Effects of Exercise Training on Fluid Instability in Heart Failure Patients

Charlie Norwood Va Medical Center, Augusta GA

Investigators

Abstract

Abstract TITLE: Effects of Exercise on Fluid Balance Instability in Heart Failure Patients BACKGROUND / RATIONALE: Heart Failure (HF) is a significant healthcare concern in the US with a 120% rise in mortality rates over 15 years costing the country an estimated $37.2 billion in 2009. Veterans are currently impacted at a rate of 5.2% and a cost an average of $14,959/individual/year for those utilizing the Veteran Administrations Healthcare services. Research has shown that exercise training (ET) improves aerobic capacity, endothelial dysfunction, quality of life, and the ability to tolerate activity within the overall HF population. Animal models have emerged to explain some of the underlying mechanisms for the pathologic expression of symptoms and the links to ET, including plausible links between endothelial dysfunction, fluid instability, and the role of ET. A translational link has not yet been explored between the animal models and human symptom expression. OBJECTIVE(S): The long term goal of this research program is to develop an exercise training (ET) program that effectively decreases fluid shift variability in heart failure (HF) patients, while being safely implemented in the home environment and remotely monitored by a healthcare provider within a nurse lead HF Clinic. The purpose of the proposed research project is to determine if ET alters fluid status of patients with HF as compared to those under standard treatment of care. The central hypothesis is that a combined weight-bearing aerobic and resistance ET protocol will reduce (stabilize) 24-hour weight and bioelectrical impedance patterns of variability as evaluated via mixed-effects regression modeling greater than any other form of ET protocol. METHODS: Design: Using established experimental design techniques implemented in an innovative manner, a between group design will be used within the experimental arm employing a single subject, multiple-baseline design. The use of such technique will allow for the subjects to be their own controls while also allowing for statistical group comparisons. Subjects and Setting: 60 subjects meeting inclusion/exclusion criteria will be recruited/enrolled from the VA HF Clinic and outpatient VA cardiology clinics within 50 miles of Augusta. Subjects will then be randomized to the exercise or usual care groups. Interventions and Procedures: The exercise protocol will last 12 weeks. Subjects will be randomized to order of ET. Weight-bearing aerobic ET will be walking on a treadmill, non- weight-bearing aerobic ET will be stationary bicycling, and resistance ET will be lower body isolation ET. Fluid stability is the concept of day to day variability of movement of intra-cellular fluid to extra-cellular space. Fluid stability will be assessed using 24-hour weight and bioelectrical impedance and quantified statistically. Data Analysis: Statistical analysis will utilize a longitudinal mixed-effects regression model, modeling variability over time for the subjects individually, as well as, within groups.