Abstract 17475: Predictors of Procedural Failure in High Risk Patients Undergoing Mitraclip Implantation for Mitral Regurgitation
Background and objective. In patients at high risk for surgery, MitraClip (MC) implantation is increasingly used to treat significant (≥ grade 3+) mitral regurgitation (MR). We sought to assess clinical and echocardiographic variables predictive of procedural outcome.
Methods and results. Between 09/2008 and 12/2011, 270 consecutive patients not amenable to surgery by heart team consensus (74 ± 9 years, 172 [64%] men, LV ejection fraction 44 ± 16%, logistic EuroSCORE 29 ± 19%) underwent MC therapy at our center. MR etiology was functional in 68%, degenerative in 22%, and mixed in 10% of patients. MR of grade 3+ and 4+ was present in 56 and 44% of patients, respectively. Overall procedural success - defined as residual MR severity of grade ≤ 2+ at discharge - was achieved in 240 procedures (89%), with a reduction in MR severity from grade 3+ (60%) or 4+ (40%) at baseline to grade 1+ (43%) or 2+ (57%) at discharge (P < 0.0001). No clip implantation was feasible in 11 patients and one or more clips were implanted during 259 procedures (1 clip in 167, >1 clip in 92 procedures). When patients were dichotomized by MR etiology (purely functional [FMR] vs. degenerative/mixed [DMR]), a significantly lower procedural success rate was noted in DMR patients (70/86 [81.4%] vs. 169/184 [91.8%] in FMR patients, P = 0.023). In univariate logistic regression analysis, MR 4+ at baseline (P = 0.0063), DMR etiology (P = 0.023), increased effective regurgitant orifice area (EROA) (P = 0.011), decreased mitral valve orifice area (MVA) (P = 0.035), and increased mean transmitral pressure gradient (P = 0.0008) were predictive of procedural failure. Only baseline MR severity grade 4+ (odds ratio 2.9 [95% CI, 1.02 - 8.24], P = 0.046) and MVA (odds ratio 0.95 [95% CI, 0.90 - 0.99], P = 0.037) remained as independent predictors of procedural failure in multivariate analysis.
Conclusions. The current data reveal that success of MitraClip therapy depends on sufficient mitral valve leaflet mobility in order to prevent relevant mitral stenosis. The fact that severe MR is also associated with an increased risk of procedural failure may suggest that MitraClip therapy is particularly effective when applied early in the course of the disease.
- © 2012 by American Heart Association, Inc.