Myocardial infarction (ST-elevation)

Abstract

Introduction: About one 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% to 80% in the first 48 hours.

Methods and outcomes: 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 October 2009 (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).

Results: We found 52 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

Conclusions: 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.

Figure 1

The AMIS registry Kaplan–Meier survival curves as a function of Killip class at hospital admission for 3138 people (2901 evaluable) admitted in 50 Swiss hospitals between 1977 and 1998. Published with permission: Urban P, Bernstein MS, Costanza MC, et al, for the AMIS investigators. An internet-based registry of acute MI in Switzerland. Kardiovasc Med 2000;3:430–441 (see text).

Figure 2

Absolute effects of antiplatelet treatment on outcomes in people with a prior suspected or definite acute MI. The columns show the absolute risks over 1 month for each category; the error bars are the upper 95% CI. In the "any death" column, non-vascular deaths are represented by lower horizontal lines. The table displays for each outcome the absolute risk reduction (ARR), the number of people needing treatment for 1 month to avoid one additional event (NNT), and the risk reduction (RR), with their 95% CI values (see text). Published with permission.

Figure 3

Absolute number of lives saved at 1 month/1000 people receiving thrombolytic treatment plotted against the time from the onset of symptoms to randomisation among 45,000 people with ST-segment elevation or bundle branch block. Numbers along the curve are the number of people treated at different times (see text). Published with permission: Collins R, Peto R, Baigent BM, et al. Aspirin, heparin and fibrinolytic therapy in suspected AMI. N Engl J Med 1997;336:847–860. Copyright © 1997 Massachusetts Medical Society. All rights reserved.