Effect of Exercise Training on Left Ventricular Function in Patients Post Myocardial Infarction

Not Applicable

Completed

• Conditions: Myocardial Infarction; Heart Failure; Coronary Artery Disease
• Interventions: Other: Secondary prevention and cardiac rehabilitation clinic

• Registration Number: NCT02048696
• Lead Sponsor: Montreal Heart Institute

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.

Study Timeline

• Study First Submitted: 2014-01-22
• Study First Submitted QC: 2014-01-27
• Study First Posted: 2014-01-29
• Study Start: 2014-02
• Primary Completion: 2016-02-01
• Status Verified: 2018-10
• Study Completion: 2018-10-16
• Last Update Submitted: 2018-10-17
• Last Update Posted: 2018-10-18

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 26

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

• Pregnant
• 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
• Significant ventricular arrhythmias (non-sustained ventricular tachycardia or syncope).
• New York Heart Association class IIIb - IV symptoms.
• Severe LV systolic dysfunction (Ejection fraction ≤ 30%)
• Active decompensated heart failure with orthopnea or paroxysmal nocturnal dyspnea.
• Uncontrolled resting arterial hypertension > 180/110 mmHg.
• More than moderate systemic disease
• Chronic inflammation or infection.
• Any contraindication to exercise training or any condition limiting ability to partake in adequate exercise stress testing or training (peripheral artery disease, articular, neurologic, or psychiatric pathology)

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Exercise training	Secondary prevention and cardiac rehabilitation clinic	Secondary prevention and cardiac rehabilitation clinic of the Montreal Heart Institute. Subjects will undergo twice weekly exercise training with high intensity interval training for a period of 12 weeks.

Primary Outcome Measures

Name	Time	Method
Lymphocyte GRK2 mRNA level	at baseline and following 12 weeks exercise training intervention	change in lymphocyte GRK2 mRNA levels

Secondary Outcome Measures

Name	Time	Method
lymphocyte GRK2 protein levels	at baseline and following 12 weeks exercise training intervention	change in lymphocyte GRK2 protein levels
Left ventricular systolic function	at baseline and following 12 weeks exercise training intervention	change in left ventricular systolic function
exercise capacity (VO2max)	at baseline and following 12 weeks exercise training intervention	Change before and after exercise training
ambulatory blood pressure	at baseline and following 12 weeks exercise training intervention	Change in awake and 24h blood pressure
Plasma brain natriuretic peptide	at baseline and following 12 weeks exercise training intervention	change in plasma brain naturietic peptide
Plasma epinephrine	at baseline and following 12 weeks exercise training intervention	change in plasma epinephrine
heart rate variability	at baseline and following 12 weeks exercise training intervention	change change in autonomic tone
Left ventricular dimensions	at baseline and following 12 weeks exercise training intervention	Change in left ventricular dimensions
Maximal cardiac output and stroke volume using electrical bioimpedance	at baseline and following 12 weeks exercise training intervention	change in maximal cardiac output and stroke volume

Trial Locations

Locations (1)

Centre for preventive medicine and physical activity of the Montreal Heart Institute (Centre ÉPIC); 🇨🇦 Montreal, Quebec, Canada