E-pot Study: EnSite & Pressure- Volume in Cardiac Resynchronization Therapy, a multicenter, prospective, feasability, non-randomized pilot study

Today it is relatively well accepted that cardiac resynchronization therapy
improves hemodynamic parameters, exercise capacity, symptoms, and quality of
life and also reduces hospitalization among patients with severe heart failure,
impaired LV function and widened QRS complex usually with a left bundle branch
block. Devices that combine biventricular pacing with an implantable
defibrillator have moreover demonstrated a significant reduction in arrhythmic
death in high-risk population.
The responsible mechanisms are believed to include improved synchrony of the
timing of left and right ventricular (RV) systole (interventricular synchrony),
improved synchrony of the different segments of the left ventricle
(intraventricular synchrony), and a reduction in mitral regurgitation.
However, it was noted that 25% to 30% of patients did not respond to CRT,
emphasizing the need for better selection criteria. In this frame, the
resynchronization of pre-existent LV dyssynchrony is considered a major player
in determining the response to CRT [Yu, Bax]. Indeed detailed echocardiographic
assessment using tissue Doppler echocardiography showed that patients with left
bundle-branch block (LBBB) have marked intraventricular dyssynchrony that can
be improved by biventricular pacing. [Yu Circ 2002].
Another potential reason for non-response to CRT (in patients with ischemic
cardiomyopathy) may be the presence of extensive scar tissue in the region of
the tip of the LV pacing lead [Bleeker et all Circ 2007]

The main objective of this study is:
• To determine the optimal site to position the left ventricular pacing
lead for each individual patient with an ischemic Cardiomyopathy (CMP). The
site is selected based on the latest mechanical activated site and the latest
electrical activated site, whatever pacing configuration tested.
• To assess changes in activation pattern and the hemodynamic effects
due to (single- or dual-site) left ventricular and biventricular pacing.

The following objectives will also be assessed:
• The relationship between the electrical and mechanical delay.
• The relationship between scar characteristics and the latest
electrical and mechanical areas activated

This clinical trial is a multicenter, prospective, feasibility, non-randomized
pilot study.
All patients taking part in this study will undergo the implantation of a CRT-D
device with transvenous leads. After successful implantation and after hospital
discharge, patient will be followed for 6 months after implant. The invasive
part of the study contents two phases where in phase I endocardial mapping and
PV-loop measurements are performed. In phase II the device will be implanted at
the pre-defined optimal lead position(s) and pacing configuration.


Patients will attend protocol scheduled visits before implant (pre-implant
evaluation), and post-implant: pre-hospital discharge and at 6 months.

There is a mild extra risk in concordance to the regular diangnostics in
patient with inschemic heartfailure, as MRI, echocardiography and
electrophysiologic evaluation. During the first invasive fase Pressure-volume
loops are measurend using a conductance catheter in the left ventricle. The
risk of left ventricular catherization is similar to regular evaluation of
coronary arteriography in patients with coronary artery disease.