1355477 - Comparative Analysis of Myocardial Strain Measurement by Cardiac Magnetic Resonance Imaging and Echocardiography in Children with Heart Disease

Accurate assessment of left ventricular systolic function remains a challenge, especially in the pediatric population with congenital heart disease (CHD) ^1,2. Cardiac magnetic resonance imaging (CMR) and echocardiogram are commonly used in pediatric patients with suspected cardiac dysfunction to evaluate and follow up on systolic and diastolic dysfunction. Myocardial deformation (strain and strain-rate) analysis is a proven non-invasive method to objectively assess degree of LV dysfunction^3,4. Speckle tracking echocardiography (STE) and Feature tracking CMR (FT-CMR) are the two commonly used technique for myocardial deformation analysis. However, there is paucity of data on comparison of myocardial deformation analysis using FT-CMR and STE in pediatric patients with various CHD. Echocardiogram is a low cost, non-invasive and widely available modality. However, myocardial deformation analysis by STE may be compromised by suboptimal image quality due to insufficient acoustic windows. CMR provides superior spatial resolution with sharp contrast between blood and myocardium. However, CMR is costly, limited by availability and time-consuming study which quite often require general anesthesia in children. We hypothesize, global myocardial strain values on STE can be used interchangeably and synergistically with FT-CMR in the management of children with CHD.

Methods:

Retrospective chart review was performed on children who underwent CMR over a 3-year period. Patients aged under 18 years with CMR and echocardiogram performed less than 6 months apart were included in the study. Patients with single ventricle anatomy were excluded. Global longitudinal strain (GLS) by FT-CMR was measured from 2-chamber, 3-chamber and 4 chamber views using Medis Suite MR 2.0 software (Fig.1). All statistical analysis was performed on IBM SPSS 27 statistical software. Agreement between FT-CMR and STE myocardial strain (Fig.2) was assessed using Bland-Altman analysis.

Results:

One-hundred-six patients (N = 106) were identified with CMR and echocardiograms performed. The FT-CMR and STE measurements were available for all these patients. The median (IQR) age in years was 13 (7,15) and male to female ratio was 61:39. The median age (years), height (cm), weight (kg) and BSA were 13 (7,15), 157 (125, 165), 51(27,68) and 1.50 (0.99,1.75) respectively. The mean GLS by FT-CMR was -18.106 (±3.96) and by STE was -18.692 (±2.79). The Bland-Altman analysis for strain by FT-CMR and STE (Fig.3) produced a systematic bias (mean difference) of 0.6 and the 95% limits of agreement were –8.76 to +9.94. The precision error was only 0.26%.

Conclusion:

In our study there was good agreement between FT-CMR and STE with small systematic bias. Consequently, FT-CMR and STE can be used interchangeably and synergistically for myocardial strain evaluation in children with CHD. Further prospective studies with large sample size are needed to assess the degree of agreement between FT-CMR and STE, especially in single ventricle patients.