Detection of viability and clinical implications using positron emission tomography/magnetic resonance imaging in patients with acute myocardial infarction

Abstract

Abstract Background PET/MRI has been used for almost 10 years to assess myocardial perfusion, viability, and inflammatory and infiltrative processes of heart. By combining the advantages of FDG-PET and LGE-MRI, it is already the modality of choic for myocardial viagility and inflammatory disease [1]. The purpose of this study is to evaluate the role of viability on PET/MRI to predict improvement if echocardiographic findings such as regional wall motion abnormality (RWMA) after successful percutaneous coronary intervention (PCI) for patients with acute myocardial infarction (AMI). Method A total of 154 patients with AMI who was performed cardiac PET/MRI within 7 days after PCI were enrolled. We performed TTE twice before and after PCI in 103 patients. We categorized these patients according to presence of viability on PET-MRI: group A (N=53, patients with viability on PET-MRI) and group B (N=50, patients without viability on PET-MRI) and compared. The primary end point is improvement of regional wall motion abnormality (RWMA) on TTE. We set the definition of viability in PET/MRI as FDG uptake is 50% or more and LGE transmurality is 50% or less [2]. Results Clinical and angiographic findings were similar between the two groups except peak high sensitivity Troponin-I(hs TnI). The value of peak hs TnI of Group A was significant lower than that of Group B(20.22±26.42 vs. 39.28±30.59, p=0.001). Among 53 patients in group A, 17 patients (32.1%) showed the result of slight improvement of RWMA on TTE and 13 patients (24.5%) showed result of disappeared RWMA on TTE. In contrast, among 50 patients in group B, 19 patients (38%) showed the result of slight improvement and only 4 patients (8%) showed result of disappeared RWMA on TTE. The proportion of patients who showed slight improvement of RWMA between two groups are not statistically significant (32.1% vs. 38%, p=0.529). But, the proportion of patients who showed disappeared RWMA between two groups are statistically significant (24.5% vs. 8%, p=0.024). The value of improvement of LVEF of Group A is significantly higher than that of Group B(6.89±8.26 vs. 3.86±6.55, p=0.043). Conclusions PET/MRI is useful tool to detect viability in patients with AMI. It seems to be predictable to improve cardiac function for the patients with viability on PET-MRI.Baseline characteristicsPrimary endpoint