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

## TL;DR

This study shows that vena contracta measurements are more accurate than traditional methods for identifying severe secondary mitral regurgitation using 3D transesophageal echocardiography.

## Contribution

The study introduces vena contracta-based parameters as a novel and more accurate method for assessing severe secondary mitral regurgitation.

## Key findings

- VCWAverage and VCAEllipse showed stronger correlations with VCA than EROAPISA.
- Over 40% of patients with moderate or less SMR by EROAPISA had severe SMR based on VCA.
- VCWAverage and VCAEllipse improved reclassification of SMR severity in patients with EROAPISA <0.30 cm².

## Abstract

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.

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 ≥0.39 cm2.

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
<0.30 cm2, 21 of 24 [87.5%] patients with
EROAPISA = 0.30–0.40 cm2, and 16 of 16 [100%] patients with
EROAPISA
≥0.40 cm2 [Cochran–Armitage test; p
<
0.001]). Among patients with EROAPISA
<0.30 cm2, SMR severity based
on VCA was accurately reclassified using VCWAverage (McNemar’s test;
p = 0.505) and VCAEllipse (p = 0.182).

Among patients who had SMR with EROAPISA of <0.30
cm2, suggestive of moderate or less SMR according to current guidelines,
>40% had discordantly severe SMR based on VCA. VCWAverage and
VCAEllipse values were useful for identifying severe SMR based on VCA in
these patients.