Acute myocardial infarction is generally caused by a thrombotic occlusion of coronary arteries. Primary aim of early therapy is a fast and complete reperfusion of the infarcted myocardium, which can be achieved by either thrombolytic therapy or primary PCI.

Primary PCI is facilitated if the flow in the target vessel is restored prior to the intervention. In addition the results of recent trials hint that clinical outcome is improved by a patent infarct-vessel before primary PCI. The CIPAMI-study analyses the effect of an early administration of Clopidogrel on the flow-rates in subjects who suffered an acute myocardial infarction. For this purpose they are divided into two groups, both receiving standard baseline treatment. The subjects of one group additionally receive 600mg of Clopidogrel, as early as possible, while the subjects in the second group receive standard therapy. In the second group Clopidogrel is not allowed before initial angiography.

In both groups the flow-rates before and after PCI are analysed and compared in order to evaluate the efficacy, feasibility, and safety of the administration of a high loading dose Clopidogrel in the very early phase of STEMI in the prehospital setting.