Interventions to Improve Daily Activity in Heart Failure

Few studies have been able to demonstrate intervention efficacy for improving daily activity
in heart failure (HF). Exercise alone is ineffective, though psychosocial-based
interventions including health coaching and daily activity feedback appear to be promising.
Therefore, the primary purpose of the present proposed study is to investigate the effect of
two different intervention approaches (1. daily activity feedback with associated
encouragement, and 2. health coaching with an associated individualized home exercise
program) on daily activity, exercise tolerance, HF-related health status, and lower
extremity functional strength. A secondary purpose is to compare daily activity as recorded
by Medtronic® implanted cardioverter defibrillator (ICDs) and cardiac resynchronization
therapy (CRT) devices to daily activity recorded by a well-established triaxial
accelerometer.

This will be a single-blinded randomized trial, with subject randomization stratified by age
and baseline activity level. Subjects will be randomized to one of three groups: 1) A
control group receiving usual care, 2) a group receiving only feedback with associated
encouragement about their daily activity, and 3) an intervention group that will receive
health coaching with an associated individualized home exercise program.

The study will consist of a 3 month intervention period and a 6 month follow-up/ retention
period (total study enrollment period of 9 months). The primary study endpoint is Medtronic
device-measured daily activity. All study endpoints will be assessed at baseline, 3 months,
and 9 months. The investigators who are conducting study measurements will be blinded to
group assignment.

Using a previously established minimum clinically important difference (MCID) of 1.08 hours
per day for improvement in daily activity (effect size=1.54) as measured by Medtronic
ICDs/CRTs, a total of 8 subjects per group would be needed to achieve a statistical power
(1-β) of 0.80 (two-tailed, α=0.05) for a between-groups comparison utilizing two groups.
Therefore, depending on the observed effect size in the proposed study, utilizing 3 groups
with approximately 10 subjects in each group should provide adequate statistical power for a
between-groups comparison with 3 groups.

Statistical analyses will be conducted to meet the planned study objectives. With regard to
intervention effects, one way analysis of variance with planned contrasts will be used to
examine between-group differences for each of the continuous variables [Patient Activity,
Kansas City Cardiomyopathy Questionnaire (KCCQ), Patient Health Questionnaire (PHQ-9),
six-minute walk test (6MWT), 30 second timed chair rise (30-s TCR), heart rate variability,
Optivol Fluid Index]. If the data do not meet the requisite assumptions, the Kruskal-Wallis
analysis of variance by ranks will be used. Baseline to 3 months data will be used to assess
immediate intervention effects and to 9 month follow-up will be used to assess retention
effects.

With regard to concurrent validity of the Medtronic Patient Activity measurement, the
Pearson correlation coefficient will be calculated between the daily Patient Activity
(minutes per day) and two Actigraph parameters: daily activity count and steps per day.
Correlation coefficients will be calculated for the baseline, 3-month, and 9-month
monitoring periods to provide a greater number of sampling days. Correlation coefficients
will also be calculated for changes in daily activity measurements between baseline and 3
months and baseline and 9 months to determine concurrent validity of change in daily
activity measurements.

Inclusion Criteria:

- Diagnosis of heart failure with subsequent placement of a Medtronic® ICD or Cardiac
Resynchronization Therapy (CRT) device at least 6 months prior to study enrollment

- New York Heart Association Functional Class II to III symptoms on optimal medical
therapy

Exclusion Criteria:

- Any comorbid medical disease that would prevent safe participation in an
individualized exercise program such as severe osteo-, rheumatoid-, and gout-related
arthritis, unstable angina, exercise-induced arrhythmias, uncontrollable diabetes, or
atrial fibrillation with rapid ventricular rate in the preceding 30 days.

- Recent (<6 weeks) or planned (<6 months) major cardiovascular events or procedures

- Current participation in a regular exercise training program

- HF due to severe, uncorrected primary valvular disease, congenital heart disease, or
obstructive cardiomyopathy

- Adults unable to consent (e.g. cognitively impaired), pregnant women, and prisoners