One-year Outcomes and Predictors of Mortality After MitraClip Therapy in Contemporary Clinical Practice: Results From the German Transcatheter Mitral Valve Interventions Registry

Miriam Puls; Edith Lubos; Peter Boekstegers; Ralph Stephan von Bardeleben; Taoufik Ouarrak; Christian Butter; Christine S. Zuern; Raffi Bekeredjian; Horst Sievert; Georg Nickenig; Holger Eggebrecht; Jochen Senges; Wolfgang Schillinger

Disclosures

Eur Heart J. 2016;37(8):703-712. 

In This Article

Methods

Transcatheter Mitral Valve Interventions Registry

The non-randomized TRAMI registry (also named German mitral valve registry) was established in 2010 in order to assess safety and efficacy of catheter-based mitral valve interventional techniques (both for stenosis and regurgitation) and was made available to all sites in Germany performing such therapies. The vast majority of patients enrolled in TRAMI underwent MitraClip® implantation. Detailed descriptions of the registry and initial results have recently been published.[9,12–17] The registry was organized into a prospective and a retrospective section. Prospective patient enrolment began in August 2010 and ended in July 2013. Follow-up for the prospective section is performed centrally by the 'Institut für Herzinfarktforschung (IHF)' at the Heart Center Ludwigshafen at 30 days and at 1, 3 and 5 years. One-year follow-up data were collected until July 2014 by standardized telephone interview. Participating centres were also encouraged to enter retrospectively all patients treated with MitraClip between January 2009 and July 2010 and perform follow-up visits according to institutional practice. These patients were not included in the study due to lack of standardized follow-up and lower data quality. The following analyses rely exclusively on patients who were prospectively enrolled into TRAMI and who were available for 1-year follow-up. All patients gave written informed consent. Data were collected via web-based electronic case report forms by the IHF Ludwigshafen. Importantly, the TRAMI registry is independent from industry. The majority of funding was provided by proprietary means of the IHF and additional funding by 'Deutsche Herzstiftung e.V.'

Assessment of Mitral Regurgitation, Device, and Procedure

The severity of MR was graded in three grades as I (mild), II (moderate), and III (severe) based on current recommendations[18] and was evaluated at each individual centre. The MitraClip system, a polyester-covered cobalt-chromium V-shaped device with two movable arms, received CE Mark in 2008. The implantation procedure was performed as previously described.[6,7,19]

Definitions

In the TRAMI registry, procedural failure was defined as severe residual MR, abortion of MitraClip procedure, conversion to open heart surgery, or failure as assessed by the interventional team: In addition to the criteria mentioned first, the operator could classify an intervention as unsuccessful due to subjective reasons (i.e. non-significant MR reduction). Major adverse cardiac and cerebrovascular events (MACCE) included death from any cause, stroke, and myocardial infarction.

Quality of Life

For evaluation of health-related quality of life, the EQ-5D-3L,[20,21] one of the most common generic questionnaires was used. It essentially comprises two sections. The EQ-5D descriptive system consists of five dimensions (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression) each of which can take one of three responses recording three levels of severity (no problems/some or moderate problems/extreme problems). The EQ visual analogue scale (EQ VAS) records the respondent's self-rated health on a vertical scale where the endpoints are labelled 'Best imaginable health state, 100' and 'Worst imaginable health state, 0'. This information can be used as a quantitative measure of health outcome as judged by the individual respondents.

Statistical Analysis

Categorical variables are presented by absolute numbers and percentages and are compared by χ 2 test. Continuous variables are expressed as means with standard deviations or medians with interquartile ranges and are compared by Mann–Whitney–Wilcoxon test. The cumulative one-year incidence of mortality and MACCE was estimated by the Kaplan–Meier method.

Multivariable Cox regression using stepwise forward selection was performed to analyse the influence of relevant variables on 1-year mortality. We included all variables correlated with 1-year mortality at P < 0.1 or expected to influence outcome from previous publications. To avoid collinearity, the surgical risk scores (log. EuroSCORE and STS Score) were excluded, because some of their components were inserted into the model.

The change within the EuroQoL five dimensions and EQ-5D score between baseline and 1-year FU was tested using the Sign test.

All tests were two tailed and P-values <0.05 were considered significant. SAS statistical package version 9.3 (Cary, NC, USA) was used for the computations.

processing....