Early Assessment Of Subclinical Cardiac Involvement In Immune-Mediated Myopathy At 3T Cardiac Magnetic Resonance

Part Ⅰ Comparative study of clinical examination techniques for assessing subclinical heart injury in immune-mediated myopathyAims: Immune-mediated myopathy is associated with an increased incidence and mortality of heart disease,so early screening for cardiac involvement is critical.At present,electrocardiogram and echocardiography are often used for clinical screening of cardiac involvement,but they all have certain limitations.Cardiac magnetic resonance can provide histological features of myocardium.We aimed to evaluate the accuracy of traditional methods for diagnosing heart injury in immune-mediated myopathy compared with cardiac magnetic resonance imaging.Methods: Patients with immune-mediated myopathy who underwent cardiac magnetic resonance in our hospital during 2016.1-2018.12 were collected in our study.The electrocardiogram,echocardiography and cardiac magnetic resonance imaging data of all the patients were analyzed.Results: A total of forty patients with immune-mediated myopathy were enrolled for our study,all the patients underwent cardiac magnetic resonance imaging and myocardial perfusion examination.The abnormal rate of electrocardiogram was 47.5%;the abnormal rate of echocardiography was 20%;the abnormal rate of cardiac magnetic resonance was 52.5%.Of all the patients,10(25%)patients had focal myocardial fibrosis.Conclusion: The incidence of cardiac damage in immune-mediated myopathy is high.Compared with echocardiography,cardiac magnetic resonance imaging can provide histological information,such as myocardial focal fibrosis,in addition to accurately assessing cardiac morphology and function.It is of great significance for early diagnosis and prognosis assessment of cardiac injury.CMR could be used as a routine clinical screening method for heart damage of immune-mediated myopathy.Part Ⅱ Application of myocardial mapping quantitative technique in early detection of subclinical cardiac involvement in immune-mediated myopathyAims: Cardiac involvement in immune-mediated myopathy(IMM)often leads to a poor prognosis.Traditionally,cardiac magnetic resonance T2-weighted and delayed-enhanced sequences can detect focal edema,necrosis or fibrosis in the heart,but they have limited diagnostic value in diffuse heart injury in patients with myopathy.We aimed to investigate whether cardiac magnetic resonance(CMR)mapping quantitative techniques can detect subclinical heart injury in immune-mediated myopathy.Methods: A total of 40 patients with IMMs and twenty-five healthy controls were recruited into our study.Ten patients with focal LGE were excluded.All the patients were all evaluated with a medical history and laboratory examination.A comprehensive CMR examination was performed on all the subjects.Results: There was no significant difference in left ventricular volume between the healthy control group and the LGE(-)IMM group(p>0.05).Elevated myocardium T1 values,T2 values,and extracellular volume fractions(ECV)of the LV were evident in patients even without late gadolinium enhancement(LGE)(p<0.05).Conclusion: CMR mapping technique can detect early subclinical cardiac involvement in IMM.