Abstract 4695: PISA and Vena Contracta have Significant Inter-Observer Variability in the Assessment of Mitral Regurgitation, A Multicenter International Echocardiographic Study
Background: In mitral regurgitation (MR) quantitative parameters have prognostic value. Recommendations for MR evaluation stress the importance of quantification of the vena contracta width (VC) and effective regurgitant orifice area by proximal isovelocity surface area (PISA) measurement. Reliable and accurate assessment of MR is important for risk stratification and clinical decision making. We hypothesize that color Doppler based assessment may be particularly susceptible to inter-observer variability.
Methods: Echocardiograms of 16 patients with MR were selected for interpretation. Parasternal long axis and apical 4-chamber images with color Doppler were reviewed through secure web by 10 echocardiography specialists (ES) from the US, Israel and Japan. Participants in the study were asked to perform manual measurements VC, PISA and to grade MR severity (MRS) based on color Doppler data.
Results: There was moderate inter observer agreement for all three parameters, including VC width, PISA as well as MR grade. Reliability using intra class correlation coefficient for VC was 0.51 (95% CI: 0.29 to 0.78), for PISA - 0.65 (95% CI: 0.46 – 0.85) and for MRS - 0.52 (95% CI: 0.32– 0.76). There was only fair inter observer agreement for MR grade as severe vs. non-severe in the three parameters (Kappa for VC=0.37, PISA=0.41 and MRS=0.36) (Figure⇓).
Conclusion: VC and PISA quantification as well as MR grade based on color Doppler parameters are only modestly reliable and associated with substantial inter-observer variability.