Left Ventricular Strain Analysis by Tissue Tracking- Cardiac Magnetic Resonance for early detection of Cardiac Dysfunction in children with End-Stage Renal Disease

Background: Cardiovascular disease is a major cause of morbidity and mortality in end-stage renal disease (ESRD). Reduction in left ventricular ejection fraction (LVEF) represents late left ventricle (LV) dysfunction. Cardiac MRI myocardial strain analysis is an alternative method for assessment of LV function. Purpose: To investigate whether LV strain analysis is more sensitive than LVEF for early detection of systolic dysfunction in children with ESRD. Study type: Case control. Population: Thirty-two children with ESRD (median 14 years, 17 females) and 10 healthy control (median 12.5 years, 7 females). Field Strength and Sequences: A 1.5 T /retrospective ECG-gated steady-state free precession (SSFP). Assessment: LVEF, and indexed LV mass (LVMi) and LV end-diastolic volume (LVEDVi) were measured. Using tissue tracking analysis, LV endocardial and epicardial contours were traced in short and long axes at end diastole to calculate global longitudinal (GLS), circumferential (GCS) and radial (GRS) strains. Statistical Analysis: Cardiac MRI and strain parameters were compared between patients and control, and between subgroup with preserved LVEF and control by Student t-test/Mann Whitney test. Diagnostic accuracy was assessed by Receiver operating characteristic analysis. Strain as predictor of poor outcome (mortality, pulmonary edema, and/or heart failure) within 1-year follow up was investigated by binary logistic regression. Results: Compared to control, cardiac MRI LVEF, LVEDVi, LVMi, GLS, GCS and GRS were significantly impaired in patients. Patients with preserved LVEF had significantly higher LVEDVi, LVMi and significantly impaired GCS and GRS than control. Strain parameters were significantly correlated with LVEF, LVEDVi, and LVMi. GCS and GRS demonstrated greater diagnostic accuracy than GLS (area under curve: 0.89). LVEF, LVMi, GCS, and GRS were correlated with poor outcome. Conclusion: Cardiac MRI tissue tracking could identify subclinical LV dysfunction in children with ESRD and still preserved LVEF. Furthermore, LV strain parameters (GCS and GRS) were correlated with future cardiovascular events. Evidence Level: 2. Technical Efficacy: Stage 2.