Risk Stratification and Benefits With Cardiac Resynchronization Therapy (CRT)

The purpose of the study is two-fold. First, to determine if an algorithm can be developed
based on pre-implant clinical variables to predict response to CRT-D therapy. Second, the
study aims to determine in patients implanted with CRT-D if the combined use of cTnT and BNP
can further predict and risk-stratify HF improvement and all-cause mortality. Additionally,
novel biochemical markers defining cardiac mortality in high risk patients detected by plasma
proteomic analysis in the CRT-D patients will be evaluated.

This study represents a combination of previous CRT studies that evaluated these variables
independently. Data from this study will be pooled with data from previous studies to build a
more complete picture of CRT therapy.

Inclusion Criteria:

- Meets current clinical indications for CRT-D therapy

- Patient is 18 years old or older

- Ability to independently comprehend and complete all QOL questionnaires

- Patient has the ability to perform the 6-minute Hall Walk Test (6-MHW) with the only
limiting factor being fatigue or shortness-of-breath

- Ability to provide informed consent for a study and be willing and able to comply with
the prescribed follow-up

Exclusion Criteria:

- Inability to successfully implant an intravascular lead and CRT-D device. (i.e.
exclude epicardial leads) within 30 days of initial procedure.

- Myocardial infarction in the last 3 weeks

- Unstable angina in the last 3 weeks

- Status 1 classification for cardiac transplantation

- Currently participating in a clinical trial that includes an active treatment arm

- Life expectancy of less than 12 months.

- Recent (within 1 week) administration of Nesiritide™ or inotropes

- Patients in whom revascularization is expected

- Patient is pregnant