Effects of High-intensity Inspiratory Muscle Training in Patients Undergoing Coronary Artery Bypass Grafting Surgery

Effects of High-intensity Inspiratory Muscle Training Associated With Aerobic and Resistance Exercise in Patients Undergoing Coronary Artery Bypass Grafting Surgery

Even with the advances in clinical therapy and percutaneous interventions, coronary artery bypass grafting (CABG) is still widely used in the treatment of patients with coronary artery disease (CAD). However, it is a complex procedure that triggers important organic implications especially on pulmonary function. In relation to the treatment of patients undergoing CABG, the recovery is linked to the cardiac rehabilitation programs. These programs can also be associated with other muscle training measures, among these there is inspiratory muscle training (IMT). Most studies has been implemented moderate-intensity IMT daily, but there are few studies about the effects of high intensity training loads performed on alternate days. In this context, is justified the use of a device such as the recent Powerbreathe, which uses higher training loads that would provide greatest benefits, whereas the magnitude of the response to training tends to increase with load.

OBJECTIVE: To investigate the efficiency of high intensity IMT associated with combined aerobic and resistance training on maximal exercise capacity, submaximal exercise capacity, respiratory muscle strenght, pulmonary function, oxidative stress, quality of life and endothelial function in patients who underwent CABG in phase II cardiac rehabilitation program.

METHODOLOGY: This is a clinical trials, controlled, randomized,double-blind being developed in partnership with Cardiology Clinic of Hospital Universitário de Santa Maria (HUSM), Santa Maria, RS, Brazil. Patients will undergo the evaluation of pulmonary function and respiratory muscle strength (spirometry and digital manovacuometry), as well on the maximal exercise capacity (Ergospirometry), submaximal functional capacity (6MWT and 6MST), of quality of live (MLHFQ) of Oxidative stress and endothelial function (blood biomarkers). After the evaluation will be randomly allocated into two groups: the control group will perform cardiac rehabilitation associated with the Sham of IMT, and the experimental group cardiac rehabilitation associated with the IMT High-intensity. The intervention will last twelve weeks for both groups and after this phase patients will be submitted again to the assessment tools.

EXPECTED RESULTS: The high intensity IMT potentiates the effects of cardiac rehabilitation (phase II) after coronary artery bypass surgery patients.

Inclusion Criteria:

• Patients undergoing CABG up to three weeks before the initiation of the study, a clinical course without complications during hospitalization
• Clinically stable
• The absence of smoking (previous or current).

Exclusion Criteria:

• Unstable angina
• Myocardial infarction and heart surgery up to three months before the survey;
• Chronic respiratory diseases
• Hemodynamic instability
• Orthopedic and neurological diseases that may preclude the achievement of the cardiopulmonary test and Cardiac Rehabilitation exercises
• Psychological and / or cognitive impairments that restrict them to respond to questionnaires.