Clinical Investigation on differences in the magnitude of CRT response in WOmen versus MEN

Revision of the major published CRT and HF trials indicate that women are
under-represented in HF trials compared to man, with the average women
enrollment rate in between 25% and 30% of the total HF population. Sub-analyses
of these big CRT trials (with only 25-30% of females) indicates that females
could have a better response to CRT. Single center retrospective research has
recently shown in a highly selective patient population (only non-ischemic
patients with an LBBB) that females have a better response to CRT compared to
men. We would like to study this prospectively in an unbiased "real life" HF
patient population with an equal distribution of males/females. This could lead
to gender specific selection criteria for CRT.

The general objective is to study gender differences in the magnitude of CRT
response in a HF population with an equal distribution of women and man in
order to examine the interrelationship among CRT effect, gender and baseline
clinical factors (e.g. like QRSd).
The primary objective is to study the magnitude of CRT response in women
measured as a function of improvement in LVEF in order to demonstrate overall
superiority of CRT response in women.

In the secondary objectives we will investigate gender differences based on:
- changes in major clinical variables during a 12M FU period in men and women.
- changes in Left Ventricular End Diastolic Volume (LVEDV) and Left Ventricular
End Systolic Volume (LVESV)
- differences at baseline with regards of presence of inter/intra ventricular
dyssynchrony, HF etiology (ischemic versus non-ischemic cardiomyopathy), QRS
morphology (LBBB vs. RBBB) and QRSd in a group of CRT responders (female vs
male)
- observational assessment of how key clinical variables are related to the
patient's CRT response, to create a possible *gender specific* response model.
- the relationship between QRS duration and CRT response in men and women.

Observationel study to asses the HF status and CRT response over a period of 12
months with non-invasive daignostics (echocradiography, ECG, NYHA, QOL test, 6
minute hall walk test, SAE reporting...). Prospective research on an equal
patient population of males/females from a real life patient poplation
indicated for CRT.

The burden and risks associated with participation are limited as this is an
observationel study with additional non-invasive diagnostics to asses the HF
status over a period of 12 months in order to measure the CRT response:
- a standard echocardiography of the heart to asses the heart function and
volumes: baseline, 6 and 12 month
- an ECG at baseline: QRS duration and morphology
- a 6 min hall walk test: baseline, 6 and 12 month
- a QOL questionair: baseline, 6 and 12 month
- patient self assesment (patient needs to indicate how he feels compared to
before the CRT device implant)
these tests are performed during the normal in office FUPs scheduled to check
the CRT device: a first check-up 2 months after CRT implantation and every 6
months. After 12 months the study is finished.