One-year outcomes and predictors of mortality after MitraClip therapy in contemporary clinical practice: results from the German transcatheter mitral valve interventions registry

AIMS: The transcatheter mitral valve interventions (TRAMI) registry was established in order to assess safety and efficacy of catheter-based mitral valve interventional techniques in Germany, and prospectively enrolled 828 MitraClip patients (median age 76 years, median log. EuroSCORE I 20.0%) between August 2010 and July 2013. We present the 1-year outcome in this MitraClip cohort-which is the largest published to date.

METHODS AND RESULTS: Seven forty-nine patients (90.5%) were available for 1-year follow-up and included in the following analyses. Mortality, major adverse cardiovascular event rates, and New York Heart Association (NYHA) classes were recorded. Predictors of 1-year mortality were identified by multivariate analysis using a Cox regression model with stepwise forward selection. The 1-year mortality was 20.3%. At 1 year, 63.3% of TRAMI patients pertained to NYHA functional classes I or II (compared with 11.0% at baseline), and self-rated health status (on EuroQuol visual analogue scale) also improved significantly by 10 points. Importantly, a significant proportion of patients regained the complete independence in self-care after MitraClip implantation (independence in 74.0 vs. 58.6% at baseline, P = 0.005). Predictors of 1-year mortality were NYHA class IV (hazard ratio, HR 1.62, P = 0.02), anaemia (HR 2.44, P = 0.02), previous aortic valve intervention (HR 2.12, P = 0.002), serum creatinine ≥1.5 mg/dL (HR 1.77, P = 0.002), peripheral artery disease (HR 2.12, P = 0.0003), left ventricular ejection fraction <30% (HR 1.58, P = 0.01), severe tricuspid regurgitation (HR 1.84, P = 0.003), and procedural failure (defined as operator-reported failure, conversion to surgery, failure of clip placement, or residual post-procedural severe mitral regurgitation) (HR 4.36, P < 0.0001).

CONCLUSIONS: Treatment of significant MR with MitraClip resulted in significant clinical improvements in a high proportion of TRAMI patients after 12 months. In the TRAMI cohort, the failure of procedural success exhibited the highest hazard ratio concerning the prediction of 1-year mortality.