Sources of Variability in Vena Contracta Area Measurement for Tricuspid Regurgitation Severity Grading: Comparison of Technical Settings and Vendors

Abstract Background Previous studies found different cut-offs of vena contracta area (VCA) to define severe tricuspid regurgitation (TR). The aim of this study was to investigate the factors associated with such variability through comparing technical variables and vendors. Methods Sixty-nine patients with scheduled tricuspid surgery were included in this prospective study. For each patient, TR data sets were obtained through three-dimensional (3D) color Doppler transthoracic echocardiography on at least two of the three systems: GE Vivid E95 (n=39), Siemens SC2000 prime (n=64) and Philips EPIQ 7C (n=60). The VCA was measured with default settings or with color baseline shifted on all three platforms, and with minimal color gain (10% to 20%) on GE. Results Color gain reduction and baseline shift caused significant change in VCA measurement ( -46% and 10% respectively). Inter-vendor comparison exhibited wide limits of agreement (the narrowest range, -74% to 167%), either with default or optimized settings. Different technical settings, platforms and reference methods all found different VCA cut-offs for severe TR. Conclusions VCA measurement in TR is sensitive to technical factors and demonstrates inter-vendor variability. Technical variables in VCA measurement should be reported in detail for future research comparison. Same vendor and settings should be used for longitudinal analysis of TR VCA in the same patient in multi-vendor echocardiographic labs.