Current clinical management of acute myocardial infarction complicated by cardiogenic shock

Cardiogenic shock (CS) remains the leading cause of death among patients admitted with acute myocardial infarction (AMI). Early restoration of blood flow of the infarct-related artery is of paramount importance, either with percutaneous coronary intervention (PCI) or with coronary artery bypass grafting (CABG). In addition, early risk stratification is a critical task and required to guide complex decisions on management and therapy of CS after AMI. The use of short-term mechanical circulatory support (MCS) is increasing, although evidence for their effectiveness is limited.

We review the evidence for early revascularization of the culprit-lesion and risk stratification in patients with AMI complicated by cardiogenic shock. The current data for the use of MCS will be discussed and put into clinical perspective.

The SHOCK trial has introduced an early invasive strategy with subsequent revascularization as standard of care in patients with AMI complicated by CS. In clinical practice PCI is the by far the most often used revascularization therapy in CS. Most important is restoration of normal flow (so called TIMI 3 patency) of the infarct artery to reduce mortality. Therefore, all efforts including intense antithrombotic therapy should be made to achieve TIMI 3 patency. Around three quarters of patients with CS have multivessel coronary artery disease. According to the results of the CULPRIT-SHOCK trial PCI of the culprit lesion only is recommended as the preferred revascularization strategy in these patients, while additional lesions can be revascularized during a staged procedure. Immediate multivessel PCI could be performed in some specific angiographic scenarios, such as subtotal non-culprit lesions with reduced Thrombolysis In Myocardial Infarction (TIMI)-flow, or multiple possible culprit lesions. However, this should be considered on an individual basis. CABG should be performed only in case of failed PCI and coronary anatomies not suitable for PCI. However, small case series report good outcomes in selected patients with CS undergoing CABG. Therefore, a randomized trial comparing PCI and CABG in patients with CS and multivessel disease seems warranted. Hopefully such a trial will take place to determine the optimal revascularization therapy in CS. One problem might be to find a sufficient number of cardiac surgeons who are willing to operate such high-risk surgical patients.