Color Doppler Splay in Mitral Regurgitation: Hemodynamic Correlates and Outcomes in a Clinical Cohort

Background: Recently, an artifactual horizontal extension of the color Doppler signal was described in patients with mitral regurgitation (MR), called color Doppler splay (CDS). This side-lobe artifact was shown to be associated with concealed and significant MR. In the present study, the authors assessed the prognostic significance of CDS and its hemodynamic correlates.

Methods: Consecutive patients with primary and secondary MR underwent comprehensive transthoracic echocardiography. Machine settings were fixed for all patients. MR severity was assessed using an integrated approach, as advocated in current international guidelines. The presence of CDS and CDS width and duration were assessed. The outcome measures included the incidence of major adverse cardiac events (a composite of cardiovascular mortality, hospitalization for decompensated heart failure, mitral valve surgery, or percutaneous mitral intervention).

Results: One hundred twenty-seven of 469 patients (27%) with MR demonstrated CDS. The presence of CDS was associated with worse MR, and CDS width correlated with effective regurgitant orifice area, regurgitant volume, and vena contracta width. Mitral annular or leaflet calcification was inversely associated with the presence of CDS. Patients with CDS experienced worse event-free survival. For CDS width, a cutoff of >29 mm was identified as optimal regarding outcome prediction in our cohort and termed "severe CDS." In multivariate Cox regression, the presence of severe CDS was associated with adverse outcome, independent of MR etiology or severity and other clinical and echocardiographic predictors of outcome, and provided incremental prognostic value on top of these parameters.

Conclusions: In patients with MR, the presence of CDS is associated with more severe MR and worse outcomes. Severe CDS provides incremental prognostic value on top of traditional MR metrics and should alert the echocardiographer that MR severity may be underestimated.