Concordance and Discordance of Echocardiographic Parameters Recommended for Assessing the Severity of Mitral Regurgitation.

Background: The American College of Cardiology/American Heart Association and American Society of Echocardiography guidelines recommend assessing several echocardiographic parameters when evaluating mitral regurgitation (MR) severity. These parameters can be discordant, making the assessment of MR challenging. The degree to which echocardiographic parameters of MR severity are concordant is not well studied.

Methods: We enrolled 159 patients in a prospective multicenter study. Eight parameters were included in this analysis: proximal isovelocity surface area (PISA)-derived regurgitant volume, PISA-derived effective regurgitant orifice area, vena contracta, color Doppler jet/left atrial area, left atrial volume index, left ventricular end-diastolic volume index, peak E wave, and the presence of pulmonary vein systolic reversal. Each echocardiographic parameter was determined to represent severe or nonsevere MR according to the American Society of Echocardiography guidelines. A concordance score was calculated as [Formula: see text] so that a higher score reflects greater concordance. There was no discordance when all the echocardiographic parameters agreed and high discordance when 3 or 4 parameters were discordant.

Results: The mean concordance score was 75±14% for the entire cohort. There were 9 (6%) patients with complete agreement of all parameters and 61 (38%) with high discordance. There was greater discordance in patients with severe MR but no difference between primary versus secondary or central versus eccentric jets. There was an improvement in concordance when only considering PISA-based regurgitant volume, PISA-based effective regurgitant orifice area, and vena contracta with agreement in 68% of patients.

Conclusions: There was limited concordance between the echocardiographic parameters of MR severity, and the discordance was worse with more severe MR. Concordance improved when considering only 3 quantitative measures of vena contracta and PISA-based effective regurgitant orifice area and regurgitant volume. These findings highlight the challenges facing echocardiographers when assessing the severity of MR and emphasize the difficulty of using an integrated approach that incorporates multiple components. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04038879.