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 ≥ 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 < 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). CONCLUSIONS: 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.