The Clinical Value Of Cardiovascular Magnetic Resonance With Late Gadolinium Enhancement In Patients With Dilated Cardiomyopathy

Purpose:Dilated cardiomyopathy(DCM)was defined as a cardiomyopathy with left ventricular or biventricular dilation and systolic dysfunction in the absence of serious coronary heart disease and abnormal load(uncontrolled hypertension,valvular heart disease or congenital heart disease).Dilated cardiomyopathy is the ultimate result of multiple etiologies,including multiple ventricular remodeling and clinical outcomes among patients.The current risk stratification is mainly based on the assessment of left ventricular ejection fraction(LVEF)and clinical symptoms,which is challenging,especially for the prediction of arrhythmia and sudden cardiac death.Many studies have found that myocardial fibrosis is an important pathophysiological process in the development of cardiomyopathy and is closely related to ventricular remodeling and poor prognosis.Cardiovascular magnetic resonance with late gadolinium enhancement(LGE-CMR)can be used to assess the myocardial fibrosis non-invasively with imaging of contrast agent Gd-DTPA(gadolinium diethylenetriamine penta-acetic acid)in myocardium.It has become an important diagnostic tool for various heart diseases with wide application prospect.The purpose of this study is to investigate the clinical value of cardiovascular magnetic resonance with late gadolinium enhancement in the evaluation of the structure and function of left ventricular system in patients with dilated cardiomyopathy.Methods:Select dilated cardiomyopathy patients in the First Affiliated Hospital of Dalian Medical University who underwent plain and enhanced cardiovascular magnetic resonance with GE Signa HDxt 3.0T MRI machine from 2016 to 2017.Based on the results of myocardial imaging,the patients can be divided into LGE positive(with late gadolinium enhancement imaging)group and LGE negative(without late gadolinium enhancement imaging)group,between which the clinical features were compared.Data were expressed as mean ± SD or as frequencies.Two-detailed paired and unpaired.Student t tests were used to study normally distributed data.?2 Test and Fisher Exact Test were delivered to compare non-continuous variables expressed as proportions.Probability values are significant when P<0.05.All the data was analyzed by SPSS 19.0 software.Results:31 cases of dilated cardiomyopathy patients with complete clinical data and cardiovascular magnetic resonance scan and enhanced examination were studied.Excluding 1 case of severe aortic valvular disease and 1 case with poor image,the remaining 29 patients met the inclusion criteria of this study.Among them there were 24 males(82.8%)and 5 females(17.2%).The age of all the patients ranged from 29 to 73 years,the average age was 55.6 ± 12.5 years.Among them there were 22 patients with idiopathic dilated cardiomyopathy(75.9%),4 patients with non-compaction of ventricular myocardium(13.8%),3 patients with alcoholic cardiomyopathy(10.3%).In 29 patients with progressive exacerbation of heart failure,9(31.0%)patients' cardiac function were Class II-III,20(69.0%)patients' cardiac function were Class III-IV,according to the NYHA(New York Heart Association)classification.All the patients in this study had hypokinesia of left ventricle,the range of their LVEF(left ventricular ejection fraction)was 18-44%.They were all found with relative valvular insufficiency,and mostly were mitral or tricuspid valvular insufficiency.In ultrasound examination,23 patients(79.3%)were found with dilated left ventricular system,5 patients(17.2%)showed dilation of whole heart.Of all patients,there were 17 patients(58.6%)with late gadolinium enhancement imaging,12 patients(41.4%)without that imaging.12 patients had the histories of SVT/NSVT(Sustained Ventricular Tachycardia/Nonsustained Ventricular Tachycardia),among which 8(47.1%)of them belonged to LGE positive group and 4(33.3%)belonged to LGE negative group.And there was no statistical difference between the two groups(p=0.703).LGE was present in 17 DCM patients,with midwall(14 patients,82.4%),patchy(2 patients,11.8%)and regional(1 patients,5.9%)subendocardial distribution patterns within the myocardium.The distribution segments of LGE showed in left ventricular wall included mid-wall(14 patients,82.4%),inferior wall(4 patients,23.5%),lateral wall(3 patients,17.6%),and apex(1 patient,5.9%).Perfusion defects also showed in 11 patients' CMR,including mid-wall(8 patients),lateral wall(8 patients)and inferior wall(4 patients),of which 4 patients had decreased subendocardial perfusion.At the same time LAEDD(left atrial end diastolic diameter),LVEDD(left ventricular end diastolic diameter),LVEDV(left ventricular end diastolic volume),LVESV(left ventricular end systolic volume),LVmass(left ventricular mass)and LVEF(left ventricular ejection fraction)were also compared between LGE positive group and LGE negtive group,but there were no statistical difference of them between the two groups.Conclusions:Midwall LGE within the myocardium is the significant feature of DCM,mostly with the distribution in ventricular septum.The proportion of the rest segments showed with LGE are basically the same,including the basal and mid segment.LGE seldom showed in apical segment.There is no significant difference of the structure and function of left ventricular system between LGE positive group and LGE negtive group.There maybe some dysfunction of micrangium in the development of myocardial fibrosis in DCM,which can affect the blood supply of local myocardium.So that LGE or perfusion defects can occur in local myocardium under CMR,even without coronary artery disease and related symptoms.