High-intensity Interval Training in Patients With Post-acute Coronary Syndrome

Inclusion criteria

• Males or females aged ≥ 18 years
• Acute coronary syndrome within 6 weeks (unstable angina, or non-ST elevation myocardial infarction (NSTEMI), or ST elevation myocardial infarction (STEMI with the presence of 2/3 criteria (i.e. typical chest pain, electrocardiographic ischemic change or elevated troponin T
• Complete revascularization defined as no major epicardial coronary artery or bypass graft with a residual diameter stenosis >50% and no residual left main stenosis ≥40%
• Left ventricular ejection fraction >40%
• Stable doses of medication during the 4 weeks prior to enrolment (STEMI patients must be on a stable dose of beta-blocker)
• Able to perform a maximal cardiopulmonary exercise test, 7) capacity and willingness to sign informed consent.

Exclusion criteria

• Recent coronary bypass surgery (<6 months)
• Incomplete revascularisation, left ventricular ejection fraction <40%
• Significant valvular disease (mitral stenosis, moderate to severe mitral insufficiency, aortic stenosis, or aortic insufficiency)
• Uncontrolled hypertension (systolic blood pressure/diastolic blood pressure >180/110 mmHg)
• Significant resting electrocardiogram abnormalities (left bundle branch block, non-specific intraventricular conduction delay, left ventricular hypertrophy, resting ST-segment depression)
• Chronic atrial fibrillation
• Pacemaker or implantable cardioverter defibrillator
• Low functional capacity (<5 basal Metabolic Equivalent of Task [METs])
• Change of cardiac medications within 4 weeks of enrolment and any contraindication to exercise testing or exercise training.