Cardiac Resynchronization Therapy in patients with systolic Heart Failure and mechanical dyssynchrony undergoing Coronary Artery Bypass Grafting

Cardiac Resynchronization Therapy (CRT) is a standard therapy for patients with
chronic systolic heart failure (LVEF <35% and heart failure symptoms NYHA
III-IV) already on optimal medical treatment, with a wide QRS complex on their
ECG (> 120 ms) as a measure of electrical dyssynchrony. CRT normalizes in this
patient population (through biventricular pacing) the contraction pattern of
the heart, which results in an improved cardiac function and clinical outcome
as demonstrated in several landmark trials (CareHF, Companion, Miracle, MADIT
CRT): reverse remodeling of the heart, improved EF, improvements in exercise
capacity and physical activity, improvements in quality of life, reduced
symptoms of heart failure, reduction the number of hospital admissions for
heart failure and an improved survival. Ischemic patients undergoing Coronary
Artery Bypass Grafting (CABG) surgery have been excluded from these large
randomized CRT trials. Currently, no data exist on the impact of CRT in
patients requiring revascularization. Penicka and co-workers (Penicka et al,
JACC 2007) have recently shown that HF patients with severe left ventricular
(LV) mechanical dyssynchrony have a poor outcome after CABG. It is hypothesized
that patients with severe LV dyssynchrony would benefit from CRT in addition to
surgical revascularization in terms of reverse LV remodeling and improved
clinical outcome.

Inter-individual comparison of the effect of CRT (immediate application of CRT
after CABG surgery) on the improvement in left ventricular remodeling, left
ventricular function and clinical outcome in patients with systolic heart
failure and severe LV mechanical dyssynchrony who are undergoing CABG surgery.

prospective
randomized (1:1)
parallel
open label
multicenter
international

Patients are randomized into two groups: immediate treatment with CRT or
standard medical therapy after CABG surgery. The patients in the "CABG +
immediate CRT" group receive during or shortly after CABG surgery a CRT
pacemaker (Biventricular Pacemaker). The control group receives standard
medical follow-up after CABG surgery and will follow the routine clinical
practice.

In the treatment group, a CRT pacemaker is implanted during or shortly after
the CABG surgery. Potential risks and discomforts associated with this study
are those typically related to the implantation of a CRT pacemaker and are
explained in the patient information form. The implantation of a biventricular
pacemaker is a routine clinical practice in the participating hospital and is
only done by cardiologists/surgeons with the necessary experience in the field.
The implantation of a CRT pacemaker during the CABG operation will prolong the
the surgery time with possible additional risks as a result (increased risk of
infection). If the clinical condition of the patient does not allow a CRT
pacemaker to be implanted immediately during the CABG surgery, than the CRT
pacemaker will be implanted in a seperate procedure (during the same
hospitalization). This is a short procedure corresponding to the implantation
of a standard pacemaker.
There are no known risks associated with an ultrasound echocardiography, but
there is a potential for a rare anaphylactoid reaction to the contrast agent.
This will be discussed with the patient and the treating doctor will provide
the necessary precautions. This echocardiogram with the use of contrast agent
will be repeated 3 times: baseline, 6 and 12 months after the CABG surgery.
Collection of study-specific data (QOL questionnaire, six minutes walk test,
echocardiography, blood sample) is done during the routinely scheduled control
visits in line with the normal clinical practice: 1 month, 6 months and 12
months after CABG surgery. Blood sampling during the follow-up visits is a
routine practice.