Primary percutaneous coronary intervention (pPCI) is the preferred treatment in ST elevation myocardial infarction (STEMI). The infarct-related artery (IRA) can be opened in more than 90% of the patients. However, STEMI patients still end up with a persistent perfusion defect of highly variable magnitude indicating that adjunctive treatment may add further protection against tissue damage. Ischemic preconditioning (IPC) is an intervention by which myocardium threatened by ischemia is exposed to short and repeated sublethal ischemic episodes prior to sustained ischemia (local IPC). A systemic response with protection of more remote organs (remote IPC (rIPC)) also can be induced. We have recently found that the infarct reducing effect can be obtained by obstruction of an extremity even though the remote stimulus is initiated during sustained occlusion of a coronary artery, the so-called remote preconditioning (rPerC). The clinical perspective is now to examine if rPerC can reduce the infarct size in patients with unpredictable ischemia in ST elevation myocardial infarction (STEMI). We perform a randomized study where patients en route for pPCI are allocated to either rPerC or a standard treatment to evaluate whether the tissue damage can be reduced. Effect measure will be infarct size determined by scintigraphy (final infarct size and salvage).