Abstract 9566: Quantification of Valve Regurgitation in the Pediatric Population Using 3-Dimensional Echocardiography: Feasibility and Comparison With Cardiac Magnetic Resonance Imaging

Abstract

Introduction: Valvar regurgitation in pediatric patients is commonly assessed by cardiac magnetic resonance (CMR). This modality is associated with increased cost and need for anesthesia in young patients when compared to echocardiography. 3-dimensional echocardiography (3DE) can measure ventricular volumes and calculate the regurgitation fraction (RF) by comparison of stroke volumes - similar to CMR. Given the potential advantages of 3DE in children, this study sought to compare the quantification of single valvar regurgitation using 3DE versus CMR as the gold standard. Methods: Pediatric patients ≤18 years of age were included in the study. Patients were excluded if they had more than mild regurgitation of an additional valve, significant shunt, or suboptimal imaging windows. Full volume data sets were obtained sub-costally using a Philips IE33 or EPIQ CVx machine (X5 or X7 ultrasound probe). 3DE volumes were analyzed using 4D Cardioview (Tomtec Imaging Systems) and compared with ventricular volumes and RF obtained by CMR. Inter- and intra-observer reliability were assessed for 3DE ventricular volumes and RF. Results: 34 patients had volumes obtained by 3DE and CMR with two patients having pairs of studies performed on different dates. The median age was 8.7 (IQR; 3.9-12.3) years. 12 studies (33%) were obtained under sedation. Primary valve involvement was: mitral-12 (33%), tricuspid-9 (25%), pulmonary-1 (3%), and aortic-14 (39%). Agreement between 3DE and CMR ventricular volumes by intraclass correlation coefficient (ICC) was excellent (ICC>0.90). Agreement for the regurgitant fraction was good (ICC 0.80 (95% CI; 0.68, 0.88)). Ventricular volume ratios obtained by MRI and 3DE were strongly correlated; Spearman r = 0.92 (95% CI; 0.85-0.96). Inter-observer reliability was excellent for ventricular volumes and moderate for RF (ICC 0.63 (95% CI; 0.23, 0.85)). Intra-observer reliability was excellent for ventricular volumes and RF (ICC≥0.97). Conclusions: Assessment of single valvar regurgitation using 3DE compares favorably with CMR in pediatric patients. The shorter time for image acquisition and lower cost will allow for standard application of 3DE to measure single valve regurgitation in this population, particularly on a serial basis.