Table 1 Inclusion and exclusion criteria

A previous diagnosis of chronic heart failure

Major cardiovascular event within 6 weeks prior to enrolment

Cardiac Resynchronisation Therapy Device (CRT) implanted at least six months prior to enrolment.

Uncontrolled hypertension

A history of symptomatic congestive heart failure (NYHA Class II to IV).

Participation in any other clinical trial which would conflict with this trial

At any time in the past, an ejection fraction <40% or documented moderate to severely impaired systolic dysfunction.

Any condition that will preclude them from walking on a treadmill adequately or participating fully in the study

Stable medical therapy for heart failure

The patient is willing, able, and committed to participate in the study for the full length of the follow-up.

>90% biventricular pacing at entry