We will be recruiting 3 different strata of STEMI patients.  Adult patients (≥18 years old) presenting with STEMI receiving thrombolytic therapy within guideline-recommended time (i.e., within <12 hours of most severe chest pain onset). Adult patients (≥18 years old) presenting with STEMI who are ineligible for thrombolysis because they present outside of guideline-recommended time (<12 hours) but within 24 hours of most severe chest pain onset. Adult patients (≥18 years old) presenting with evidence of STEMI who do not receive thrombolysis and who present ≥24 hours and within 72 hours of most severe chest pain onset.  Interventional arm of the Study: Randomized Control Trial  Patients who are deemed eligible for randomization into the trial on account of presentation with STEMI within 24 hours, will be eligible for the interventional arm of the study if the following inclusion/exclusion criteria are met.  Inclusion Criteria  I. Adult patients (≥18 years old) presenting with suspected STEMI (ST-elevation at the J-point in two contiguous leads ( ≥ 0.2mV in men or ≥ 0.15mV in women in leads V2-V3 and/or ≥ 0.1mV in other lead); and II. Within 24 hours of onset of myocardial infarction as deemed by the attending clinician; and III. Signed informed consent.  Exclusion criteria  I. STEMI patients due to undergo primary percutaneous coronary intervention;  II. STEMI patients presenting with cardiogenic shock or haemodynamic instability as defined by: systolic blood pressure (SBP) measurement of <90 mm Hg for ≥30 minutes; or use of pharmacological and/or mechanical support to maintain SBP ≥ 90 mm Hg; and evidence of end-organ damage defined by: urine output of <30 mL/h; altered mental status; and/or serum lactate >2.0 mmol/L;  III. Contraindications for the use of RIC or sham-control on either arm such as:  severe active skin disease/burns on both arms; or bilateral upper limb amputations; or evidence of acute limb ischaemia on either arm; or active upper limb gangrene of any digits; breast cancer with lymph-node involvement on the ipsilateral side of RIC; or bilateral arteriovenous fistulae needed for haemodialysis.  IV. Inter-current disease with an expected life expectancy of less than 24 hours;  V. Contra-indication to thrombolytic therapy in patients presenting within guideline-recommended time (<12 hours).  Observational arm of the study  Patients who are deemed ineligible for randomization into the trial on account of presentation beyond 24 hours, will be eligible for the observational arm of the study if the following inclusion/exclusion criteria are met.  Inclusion Criteria  I. Signed informed consent; and  II. Clinical evidence of STEMI older than 24 hours and less than 72 hours as defined by:  Compatible history with maximal chest pain between 24 -72 hours prior to presentation; and Compatible biomarkers (elevated cardiac troponin); and ECG compatible with recent STEMI; and/or Compatible echocardiography.  Exclusion criteria  I. Refusal or inability to sign informed consent.