Ambulance diagnosis of ST elevation myocardial infarction eligible for primary PCI

Reperfusion therapy for ST-elevation acute coronary syndromes aims at early and complete recanalisation of the infarct-related artery in order to salvage myocardium and improve both early and late clinical outcomes. The benefit rises exponentially the earlier therapy is initiated. The greatest number of lives saved is within the first hour after symptom onset: the golden hour. The exponential form of the curve relating mortality to time-to-reperfusion has major implications for the timing of treatment. The impact of delay in time-to-treatment lessens as the duration of ischaemia lengthens. Consequently, reducing delays will have a much more positive return in patients presenting early than for those presenting late.