This four year Merit Review proposal directly compares the efficacy of two markedly different exercise models in veteran stroke survivors, within the context of an overall cardiovascular risk factor reduction program. We will gain insight into how these programs are translated into VA community settings (Loch Raven Community-Based Outpatient Center and VA Perry Point), as well as the ideal order of initiation when participants are exposed to both interventions in a counterbalance manner over 12 months. We hypothesize that initiating the proposed 12-month cross-over intervention with higher intensity treadmill training (HI-TM) (months 0-6) followed by a lower intensity group exercise program (LILI) (months 6-12) will result in the largest long-term impact on functional and behavioral outcomes. Specifically, we propose that HI-TM will establish a baseline level of cardiovascular fitness and endurance such that that the balance and gait training in LILI can be optimally applied for the greatest benefit in months 6 through 12. Conversely, the opposing intervention pattern of LILI followed by HI-TM may produce the greatest cardiometabolic adaptations by month 12, given that that stroke survivors in this group will start HI-TM at month 6 with a higher level of baseline functional competence.
The Specific Aims are: (1) Directly compare the effects of 6-months HI-TM, LILI and EC (education control) regimens on functional, cardiometabolic, behavioral, and quality-of-life outcomes in disabled veteran stroke survivors;(2) Assess whether order of implementation impacts gains in each outcome category during a cross-over period to 1 year;(3) Compare the durability and continuation of all outcome gains in cohorts performing ongoing formal center-based training versus cohorts undergoing only home-based exercise during months 12-18. The proposal consists of eight phases that are estimated to take each treatment arm cohort approximately 20 - 21 months to complete. During phase 1 (ongoing) we will screen and consent chronic stroke patients (4 cohorts of 30 each). Phase 2 will consist of baseline testing that includes assessments of peak aerobic capacity, oral glucose tolerance, ambulatory function, balance, free-living physical activity, self-reported physical activity, lifestyle behaviors, self-efficacy/ outcome expectations for exercise, stage of readiness to change exercise behavior, functional status and perceived quality of life. Volunteers are then randomized to either HI-TM, LILI or EC for 6 months (phase 3). All groups, including EC, will receive evidence-based education and counseling for adherence to the American Stroke Association's guidelines for prevention of secondary stroke. In Phase 4, all baseline testing and analyses are repeated. In Phase 5, those in the two treatment arms commence with an additional 6-month cross- over period with all measures repeated at 12 months (Phase 6). Finally, Phase 7 relates to exploratory Aim 3 (suggested by reviewers) during which half of participants continue formal center-based exercise training for comparison at month 18 (Phase 8) with those who discontinue formal training in favor of home-based exercise recommendations.
Aim 3 will provide important preliminary information on the exercise requirements for adding to or durably maintaining outcome gains over an extended period after disabling stroke. The work proposed in this Merit Award addresses a number of factors that will help define new evidence for rehabilitation models within the VHS. Current methods of stroke rehabilitation do not effectively prevent or reverse changes in metabolic fitness, function, and declining activity patterns, causing decrements to both physiological and psychological health. The proposed study will provide foundational evidence for translating exercise models into the community, with the potential to ultimately change the current standard of care by altering the way disabled veteran stroke survivors are counseled and transitioned following completion of conventional therapy post stroke.