Objectives: To study the relationship between lesion vessel area and myocardial salvage assessed by myocardial single photon emission computed tomography (SPECT) in acute myocardial infarction with stenting after thrombectomy.
Methods: This study included 71 patients who underwent stenting after thrombectomy for acute myocardial infarction. Intravascular ultrasound (IVUS) was performed after thrombectomy. Patients were classified into two groups: the High group with external elastic membrane cross-sectional area (EEM-CSA) of the lesion > or = 18 mm2 (34 patients) and the Low group with EEM-CSA < 18 mm2 (37 patients). Dual isotope myocardial SPECT imaging was undertaken by perfusion SPECT (201Tl or 99mTc-MIBI) and 123I-15-(p-iodophenyl)-3-(R,-S)-methylpentadecanoic acid (BMIPP). The image of the left ventricular myocardium was divided into 17 segments to calculate total defect score using a 5-grade assessment (0: normal-4: defect). Differences in total defect score of perfusion SPECT and 123I-BMIPP was defined as mismatch.
Results: Culprit lesion morphology was assessed by IVUS. A higher incidence of lipid pool-like images (47% vs 5%, p < 0.01) was observed in the High group. The results of myocardial SPECT study revealed no difference in the total defect score of 123I-BMIPP (18.3 +/- 5.5 vs 17.3 +/- 6.3 points) but the mismatch in total defect score of perfusion SPECT and 123I-BMIPP was significantly lower in the High group (3.8 +/- 3.9 vs 7.7 +/- 4.2 points, p < 0.05).
Conclusions: Patients with a high culprit lesion vessel area show fewer beneficial effects in myocardial salvage compared with those with low vessel area as assessed by myocardial SPECT in acute myocardial infarction with stenting after thrombectomy.