Myocardial perfusion assessment in the infarct core and penumbra zones in an in-vivo porcine model of the acute, sub-acute, and chronic infarction

Abstract

Objectives To assess the longitudinal changes of microvascular function in different myocardial regions after myocardial infarction (MI) using myocardial blood flow derived by dynamic CT perfusion (CTP-MBF), and compare CTP-MBF with the results of cardiac magnetic resonance (CMR) and histopathology. Methods The CTP scanning was performed in a MI porcine model 1 day (n = 15), 7 days (n = 10), and 3 months (n = 5) following induction surgery. CTP-MBF was measured in the infarcted myocardium, penumbra, and remote myocardium, respectively. CMR perfusion and histopathology were performed for validation. Results From baseline to follow-up scans, CTP-MBF presented a stepwise increase in the infarcted myocardium (68.51 ± 11.04 vs. 86.73 ± 13.32 vs. 109.53 ± 26.64 ml/100 ml/min, p = 0.001) and the penumbra (104.92 ± 29.29 vs. 120.32 ± 24.74 vs. 183.01 ± 57.98 ml/100 ml/min, p = 0.008), but not in the remote myocardium (150.05 ± 35.70 vs. 166.66 ± 38.17 vs. 195.36 ± 49.64 ml/100 ml/min, p = 0.120). The CTP-MBF correlated with max slope (r = 0.584, p < 0.001), max signal intensity (r = 0.357, p < 0.001), and time to max (r = − 0.378, p < 0.001) by CMR perfusion. Moreover, CTP-MBF defined the infarcted myocardium on triphenyl tetrazolium chloride staining (AUC: 0.810, p < 0.001) and correlated with microvascular density on CD31 staining (r = 0.561, p = 0.002). Conclusion CTP-MBF could quantify the longitudinal changes of microvascular function in different regions of the post-MI myocardium, which demonstrates good agreement with contemporary CMR and histopathological findings. Key Points • The CT perfusion–based myocardial blood flow (CTP-MBF) could quantify the microvascular impairment in different myocardial regions after myocardial infarction (MI) and track its recovery over time. • The assessment of CTP-MBF is in good agreement with contemporary cardiac MRI and histopathological findings, which potentially facilitates a rapid approach for pathophysiological insights following MI.