Right Ventricular Longitudinal Strain Reproducibility Using Vendor-Dependent and Vendor-Independent Software

Background: Right ventricular peak systolic longitudinal strain (RVLS) has emerged as an approach for quantifying right ventricular function in diseases such as pulmonary hypertension and congenital heart disease. A major limitation in applying RVLS is that strain imaging and analysis are proprietary, which may result in systematic differences from vendor to vendor. The goal of this study was to test the reproducibility of right ventricular strain analysis among selected vendor-specific software (VSS) and vendor-independent software (VIS) on images obtained from different ultrasound scanners, as would be common in clinical practice or in a multicenter clinical trial. Methods: In this prospective, single-center study, 35 patients (5 healthy subjects and 30 with pulmonary hypertension) each underwent two echocardiographic scans, one using GE (Vivid E9) and the other using Philips (iE33) ultrasound systems. Images were analyzed using both VSS and VIS (TomTec) software for determination of RVLS. A repeated-measures analysis of variance was used to assess for any systematic differences among methods, as well as effects of scanner and software and a possible interaction between scanner and software for each strain measurement. Results: Differences for global strains were not statistically significant among VSS packages (P ≥.05), but some differences were noted between VSS and VIS. Wide variability between regional peak strain measurements was noted, but no systematic differences were found. Conclusions: Global RVLS values between VSS systems are not significantly different but may differ slightly from VIS. When comparing regional strain between VSS and VIS analyses, there is widespread variability without clear systematic differences.