Approximately 7.5 percent of all acute myocardial infarctions which are diagnosed in an emergency room or in-hospital lead to cardiogenic shock and an in-hospital death rate of 70 to 80 percent, usually within one to two days of diagnosis of cardiogenic shock. The high death rate has not changed in the last two decades. Non-random clinical series and animal studies suggest that rapid revascularization following cardiogenic shock complicating acute myocardial infarction may substantially improve survival. However, the apparent benefit reported in the non-random clinic studies could have resulted partly from a selection bias towards patients with a better prognosis.