Study to Determine the Safety and Feasibility of Utilizing the CD Leycom Pressure/Conductance Catheter to Determine Optimal LV Pacing Site

Background

Cardiac synchronization therapy (CRT) is recognized as effective adjunctive therapy for
heart failure; however, up to 40% of patients who undergo CRT device placement do not have a
favorable response to therapy and are labeled non-responders. The lateral wall of the left
ventricle (LV) is generally regarded as the optimal site for LV lead placement and some
non-responders with LV leads not on the lateral wall can be converted to responders by
repositioning the LV lead to the lateral wall. However, recent studies indicate that in some
patients LV lead placement at a site other than the lateral wall may result in a better
response to CRT. In such circumstances, empiric lateral wall lead positioning/repositioning
may expose patients to the risks of another invasive procedure (including an increased risk
of infection); in the case of lead repositioning to improve response to CRT the additional
risk is doubled, as there is no certainty that the new position will be superior to the old.

Several investigators have used the acute hemodynamic response to biventricular pacing to
determine the optimal LV lead position. To make these measurements some groups used a
Millar pigtail catheter (Millar Instruments, Houston, Texas) while other groups used
real-time pressure volume loops with a combined pressure-conductance catheter (CD Leycom,
Zoetermeer, the Netherlands). One criticism of this method is that acute hemodynamic
measurements may not correlate to long term response. However, Delnoy et al demonstrated
that acute improvements in LV function as measured by pressure-volume loops during
implantation corresponded to clinical and echocardiographic improvement during follow-up.
In addition, Duckett et al demonstrated that the acute dP/dt response to LV pacing is useful
for predicting which patients are likely to remodel in response to CRT, for both dilated and
ischemic cardiomyopathy.

Despite these observations, few practitioners routinely utilize acute hemodynamic
measurements for LV lead placement at the time of device implantation. Many practitioners
believe targeted LV lead placement is impractical due to the time required to determine
hemodynamic response to CRT and reposition the LV lead, and that venous anatomy, phrenic
nerve pacing, and high pacing thresholds severely limit options for LV lead placement.

Study Hypothesis

It is hypothesized that it is both safe and feasible to use an interventional approach to LV
lead placement (placing the LV lead guided by acute hemodynamic measurements), and that the
LV lead can be placed in a position that is superior to the initial empiric lateral wall LV
lead location in less than 30 minutes without significant risk to patients. The time from RV
capture to LV activation correlates with the optimal pacing site based on stroke volume &
dP/dt measurements.

Study Purpose

The purpose of this study is to determine whether utilizing the CD Leycom
pressure-conductance catheter to measure dP/dt and pressure volume loops at the time of LV
lead implant (whether for the initial CRT implant or revision of an existing system) is both
safe and feasible. It is hoped that the study will determine whether it is possible to use a
patient's hemodynamic response to pacing to locate an LV pacing site that provides better
hemodynamic response to CRT than the empirically selected lateral wall pacing site without
significant patient risk (in terms of radiation exposure, amount of contrast received,
procedure time, potential injury).

Inclusion Criteria

1. Ischemic or non-ischemic cardiomyopathy

2. Patient meets all current criteria for CRT (NYHA Class III-IV heart failure, QRS ≥
120 ms, LVEF ≤ 35%, optimal medical therapy).

3. Patient willing/able to sign study informed consent and HIPAA authorization.

Exclusion Criteria

1. Patient does not meet current criteria for CRT implant

2. Mechanical aortic valve

3. Left ventricular thrombus

4. Aortic stenosis

5. No palpable femoral pulse

6. Extensive atherosclerotic disease of the aorta

7. Serum creatinine > 2.5

8. Patient not willing/able to sign study informed consent/HIPAA authorization.