Prognostic Impact of Biplane Vena Contracta Width in Patients with Atrial Functional Mitral Regurgitation
Kentaro Minami, Kimi Sato, Tomoko Machino-Ohtsuka, Taiji Okada, Tomohiro Kaneko, Naoki Hoshino, Yuki Izumi, Mitsuhiko Ota, Kaoruko Sengoku, Ryo Nishikawa, Nahoko Kato, Takahiro Sakamoto, Noriko Eguchi, Masaru Obokata, Maiko Senoo, Yoshihito Saijo, Masashi Amano, Yukio Sato, Yohei Ohno, Yukio Abe, Kojiro Morita, Takahisa Inaba, Yu Yamada, Naoto Kawamatsu, Masayoshi Yamamoto, Tomoko Ishizu, Nobuyuki KagiyamaAbstract
Background
The vena contracta width (VCW) in parasternal long axis view (PLAX-VCW) and effective regurgitant orifice area (EROA) may underestimate the mitral regurgitation (MR) severity because of the elliptical-shaped effective orifice in atrial functional MR (AFMR). We aimed to assess the association between the vena contracta width by biplane method (Bi-VCW) and clinical outcomes in patients with AFMR and to compare the discriminative ability of Bi- VCW with those of other quantitative/semiquantitative metrics.
Methods
This was a substudy of a multicentre registry of moderate or severe AFMR. The Bi-VCW was evaluated as the average of the apical two-chamber and four-chamber views. The primary outcome was a composite of all-cause mortality, heart failure hospitalization, and mitral valve interventions.
Results
Among 423 studied patients, the Bi-VCW was higher than PLAX-VCW (8.1 ± 2.4 vs. 4.8 ± 1.9 mm, p < 0.001); the guideline-recommended threshold of Bi-VCW of >8.0 mm stratified 48% as severe MR. The Bi-VCW showed the highest discriminatory performance of the primary outcome (area under the time-dependent receiver operating characteristic curve of 0.76) compared with the PLAX-VCW and EROA and revealed an optimal threshold of 7.9 mm (sensitivity, 76%; specificity, 65%). In the multivariable Cox proportional hazards model, Bi- VCW >8.0 mm was independently associated with a higher risk of the primary outcome (adjusted hazard ratio=2.97, 95% confidence interval: 2.04–4.32, p < 0.001).
Conclusions
The Bi-VCW was independently associated with poorer outcomes in patients with AFMR and demonstrated superiority over the guideline-recommended parameters. It could serve as an independent and first surrogate for risk stratification in patients with AFMR.