This study will evaluate the effect of a cardiac rehabilitation (CR) programme on blood protein molecules that may improve the function of arteries in coronary artery disease (CAD) patients who have suffered a heart attack. CAD patients who have either agreed or disagreed to take part in a CR programme will be recruited. This will allow a comparison of the study measurements between a group of patients who complete a CR programme and a group of patients who do not.

The other objective of this study is to perform interviews with the study participants and their significant others (i.e. spouse, family member, or a close friend) to listen to the reasons why patients agreed or disagreed to take part in a CR programme.

An exercise-based cardiac rehabilitation (CR) programme is an established method of secondary prevention of coronary artery disease (CAD). Moreover, there is a body of evidence that supports the ability of this intervention to reduce hospital readmissions and cardiovascular mortality. However, despite the proven benefit, CR programmes are underutilised worldwide. Moreover, the molecular mechanisms responsible for orchestrating the beneficial physiological adaptations induced by a CR programme are poorly understood.

Therefore, this study will evaluate the effect of a CR programme on novel molecular mechanisms and endothelial function in post-myocardial infarction CAD patients. Additionally, semi-structured interviews will be conducted with study participants and their significant others (i.e. spouse, family member, or a close friend) to explore the reasons why patients may agree or disagree to take part in a CR programme. Altogether, this study will provide physiological and detailed qualitative information that may help to provoke an increased participation in CR programmes.

Inclusion Criteria:

• Formally diagnosed coronary artery disease with evidence of ST- elevated or non-ST elevated myocardial infarction, as determined by evidence of myocardial necrosis in a clinical setting consistent with acute myocardial ischemia, and the detection of a rise and / or fall in cardiac biomarker values (preferably cardiac troponin), with at least one value above the 99th percentile upper reference limit, along with at least one of the following:

Symptoms of ischaemia, such as: extreme fatigue, breathlessness, chest pain, and heart palpitations.

New or presumed new significant ST-segment-T wave changes or new left bundle branch block.

Development of pathological Q waves on the electrocardiogram.

Imaging evidence of new loss of viable myocardium or new regional wall motion abnormality.

Identification of an intracoronary thrombus by angiography

• Over 18 years of age.
• Male or Female.
• Provision of informed consent.
• Ability to speak and write in English.
• Patients who have agreed to participate in a phase-III cardiac rehabilitation programme must be willing to attend the supervised group exercise sessions.
• No hospital readmissions with unstable symptoms (e.g. chest pain, shortness of breath, discomfort, or nausea) during the previous 4-weeks.
• Willing to comply with trial requirements.

Exclusion Criteria:

• Unstable angina pectoris (angina at rest or persistent angina regardless of pharmacological treatment e.g. glyceryl trinitrate).
• Uncontrolled cardiac arrhythmia.
• Survivor of cardiac arrest or cardiogenic shock.
• Any form of anaemia (haemoglobin < 90 grams / litre).
• Hepatic failure.
• Uncontrolled hypertension (resting systolic measurement > 180 mm Hg and / or diastolic measurement > 100 mm Hg).
• History of Raynaud's phenomenon.
• Congenital or acquired physical abnormalities of both arms.
• Consumption of vitamins, herbal, testosterone, estrogen/ progesterone, or antioxidant supplementation.
• Pregnant.
• History of or diagnosed with any form of cancer.
• Current participation in a different research study.

Patient Inclusion Criteria for Interview Component of Study:

• Patient has either declined or agreed to participate in a phase-III or phase-IV cardiac rehabilitation programme.
• Sufficient English language skills to understand and participate in an interview discussion.
• Over 18 years of age.
• Identified significant other provides informed consent to participate in the study.

Patient Exclusion Criteria for Interview Component of Study:

- Identified significant other refuses to participate or provide informed consent.

Significant Other Inclusion Criteria for Interview Component of Study:

• Nominated by the patient and willing to participate.
• Impacted or involved throughout the period of the patient's cardiovascular complication and recovery (e.g. familial relation, co-habitant, or close-relationship).
• Sufficient English language skills to understand and participate in an interview discussion.
• Over 18 years of age.
• Patient provides informed consent to participate in the study.

Significant Other Exclusion Criteria for Interview Component of Study:

- Patient refuses to participate or provide informed consent.

Post-myocardial infarction coronary artery disease patients who have been invited to participate in a phase-III cardiac rehabilitation programme with the Belfast Health and Social Care Trust or South Eastern Health and Social Care Trust.