Effect of Exercise Training on Left Ventricular Function in Patients Post Myocardial Infarction: The EXercise Interval Training - V Study
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Myocardial Infarction
- Sponsor
- Montreal Heart Institute
- Enrollment
- 26
- Locations
- 1
- Primary Endpoint
- Lymphocyte GRK2 mRNA level
- Status
- Completed
- Last Updated
- 7 years ago
Overview
Brief Summary
Patients who have suffered a heart attack are at risk of developing worsening heart function and heart failure. Exercise training has a beneficial effect on heart function and prevents heart failure. The aim of the current study is to investigate the effect of exercise training on heart function in patients who have suffered a heart attack.
Detailed Description
Patients who have suffered a myocardial infarction are at significant risk for developing heart failure and progressive left ventricular dysfunction One of the proposed mechanisms responsible for this observation is reduction in myocardial beta-adrenergic receptor density due to elevated cell membrane protein G - protein coupled receptor kinase -2 (GRK2). It is known that exercise training preserves heart function in patients who have suffered a myocardial infarction. The mechanism for this is not clear. The purpose of this study is to examine the effect of exercise training on myocardial function and GRK2 levels in patients who have suffered a myocardial infarction, with the hypothesis that exercise training in this population reduces GRK2 levels and preserves or improves myocardial function.
Investigators
Eligibility Criteria
Inclusion Criteria
- •Acute myocardial infarction
- •Complete revascularization: no residual major epicardial coronary artery coronary stenosis ≥ 70%; no residual left main coronary stenosis ≥ 40%.
- •Stage A-C heart failure, New York Heart Association class I-III.
- •Stable dose of medications during the 4 weeks prior to enrolment.
- •Able to perform a maximal cardiopulmonary stress test.
- •Capacity and willingness to provide sign informed consent.
Exclusion Criteria
- •Coronary artery bypass surgery: patients post coronary artery bypass graft exhibit wall motion abnormalities that may interfere with speckle tracking analysis.
- •Incomplete revascularization with major epicardial coronary artery (left anterior descending, circumflex, or right coronary) stenosis ≥ 70%.
- •Myocardial necrosis in the absence of significant flow limiting coronary artery stenosis or thrombosis, with the exception of documented STEMI and successful thrombolytic therapy resulting on no significant residual epicardial coronary artery stenosis.
- •Significant valvular disease that is greater than moderate in severity
- •History of non-ischemic cardiomyopathy (dilated, restrictive, infiltrative cardiomyopathy, hypertrophic, LV non compaction, or Takotsubo cardiomyopathy)
- •Significant resting ECG abnormalities that preclude accurate speckle tracking.
- •Paced rhythm.
- •left bundle branch block
- •Atrial arrhythmias (ex. persistent/permanent atrial fibrillation, atrial flutter).
- •Frequent ventricular ectopics
Outcomes
Primary Outcomes
Lymphocyte GRK2 mRNA level
Time Frame: at baseline and following 12 weeks exercise training intervention
change in lymphocyte GRK2 mRNA levels
Secondary Outcomes
- lymphocyte GRK2 protein levels(at baseline and following 12 weeks exercise training intervention)
- Left ventricular systolic function(at baseline and following 12 weeks exercise training intervention)
- exercise capacity (VO2max)(at baseline and following 12 weeks exercise training intervention)
- ambulatory blood pressure(at baseline and following 12 weeks exercise training intervention)
- Plasma brain natriuretic peptide(at baseline and following 12 weeks exercise training intervention)
- Plasma epinephrine(at baseline and following 12 weeks exercise training intervention)
- heart rate variability(at baseline and following 12 weeks exercise training intervention)
- Left ventricular dimensions(at baseline and following 12 weeks exercise training intervention)
- Maximal cardiac output and stroke volume using electrical bioimpedance(at baseline and following 12 weeks exercise training intervention)