Ultrasound Bio-microscopy for Measurement of Coronary Artery Flow and Estimation of Infarct Size in a Mouse Model of Acute Myocardial Infarction

Extracellular matrix metalloproteinase inducer EMMPRIN, is highly expressed in patients with acute myocardial infarction (AMI), and induces activation of several matrix metalloproteinases (MMPs), including MMP-9 and MMP-13. To prevent Extracellular matrix degradation and cardiac cell death we targeted EMMPRIN with paramagnetic/fluorescent micellar nanoparticles with an EMMPRIN binding peptide AP9 conjugated (NAP9), or an AP9 scramble peptide as a negative control (NAPSC). NAP9 binds to endogenous EMMPRIN as detected by confocal microscopy of cardiac myocytes and macrophages incubated with NAP and NAPSC in vitro, and in vivo in mouse hearts subjected to left anterior descending coronary artery occlusion (IV injection 50mγ/Kg NAP9 or NAP9SC). Administration of NAP9 at the same time or 1 hour after AMI reduced infarct size over a 20% respect to untreated and NAPSC injected mice, recovered left ventricle ejection fraction (LVEF) similar to healthy controls, and reduced EMMPRIN downstream MMP9 expression. In magnetic resonance scans of mouse hearts 2 days after AMI and injected with NAP9, we detected a significant gadolinium enhancement in the left ventricle respect to non-injected mice and to mice injected with NAPSC. Late gadolinium enhancement assays exhibited NAP9-mediated left ventricle signal enhancement as early as 30 minutes after nanoprobe injection, in which a close correlation between the MRI signal enhancement and left ventricle infarct size was detected. Taken together, these results point EMMPRIN targeted nanoprobes as a new tool for the treatment of AMI.

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P3391Cholesterol crystals in culprit coronary artery with acute myocardial infarction and their relation to myocardial salvage

European Heart Journal ◽

10.1093/eurheartj/ehz745.0267 ◽

2019 ◽

Vol 40 (Supplement_1) ◽

Author(s):

T Nunohiro ◽

S Kuwasaki ◽

T Fukushima ◽

S Furudono ◽

H Suenaga ◽

...

Keyword(s):

Myocardial Infarction ◽

Acute Myocardial Infarction ◽

At Risk ◽

Coronary Artery ◽

Infarct Size ◽

Myocardial Salvage ◽

Area At Risk ◽

Risk Area ◽

Contrast Enhanced ◽

Delayed Enhancement Imaging

Abstract The involvement of cholesterol crystals (CCs) in plaque progression and destabilization of atherosclerotic plaques has been recently recognized. However, little is known about CCs and myocardial salvage in the Acute myocardial infarction (AMI) patients. This study aimed to evaluate the association between the existence of CCs at the site of culprit coronary artery and myocardial salvage index (MSI).To investigate, we applied the diagnostic resources of Optical Coherence Tomography (OCT). Methods This study included 53 AMI patients (90% with STEMI) who underwent primary PCI within 24h of onset. 53 STEMI patients underwent magnetic resonance imaging (CMR) of 5th days and 3 months after PCI. Infarct size was measured on delayed-enhancement imaging, and area at risk was quantified on T2-weighted imaging. MSI was calculated as [area at risk − infarct size] × 100/area at risk. 3 months CMR with contrast-enhanced imaging of late gadolinium enhancement-LGE. Patients were divided 2 groups according to the existence of CCs at the site of culprit coronary artery. Results CCs occurs in 26 of 53 (49%). Acute 5th days risk area (13.5±4.1 vs 12.6±4.9, P=0.48) and 3months infarct size (5.3±3.5 vs 7.0±3.2, P=0.066) were not significant between CCs and no CCs group. But salvage index were significantly lower in patients with CCs group (47.7±17.5% vs 60.1±20.2%, P=0.021) Conclusion Salvage index in patients that CCs were found by the OCT analysis, remain low after AMI. This study demonstrates the potential correlation between the myocardial salvage and vulnerable morphological features of culprit lesion to the presence of CCs with AMI patients.

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