50 Stratos LV/LV-T Technical Manual

Primarily, the study evaluates and compares the functional benefits of CRT between the two randomized groups using a composite endpoint consisting of a six-minute walk test (meters walked) and quality of life measurement (assessed using the Minnesota Living with Heart Failure Questionnaire). Relevant measurements were completed twice for each patient: once at the Baseline evaluation (two-week post implant follow-up) and again at a six-month follow-up evaluation. The data collected during this clinical study was used to demonstrate equivalent treatment of CHF in both the study and control groups. This study also evaluated other outcomes including: the percentage of time CRT is delivered, and other measures of CHF status, including NYHA classification, peak oxygen consumption during metabolic exercise testing, and the rate of hospitalization for CHF.

Clinical Inclusion Criteria

To support the objectives of this investigation, patients were required to meet the following inclusion criteria prior to enrollment:

•Stable, symptomatic CHF status

•NYHA Class III or IV congestive heart failure

•Left ventricular ejection fraction ≤ 35% (measured within six-months prior to enrollment)

•Intraventricular conduction delay (QRS duration greater than or equal to 130 ms)

•For patients with an existing ICD, optimal and stable CHF drug regimen including ACE-inhibitors and beta- blockers unless contraindicated (stable is defined as changes in dosages less than 50% during the last 30 days)

•Indicated for ICD therapy

•History or significant risk of atrial tachyarrhythmias

•Willing to receive possibly uncomfortable atrial shock therapy for the treatment of atrial tachyarrhythmias

•Able to understand the nature of the study and give informed consent