Evaluation Of Right Ventricular Myocardial Deformation In Patients With Stable Chronic Obstructive Pulmonary Disease By Cardiovascular Magnetic Resonance Feature Tracking: A Clinical Study

Objective:To explore and assess myocardial deformation of right ventricular with chronic obstructive pulmonary disease(COPD)patients in the stable period using cardiac magnetic resonance imaging feature tracking(CMR-FT),and the correlation of strain parameters and clinical indexes.To discuss feasibility and accuracy of CMR-FT in evaluating right ventricular strain in patients with stable COPD,and reveal its application value in clinical.Materials and methods:Twenty-three stable COPD patients(19 male and 4 female,49-76 years old,mean age 63.65±9.01 years)confirmed by clinic in Affiliated Zhongshan Hospital of Dalian University were enrolled in this study from October 2016to September 2017.Twenty healthy volunteers(16 male and 4 female,40-77 years old,mean age 58.90±12.43 years)were matched with the COPD patients for demographics including age,sex,and body-mass index.All participants undergone 1.5T conventional CMR scan.N-terminal pro-brain natriuretic peptide(NT-proBNP)and the ratio of the forced expiratory volume in 1 sec to the forced vital capacity(FEV1/FVC)must be acquired within 48 hours with the scan.After the scan,two skilled cardiac post-processing radiologists respectively in double blind measured biventricular structure and function parameters and right ventricular stain parameters by CVI42. Independent sample t-test were used to compare differences of biventricular CMR data between stable COPD patients and healthy controls.Pearson and Spearman correlation analysis were used for the correlation between right ventricular strain parameters and clinical indexes.P values less than 0.05 were considered to be statistically significant.Results:1.Biventricular structure and function parameters:The right ventricular mass index of stable COPD was significantly higher than in the healthy controls(25.70±8.51 g/m~2vs20.45±4.44 g/m~2,p=0.014).No differences in other parameters between two groups.2.Right ventricular stain parameters:The right ventricular global longitudinal strain,right ventricular diastolic longitudinal strain rate(RV DLSR),right ventricular diastolic circumferential strain rate and right ventricular longitudinal displacement of stable COPD was significantly higher than in the healthy controls.3.Correlations between right ventricular strain parameters and clinical indexes:RV DLSR was negatively correlated with NT-proBNP(r=-0.530,p=0.009)and FEV1/FVC(r=-0.476,p=0.022).Conclusion:1.The feasibility and repeatability of CMR-FT in assessing right ventricular myocardial deformation with stable COPD patients were high.CMR-FT could reflect the change of myocardial deformation of patients,and had important value in early and accurate assessment of cardiac function changes and individualized treatment.2.Right ventricular strain parameters were abnormal even in the stable patients with normal right ventricular structure and function parameters,and its diastolic function was earlier than systolic function changes.3.There was clear correlation between right ventricular strain in stable COPD patients and the clinical indexes.If right ventricular strain of COPD patients was decrease while right ventricular structure and function parameters were normal,clinic should pay attention to the COPD patients with possibility of clinical deterioration.