This study will be evaluate the autonomic, endothelial and hemodynamic functions, inspiratory muscle strength, peripheral tissue oxygenation, peripheral and respiratory muscle architecture, and inflammatory profile of severe AS patients submitted undergoing to valve replacement (sAVR) or transcatheter aortic valve implantation (TAVI), and their influence on the pathophysiological mechanisms involved in cardiovascular rehabilitation.

Background: Aortic stenosis (AS) is a disease characterized by the inadequate valve opening, compromising the cardiac output. Surgical aortic valve replacement (sAVR) is the procedure indicates for valve repair in AS symptomatic cases whereas the transcatheter aortic valve implantation (TAVI) is the procedure indicates for sAVR contraindicated cases.

Objective: To evaluate the effect of the cardiac rehabilitation program (pre-procedure, early post-procedure, and late post-procedure) in autonomic, endothelial and hemodynamic functions, inspiratory muscle strength, peripheral tissue oxygenation, peripheral and respiratory muscle architecture, and inflammatory profile of severe AS patients submitted to a valve repair procedure (sAVR or TAVI).

Methods: The present study will be a randomized double-blind clinical trial in patients indicated to valve repair procedure. This research will be divided into four phases: phase 1 (pre-procedure); phase 2 (early post-procedure); phase 3 (late post-procedure) and phase 4 (follow-up). Phase 1: participants will be randomized in PR-I (pre-intervention) or PR-C (control). Pre-procedure rehabilitation program will consist of daily neuromuscular electrical stimulation (NMES) in knee extensor muscles and inspiratory muscle training (IMT) sessions. PR-C group will receive daily visits, but with a NMES + IMT protocols using a minimal load. Phase 2: a new random will be done between ER-II or ER-CI (intervention) and ER-IC or ER-CC (control). Intervention groups will undertake an early post-procedure rehabilitation (NMES in knee extensor muscle plus IMT for six weeks). Control groups will receive the same protocol using a minimal load without load progression. Phase 3: all patients will be referred to the conventional cardiac rehabilitation program (aerobic and resistance training) for 8-weeks. Phase 4: follow-up (no interventions), will be done after 3, 6, 9 and 12 months. Assessment protocol will be composed by cardiopulmonary exercise test, autonomic (heart rate variability), endothelial (flow-mediated vasodilation), hemodynamic function (cardiothoracic impedance) functional capacity (six-minute walk test), maximum inspiratory pressure, peripheral and respiratory muscle architecture (ultrasonography), and tissue oxygenation (near-infrared spectroscopy), and inflammatory profile (OxLDL, TGF-β, TNF-α, IL-1b, IL-10 and ICAM-1) Appropriate statistic tests will be used to compare the time-rehabilitation (experimental vs sham) and group-interaction (sAVR vs TAVI). If samples are abandoned or lost, basal data will be double entered to characterize the intention-to-treat analysis.

Inclusion Criteria: patients NYHA class II-IV who has not participated in a CRP three months before recruitment; older than 40 years; of both genders; with degenerative AS and indication for valve repair. The patients will not know which protocol to undergo.

Exclusion Criteria: patients with low cognitive level to perform the assessment or intervention procedures; that exhibit unstable angina or any contraindications for the treatment or measurements; as well musculoskeletal, cerebrovascular, or psychiatric disease that prevents their participation in the research.