Cardiopulmonary and Metabolic Responses to Early Exercise in Patients After Coronary Arterial Bypass Grafting

Study Overview
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Brief Summary
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Coronary arterial bypass graft surgery (CABG) is proven safe with improved survival and greater quality of life in patients with coronary arterial disease. Evidences on the cardiovascular and gas-exchanges responses during and right after early exercise-based rehabilitation of this patients are limited. Objective: The investigators aim to analyse breath-by-breath cardiopulmonary and metabolic responses during six-minute walk test (6MWT) and shuttle walk test (SWT) in patients with or without left ventricular dysfunction (LVD) after CABG. In addition, the investigators will investigate oxygen consumption and cardiopulmonary responses during the early exercise-based rehabilitation in the first days after surgery. Methods: According to the left ventricular ejection fraction (LVEF), subjects will be allocated into two groups: with LVD (LVEF < 45%) and without LVD (LVEF > 45%). Patients will be submitted to the 6MWT and SWT linked to portable spirometric-telemetric device before and 6 days after CABG. During the first days after surgery, patients will be evaluated about pulmonary function and respiratory strenght at rest and oxygen consumption during the portable cycle ergometer protocol. Clinical outcomes as time to hospital discharge, pulmonary complications and occurence of arrythmias will be assessed during inpatient time until hospital discharge. Incidence of mortality, hospital readmission and angina recurrence will be evaluated in a one-year follow up.

Official Title
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Cardiopulmonary and Metabolic Responses in Early Exercise-based Rehabilitation in Patients With or Without Left Ventricular Dysfunction After Coronary Arterial Bypass Grafting

Conditions
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Acute Myocardial Infarction: Rehabilitation Phase, Coronary Artery Bypass Graft Triple Vessel, Physical Activity

Intervention / Treatment
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* Other: Cycle ergometer exercise rehabilitation protocol


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age between 35 to 75 years old; Coronary arterial disease proved by coronary angiography Elective Coronary arterial bypass grafting Exclusion Criteria: Pulmonary chronic disease Disabling neurological or orthopedic disease Morbidity obesity Urgency surgery Bilateral pleural opening Arrhythmias during exercise protocol Prolonged mechanical ventilation (>12 hours) Inability to comprehend or perform the tests

Ages Eligible for Study
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Minimum Age: 35 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: LVEF < 45%<br>Patients with left ventricular dysfunction will be evaluated before and 6 days after after coronary arterial bypass graft surgery. Postoperatively, subjects will be submitted to a portable cycle ergometer exercise protocol from the first day until hospital discharge. | Other: Cycle ergometer exercise rehabilitation protocol<br>* Patients will be submitted to a progressive and moderate exercise protocol with a portable cycle ergometer.<br>|
| Experimental: LVEF > 45%<br>Patients without left ventricular dysfunction will be evaluated before and 6 days after after coronary arterial bypass graft surgery. Postoperatively, subjects will be submitted to a portable cycle ergometer exercise protocol from the first day until hospital discharge. | Other: Cycle ergometer exercise rehabilitation protocol<br>* Patients will be submitted to a progressive and moderate exercise protocol with a portable cycle ergometer.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Six-minute walk test to measure functional capacity | According to the preoperative six-minute walk test linked to portable ergoespirometry device, we will evaluate the decrease in functional capacity in the sixth day after surgery. | 6 days | 
| Short-term complications | Incidence of arrythmias, pulmonary complications (pleural effusion, pulmonary atelectasis and pneumonia) | Until hospital discharge, an average of 15 days | 
| Shuttle walk test to measure functional capacity | According to the preoperative shuttle walk test linked to portable ergoespirometry device, we will evaluate the decrease in functional capacity in the sixth day after surgery. | 6 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pulmonary Dysfunction | By spirometry, assessing the decrease in forced vital capacity and changes in exhaled volume forced in first second postoperativetly compare to preoperative period. | 6 days (on the 1th, 3th and 6th day after surgery) | 
| Respiratory weakness | By manovacuometry, assessing the change in inspiratory muscle pressure and expiratory muscle pressure postoperativetly compare to preoperative period. | 6 days (on the 1th, 3th and 6th day after surgery) | 
| Oxygen Consumption | Evaluate the oxygen consumption in metabolic equivalents (METS) during the cycle ergometer in post operative period by using spirometic-telemetric portable device during sessions. | First 6 days after surgery | 
| Mid and Long Term Complications | Complications such as angina recurrence, hospital readmission, cardiac events and all cause mortality. | 3 months to 1 year |