Cardiogenic shock (CS) complicating acute myocardial infarction (AMI) represents a major European health care concern with mortality rates between 40-70%. Approximately 70-80% of these patients present with multivessel disease defined as coronary lesions in more than one vessel. The clinician is faced with the decision to either 1) intervene only on the culprit lesion acutely responsible for the initiation of cardiogenic shock, or 2) treat additional lesions considered hemodynamically significant but not acutely triggering the CS cascade as well. Current guidelines recommend percutaneous coronary intervention of all critical lesions. However, due to a lack of randomized trials, these recommendations are solely based on registry data and pathophysiological considerations. Aim of the randomized CULPRIT-SHOCK trial is therefore to compare a) immediate multivessel PCI versus b) culprit lesion only PCI in patients with AMI complicated by CS. A total of 706 CS patients will be randomized in several European countries. The primary endpoint will be 30-day all-cause mortality and/or severe renal failure requiring renal replacement therapy. CULPRIT-SHOCK will therefore determine the optimal percutaneous revascularization strategy in patients with AMI and multivessel disease complicated by CS. In addition, a comprehensive array of efficacy, safety and socio-economic parameters for the chosen population will be assessed. Multiple secondary endpoints and several substudies (microcirculation, biomarkers, angiography) will serve to further understand the presumed differential effects of the 2 treatment arms and to understand the underlying pathophysiology and prognostic markers. From these parameters a multivariable regression model and a risk score for the prediction of clinical prognosis and a cost-effectiveness model in AMI and CS will be developed. Furthermore, CULPRIT-SHOCK will obtain data on CS patients not meeting inclusion criteria by instituting a separate registry.