About a quarter of people having an acute myocardial infarction (MI) in the USA will die of it, half of them within 1 hour of the onset of symptoms. Cardiogenic shock develops in over 5% of people surviving the first hour after an acute MI, with a mortality of 50-80% in the first 48 hours.We conducted a systematic review and aimed to answer the following clinical questions: Which treatments improve outcomes in acute MI? Which treatments improve outcomes for cardiogenic shock after MI? We searched: Medline, Embase, The Cochrane Library, and other important databases up to August 2007 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).We found 50 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.In this systematic review we present information relating to the effectiveness and safety of the following interventions: angiotensin-converting enzyme (ACE) inhibitors, aspirin, beta-blockers, calcium channel blockers, early cardiac surgery, early invasive cardiac revascularisation, glycoprotein IIb/IIIa inhibitors, intra-aortic balloon counterpulsation, nitrates (with or without thrombolysis), positive inotropes, primary percutaneous transluminal coronary angioplasty (PTCA), pulmonary artery catheterisation, thrombolysis (with or without low molecular weight heparin, with or without unfractionated heparin), vasodilators, and ventricular assistance devices and cardiac transplantation.