in patients with acute myocardial infarction (AMI).
Methods and results: The present study comprised 129 patients with a first anterior AMI in whom Thrombolysis in Myocardial Infarction (TIMI) 3 flow was obtained on the final angiogram: 28 patients with spontaneous anterograde flow and 101 patients with total occlusion on the initial angiogram. Thallium-201 (201Tl) and iodine-123-beta-methyl-p-iodophenyl penta-decanoic acid (123I-BMIPP) dual-isotope myocardial single-photon emission computed tomography (SPECT) was performed at 6.5+/-4.2 days after onset. The SPECT image was divided into 17 segments, and each segment was graded with scores between 0 and 4 (0, normal uptake; 4, defective). The sum of each score was defined as the total defect score (TDS). TDS values for 201Tl (9.0 +/-7.4 vs 16.8+/-12.2, p < 0.01) and 123I-BMIPP (19.3+/-11.6 vs 24.1 +/-10.4, p < 0.05) were significantly lower in patients with spontaneous anterograde flow than in those with total occlusion.
Conclusions: These results suggest that spontaneous anterograde flow of the infarct artery preserves not only myocardial perfusion but also fatty acid metabolism in patients with AMI. 123I-BMIPP SPECT image may underestimate the area at risk especially in patients with spontaneous anterograde flow.