Early assessment of myocardial contractility by contrast-enhanced magnetic resonance (ceMRI) imaging after revascularization in acute myocardial infarction (AMI)

Combination of magnetic resonance imaging and targeted contrast agent for the diagnosis of myocardial infarction

Myocardial infarction is one of the most common human cerebrovascular conditions and frequently leads to ischemic stroke. Evidence has indicated that magnetic resonance imaging (MRI) is a potential method for the diagnosis of patients with cardiovascular injury. However, the efficacy of MRI in diagnosing patients with myocardial infarction requires to be improved. In the present study, a novel nano-size contrast agent, a chitosan/Fe₃O₄-enclosed albumin (CFEA), was introduced that was used to quantify blood volume and permeability in the infarcted myocardium. A total of 68 patients with suspected myocardial infarction were recruited to analyze the efficacy of MRI combined with CFEA (MRI-CFEA). All patients received diagnosis by MRI and MRI-CFEA. It was revealed that MRI-CFEA provided a higher signal intensity than MRI in the same patients. It was demonstrated that the diagnostic efficacy of MRI-CFEA for patients with myocardial infarction was higher than that of MRI (P<0.05). By MRI-CFEA, 50/68 of cases with myocardial infarction were diagnosed, providing a significantly higher diagnostic rate compared with the 38/68 of cases diagnosed by contrast-enhanced MRI (P<0.01). MRI-CFEA successfully discriminated the infarcted regions based on a decreased fractional blood volume and increased permeability-surface (PS) area product in the infarcted myocardium. A pharmacodynamics analysis indicated that CFEA was eliminated within 24 h in all individuals. In conclusion, the present study provided a novel method to diagnose infarcted myocardium for patients with myocardial infarction, providing an imaging biomarker for the assessment of endothelial dysfunction in the clinic.