Predictors and Clinical Impact of Functional Mitral Stenosis Induced by Restrictive Annuloplasty for Ischemic and Functional Mitral Regurgitation

• Published in: Circulation Journal Vol. 81; no. 12; pp. 1832 - 1838
• Main Authors: Kainuma, Satoshi, Taniguchi, Kazuhiro, Toda, Koichi, Funatsu, Toshihiro, Kondoh, Haruhiko, Miyagawa, Shigeru, Yoshikawa, Yasushi, Hata, Hiroki, Saito, Shunsuke, Ueno, Takayoshi, Kuratani, Toru, Daimon, Takashi, Masai, Takafumi, Sawa, Yoshiki, Osaka Cardiovascular Surgery Research (OSCAR) Group
• Format: Journal Article
• Language: English
• Published: Japan The Japanese Circulation Society 2017
• Subjects: Advanced cardiomyopathy; Functional mitral regurgitation; Functional mitral stenosis; Restrictive mitral annuloplasty; Functional mitral regurgitation; Restrictive mitral annuloplasty; Functional mitral stenosis; Advanced cardiomyopathy
• ISSN: 1346-9843; 1347-4820
• DOI: 10.1253/circj.CJ-17-0060

Background:There are few reports of the determinants of “functional” mitral stenosis in terms of a residual mitral valve (MV) pressure gradient >5 mmHg following restrictive mitral annuloplasty (RMA) or the effect on long-term outcome in patients with functional mitral regurgitation (MR).Methods and Results:Serial cardiac catheterization and echocardiographic studies were performed in 55 patients with functional MR who underwent RMA using a 24/26-mm semi-rigid complete ring. The mean postoperative (1 month) catheter-measured MV gradient was 3.4±1.6 mmHg, which was independently associated with corresponding cardiac output [standardized partial regression coefficient (SPRC)=0.59] and indexed effective orifice area (SPRC=−0.25). Body surface area (BSA) had the greatest contribution to MV gradient (SPRC=0.38), followed by use of a 24-mm ring (SPRC=0.33) and hemodialysis (SPRC=0.26). Receiver-operating characteristic curve analysis demonstrated an optimal BSA cutoff value of 1.86 m2to predict post-MV stenosis (21% for <1.86 m2vs. 86% for ≥1.86 m2, P=0.002). During follow-up (75±32 months), freedom from adverse events did not differ between patients with (n=16) and without (n=39) an MV gradient ≥5 mmHg (log-rank P=0.24).Conclusions:Post-RMA MV gradient was determined not only by the degree of annular reduction but also by patients’ hemodynamic factors (e.g., cardiac output). Implantation of a 24/26-mm annuloplasty ring for patients with BSA ≥1.86 m2indicated a high likelihood of post-MV stenosis. However, mild MV stenosis did not adversely affect late outcome after RMA.