Magnetic Resonance Imaging Characteristics And Related Prognosis Of End-stage Hypertrophic Cardiomyopathy

Part I Diagnostic and prognostic value of CMR for end-stage hypertrophic cardiomyopathyObjectivesEnd-stage phase of hypertrophic cardiomyopathy(ES-HCM)is a recognized part of HCM disease spectrum.Information on cardiac magnetic resonance(CMR)studies for ES-HCM especially for those without ventricular remodeling has been limited.We aimed to evaluate the morpho-functional and tissue features of ES-HCM with or without ventricular remodeling and to explore CMR prognostic value in these patients.MethodsWe analysed CMR scans of sixty-three ES-HCM patients and divided them into those with ventricular dilatation(D-ES,n=41)and those with normal ventricular size(N-ES,n=22).Cox proportional hazards models were used to assess the association between CMR parameters and outcomes.ResultsPatients in D-ES showed hypokinetic-dilated HCM phenotype,while patients in N-ES showed hypokinetic-restrictive HCM phenotype.LGE extent was significantly larger in D-ES(34.7%±15.4%vs.22.8%±7.7%;P<0.01).Atrial fibrillation and edema of lower extremity were more common in N-ES(72.7%vs.29.3%and 54.5%vs.24.4%,respectively;P<0.05).Log-rank test found no significant difference between 2 groups in combined end point of cardiovascular events(?2=0.66,P=0.418).In multivariate analysis,LGE(HR:1.57-1.83 per 10%LGE increase,P<0.01)and indexed left atrial volume(LAVI)(HR:1.14-1.21 per 20 mL/m2 increase,P<0.05)remained independently associated with combined end point when adjusted by other risk factors.ConclusionsThe CMR features of HCM in end-stage span between two extremes.LGE is more extensive in those with ventricular remodeling and LAVI is larger in those with normal ventricular size.Both LGE and LAVI are significant predictors of poor outcomes.Part ? Prognostic assessment of LGE derived texture features in end-stage hypertrophic cardiomyopathy patientsObjectivesLate gadolinium enhancement derived from cardiac magnetic resonance(CMR-LGE)is an accurate and noninvasive method to detect myocardium fibrosis.LGE may play an important role in risk stratification and prognostic evaluation of HCM.However,in previous studies,investigators only evaluated LGE by positive/negative or by LGE extent(LGE mass/myocardial mass).The structural arrangement difference between pixel point within LGE area is not defined.Medical image texture contains important information about the structural arrangement of surfaces and their relationship to the surrounding environment which are often invisible to the naked eye.The texture characteristics of LGE image have not been studied.But texture analysis is potentially applicable to all diseases.Therefore,we hypothesize that texture analysis will find some characteristics of LGE to predict patients' outcome.End-stage hypertrophic cardiomyopathy(ES-HCM)can potentially work as a good and easy platform to assess LGE texture features and correlate them to patients' outcome.Thus,the aim is to evaluate the prognostic value of texture features based on LGE-CMR images in ES-HCM.Methods67 ES-HCM patients(41 male and 26 female,mean age±standard deviation,46.20 years±13.38)were enrolled.All patients underwent 1.5 T CMR cine and LGE imaging.All patients were followed-up.The end point was the composite of cardiovascular death(cardiac death due to progression of heart failure or sudden cardiac death),aborted sudden cardiac death,heart transplantation and unscheduled heart failure hospitalization.Texture features were extracted from LGE images.Cox proportional hazard analysis and Kaplan-Meier analysis were used to determine the association of texture features and traditional parameters with event free survival.ResultsFamily history(hazard ratio[HR]=2.558,95%confidence interval[CI]?1.060-6.180),NYHA ?-?(HR=5.627,CI=1.652-19.173),left ventricular ejection fraction(HR=0.945,CI=0.902-0.991),left ventricular end-diastolic volume index(HR=1.006,CI=1.000-1.012)5 LGE extent(HR=1.911,CI=1.348-2.709)and three texture parameters[X0_H_skewness(HR=0.783,CI=0.691-0,889),XO_GLCM_cluster_tendency(HR=0.735,CI=0.616-0.877)and XO_GLRLM_energy(HR=1.344,CI=1.173-1.540)]were significantly associated with event free survival in univariate analysis(p<0.05).X0_H_skewness(HR=0.835,CI=0.723-0.965,p=0.015)and XO GLCM cluster tendency(HR=0.762,CI= 0.629-0.924,p=0.006)were remained significant when adjusted by LGE,respectively,but not for XO GLRLM energy(HR=1.344,CI=0.985-1.415,p=0.072).The optimum point of LGE,X0_H_skewness,XO GLCM cluster tendency and XO GLRLM energy were selected by ROC.Patients were divided into two groups by the four parameters,respectively.There were significant differences between each two groups in event free survival rate.ConclusionIncreased LGE heterogeneity(higher XO_GLRLM_energy,lower X0_H_skewness and lower XO GLCM cluster tendency)was associated with adverse events in ES-HCM patients.