Ventricular ContractiLe reserve for the optImization of Patient SELECTion for MitraClip implantation. (CLIP SELECT-study)

Patient selection is of high importance to ensure an effective MitraClip
implantation. Factors such as Left and Right Ventricular Function (respectively
LVF and RVF) and specifically ventricular contractile reserve, will influence
this efficacy. In case of a poor cardiac function with no contractile reserve,
a patient might not benefit as much as in case of a present contractile
reserve.
It may thus be a better strategy to treat a patient in time, before the
ventricles have deteriorated beyond repair, than to continue medical therapy
only. Likewise, it could be that in case of absent contractile reserve a
patient will not benefit sufficiently from MitraClip therapy.
Therefore, further knowledge of the contractile reserve of the Left Ventricle
(LV) and Right Ventricle (RV) in patients referred for mitral valve therapy is
useful to optimize patient and treatment selection. Dobutamine Stress
Echocardiography (DSE) is a qualitatively good and applicable modality for this
purpose and it provides useful information on the dynamic character of the
mitral regurgitation.
Apart from cardiac factors, comorbidities are determinants of patient outcome,
and will thus influence the efficacy of MitraClip treatment. Before acceptance
for MitraClip therapy according to guidelines, a life expectancy of at least
one year is required, which is often determined by comorbidity. But which
factors, and to which extent these factors play a role, is not yet known. To
gain insight into these factors will allow better patient selection in the
future. The MitraClip implantation will be more effective and less patients are
unnecessarily exposed to the risks of such a procedure.

Primary Objective: The association between the functional improvement (change
in VO2 max) and DSE parameters will be determined. In this way the diagnostic
characteristics of DSE will be investigated.

Secondary Objective(s): The influence of the MitraClip implantation on several
parameters is analyzed. The influence of the MitraClip on the contractile
reserve capacity, change in ejection fraction and change in MR when during DSE
will be analyzed. Also, the influence of the MitraClip on the Tricuspid valve
Regurgitation (TR) and on the pulmonary pressures will be analyzed.
Furthermore, heart failure markers are tracked, such as NT-proBNP, as this has
been shown to be predictive of outcomes after MitraClip implantations. The
influence the MitraClip on acute hemodynamic effects will be investigated with
help of pressure-volume loops. Finally, the role of co-morbidity factors on
long-term outcome after MitraClip implantation will be investigated.

With more knowledge of these influences, a more considered patient-specific
choice regarding the Mitraclip implementation can be made.

The study design is an observational cohort study. The duration of the patient
inclusion is from April 2015 and April 2017. The duration of the follow-up will
continue till April 2019

The procedures that have been added to the standard clinical care for research
purpose are attempt to be combined with standard appointment to minimize extra
hospital visits. Patient will undergo a CPET and a DSE during standard visits.
It is intended that these investigations are combined with the standard visits
for the screening and the standard MRI. The subject should fill in
questionnaires during standard visits. The conductance catheter will be
introduced through the sheath which is already introduced for the standard
blood pressure measurements. A 8 French sheath must be introduced instead of
the standard used 6 French sheath. The Swan-Ganz catheter will be introduced
through an extra introduced venous sheath on the left. As a result of the
measurements, the fluoroscopy time will increase with less than 1 minute. An
application for radiation advice is send to dr.ir. G.J.Streekstra.