Revascularization Strategies for STEMI; The CMR Endpoint Study

Inclusion Criteria: * High risk ST elevation myocardial infarction evidenced by: ≥2 mm ST elevation in 2 anterior or lateral leads; or ≥2 mm ST elevation in 2 inferior coupled with ST depression in 2 contiguous anterior leads for a total ST deviation of ≥8 mm; or New left bundle branch block with at least 1 mm concordant ST elevation. * Multivessel CAD as evidenced by ≥1 significant (≥70% by visual assessment or FFR\<0.80 for 50-70% stenosis) stenosis in non-IRA. * Successful IRA-PCI with \<10% residual angiographic stenosis and TIMI III flow. * Written informed consent. Exclusion Criteria: * Age ≤ 18 years. * Prior coronary artery bypass graft (CABG) surgery. * Administration of thrombolytic therapy. * Non-IRA stenosis is a chronic total occlusion or located in left main artery. * Hemodynamic instability evidenced by BP\<90 mmHg, Killip class ≥2, need for inotropes/vasopressors. * Known renal insufficiency (estimated GFR \< 50ml/min). * Contraindication to CMR.