Usefulness of Vena Contracta for Identifying Severe Secondary Mitral Regurgitation: A Three-Dimensional Transesophageal Echocardiography Study

Abstract

Background: In secondary mitral regurgitation (SMR), effective regurgitant orifice area by the proximal isovelocity surface area method (EROAPISA) evaluation might cause an underestimation of regurgitant orifice area because of its ellipticity compared with vena contracta area (VCA). We aimed to reassess the SMR severity using VCA-related parameters and EROAPISA. Methods: The three-dimensional transesophageal echocardiography data of 128 patients with SMR were retrospectively analyzed; the following parameters were evaluated: EROAPISA, anteroposterior and mediolateral vena contracta widths (VCWs) of VCA (i.e., VCWAP and VCWML), VCWAverage calculated as (VCWAP + VCWML)/2, and VCAEllipse calculated as π × (VCWAP/2) × (VCWML/2). Severe SMR was defined as VCA ≥0.39 cm2. Results: The mean age of the patients was 77.0 ± 8.9 years, and 78 (60.9%) were males. Compared with EROAPISA (r = 0.801), VCWAverage (r = 0.940) and VCAEllipse (r = 0.980) were strongly correlated with VCA. On receiver-operating characteristic curve analysis, VCWAverage and VCAEllipse had C-statistics of 0.981 (95% confidence interval [CI], 0.963–1.000) and 0.985 (95% CI, 0.970–1.000), respectively; these were significantly higher than 0.910 (95% CI, 0.859–0.961) in EROAPISA (p = 0.007 and p = 0.003, respectively). The best cutoff values for severe SMR of VCWAverage and VCAEllipse were 0.78 cm and 0.42 cm2, respectively. The prevalence of severe SMR significantly increased with an increase in EROAPISA (38 of 88 [43.2%] patients with EROAPISA 40% had discordantly severe SMR based on VCA. VCWAverage and VCAEllipse values were useful for identifying severe SMR based on VCA in these patients.

Keywords

• secondary mitral regurgitation
• vena contracta width
• vena contracta area
• effective regurgitant orifice area