Research Article: Assessment of myocardial perfusion using dual-source computed tomography myocardial perfusion imaging in a goat model of reperfusion injury induced by distal microembolization
Abstract:
Myocardial ischemia–reperfusion injury (MIRI) contributes to adverse outcomes after acute myocardial infarction. Microvascular obstruction (MVO), a key component of MIRI, impairs myocardial perfusion despite successful epicardial revascularization. This study aimed to establish a reproducible large-animal model of embolization-induced MVO and evaluate myocardial perfusion heterogeneity using dual-source CT myocardial perfusion imaging (DSCT-MPI).
Eight male Saanen goats underwent 30?min of left circumflex artery occlusion followed by distal microcatheter injection of 20- ? m polystyrene microspheres to induce reperfusion-associated MVO. DSCT-MPI was performed immediately after model establishment, with myocardial perfusion assessed by iodine distribution. Pathology was evaluated using triphenyltetrazolium chloride and hematoxylin–eosin staining, and Bcl-2, Bax, and caspase-3 were quantified. Receiver operating characteristic (ROC) analysis was used to determine the iodine concentration threshold for infarcted myocardium.
Seven of eight goats survived and underwent DSCT-MPI. Of 119 myocardial segments, 39 were infarcted, 14 were non-infarcted hypoperfused segments consistent with distal MVO, and 66 were normal. Binary ROC and diagnostic-performance analyses included the 39 infarcted and 66 normal segments, excluding the 14 MVO-consistent segments. At an iodine concentration cutoff of 1,582??g/cm 3 , DSCT-MPI achieved 89.7% sensitivity, 90.9% specificity, and an AUC of 0.848 (95% CI, 0.736–0.959), with substantial histopathological agreement ( ? =?0.798). Infarcted myocardium showed reduced Bcl-2 and increased Bax and caspase-3 expression. The 14 hypoperfused segments without TTC-confirmed necrosis were classified as MVO-consistent rather than CMD.
A minimally invasive, reproducible goat model of embolization-induced myocardial reperfusion injury was established. DSCT-MPI identified infarcted myocardium and non-infarcted hypoperfused regions consistent with distal MVO, demonstrating post-reperfusion perfusion heterogeneity without supporting CMD. Because no direct CMR comparison was performed, these findings should be considered exploratory pathology-based validation.
Introduction:
Myocardial ischemia–reperfusion injury (MIRI) contributes to adverse outcomes after acute myocardial infarction. Microvascular obstruction (MVO), a key component of MIRI, impairs myocardial perfusion despite successful epicardial revascularization. This study aimed to establish a reproducible large-animal model of embolization-induced MVO and evaluate myocardial perfusion heterogeneity using dual-source CT myocardial perfusion imaging (DSCT-MPI).
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