Premature Fatigue in Veterans With Heart Failure: Neuronal Influences

Completed · Early Phase 1

Conditions studied: Heart Failure

In brief

A hallmark of patients with heart failure (HF) is premature fatigue which impairs their quality of life and depicts a major source of morbidity. Premature fatigue may be attributed to a) contraction-induced transient changes within muscles (i.e. peripheral fatigue) and/or b) failure of the central nervous system to 'drive' / activate locomotor muscles (i.e. central fatigue). Both determinants of fatigue can lead to a reduction in a muscle's force and power generating capacity and to a compromised ability to perform whole body activities (e.g. walking). Recent findings in health have documented that group III/IV afferent fibers from the working muscle play a critical role in the development of both components of fatigue. Specifically, group III/IV muscle afferents limit central motor drive (CMD) during exercise and thereby exaggerate the development of central fatigue. In contrast, muscle afferents optimize muscle O2 delivery through the precise regulation of circulation and ventilation during exercise and thereby attenuate the development of peripheral fatigue.

Key facts

Study ID

NCT02209610

Run by

VA Office of Research and Development

People needed

32

Starts

2015-07-01

Expected to finish

2017-01-15

Last updated by the study team

2019-08-02

Who can join

Age: 20 and older, up to 75. Sex: any. Healthy volunteers: accepted.

You may qualify if…

• subjects with a history of stable cardiomyopathy (ischemic and non-ischemic, >1yr duration, ages 20-75 yr),
• not pacemaker dependent (no biventricular pacers),
• NYHA class II and III symptoms,
• Left ventricular ejection fraction (LVEF)<35%,
• no or minimal smoking history (<15 pk yrs) and on stable medications.
• The investigators will also study subjects with preserved ejection fraction
• heart failure with a preserved ejection fraction (HFpEF);
• LVEF >50%,
• >1yr duration,
• ages 20-75 yr,
• not pacemaker dependent,
• NYHA class II and III symptoms,
• no or minimal smoking history (<15 pk yrs) and on stable medications. The investigators will exclude morbidly obese patients (BMI >35), patients with uncontrolled hypertension (>160/100), anemia (Hgb<9) and severe renal insufficiency (individuals with creatinine clearance <30 by the Cockcroft-Gault formula).

You may not qualify if…

• Patients with significant non-cardiac comorbidities, which if present could alter the study results, will be excluded.
• Patients will be sedentary, defined here as no regular physical activity for at least the prior 6 months and current activity level will be documented by an activity questionnaire.
• Candidates must have no orthopedic limitations that would prohibit them from performing exercise.
• Due to the typical age of patients with heart failure, all women will be postmenopausal (either natural or surgical) defined as a cessation of menses for at least 2 years,
• and in women without a uterus, follicle stimulating hormone (FSH) >40 IU/L.
• Women currently taking hormone replacement therapy (HRT) will be excluded from the proposed studies due to the direct vascular effects of HRT.
• Patients with a pacemaker and / or defibrillator will be excluded from the study due to the use of a magnetic/electric stimulators.

Where it is running

• VA Salt Lake City Health Care System, Salt Lake City, UT — Salt Lake City, Utah, United States

Full record on ClinicalTrials.gov

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