Comparison of Strain-Encoding and Feature-Tracking Derived Myocardial Deformation Assessment of Left Ventricular Function in a Pediatric and Adult Congenital Heart Disease Cohort.

BACKGROUND: Cardiac magnetic resonance (CMR) strain can be assessed with feature-tracking (FT), which utilizes a post-processing algorithm to quantify myocardial deformation on routine cine images, and strain-encoding magnetic resonance imaging (SENC), which uses parallel magnetization tags combined with out-of-plane phase-encoding gradients to quantify deformation. Assessing agreement is critical to determine whether results can be translated between methods. We compared SENC to FT in the assessment of left ventricle (LV) global longitudinal strain (GLS) and global circumferential strain (GCS) in a cohort of pediatric and adult congenital heart disease (ACHD) patients. METHODS: Pediatric subjects and ACHD patients underwent CMR on 1.5 T Siemens scanners, including balanced steady-state-free precession (bSSFP) cine imaging and SENC acquisitions in apical two and four chamber, left ventricular outflow tract, and short axis views. bSSFP cine imaging FT analysis was completed with Medis QStrain. Myocardial Solutions MyoStrain was used to analyze SENC. Correlation was assessed by Spearman's rank correlation coefficient. Agreement between techniques was assessed with concordance correlation coefficient (CCC) and Bland-Altman. RESULTS: The cohort included 134 patients, 75 with congenital heart disease (56%). The median age was 16.3 years (IQR 13.7, 19.5). Median LV ejection fraction was 57% (IQR 54.4, 61.6). SENC and FT were in poor agreement for GLS (Spearman's ρ = 0.58, p < 0.001; CCC 0.24) and GCS (Spearman's ρ = 0.29, p < 0.001; CCC 0.03). CONCLUSION: There was poor agreement between SENC and FT derived GLS and GCS in a cohort of pediatric and ACHD patients, suggesting that SENC and FT cannot be used interchangeably.

Smartphone interfaced handheld echocardiography for focused assessment of ventricular function and structure in children: A pilot study.

INTRODUCTION: Miniaturized echocardiographic machines improve availability and portability and can be particularly useful for underserved and resource-limited settings. The goal of this study was to compare left ventricular fractional shortening (FS) and left ventricular ejection fraction (LVEF) obtained by a newer handheld echo (HHE) machine to standard transthoracic echocardiogram (TTE) in children. METHODS: Pediatric outpatients (Birth-18 years) undergoing TTE were prospectively enrolled. HHE protocol included 2D and M-mode images from the parasternal long, short, and apical-4 chamber views. HHE and TTE measurements were reviewed for agreement. Kappa statistic was used to analyze qualitative indices while FS and LVEF were analyzed with Lin's concordance correlation coefficient (CCC) and Bland-Altman limits of agreement (loa). RESULTS: Sixty children were enrolled; 55 were included in the quantitative analysis. Mean age was 7.5 ± 5.5 years; 67% males; median HHE image acquisition duration was 2.3(1-5) minutes. Fractional shortening and EF by HHE showed good agreement with TTE [CCC = 0.82, 95%CI (0.73,0.90), mean bias -3.18%, loa (-7.00,6.44%) vs CCC = 0.81 (0.72,0.90), mean bias -0.87%, loa (-6.94,5.17%], respectively. In children ≤5 years, HHE FS (n = 20) and EF (n = 21) agreed with TTE measurement [0.59 (0.31, 0.88), mean bias 0.30%, loa (-8.5, 9.1%); 0.79 (0.63, 0.96), mean bias 0.10%, loa (-5.99, 6.14)]. Kappa values for RV size, function, and LV function were 1.00 (P < .05); 0.75 for LV size (P < .05) and 0.66 for pericardial effusion (P < .05). CONCLUSION: Handheld echo demonstrates good correlation with standard TTE for focused assessment of ventricular chamber sizes and function in children.