Current evidence in the diagnosis and management of cardiogenic shock complicating acute coronary syndrome

Cardiogenic shock (CS) is a hemodynamically complex and highly morbid syndrome characterized by circulatory collapse and inadequate end-organ perfusion due to impaired cardiac output. It is usually associated with multiorgan failure and death. Mortality rate is still high despite advancement in treatment. CS has been conceptualised as a vicious cycle of injury and decompensation, both cardiac and systemic. Interrupting the vicious cycle and restoring the hemodynamic stability is a fundamental treatment of CS. Acute coronary syndrome (ACS) is the most frequent cause of CS. Early coronary revascularization is a cornerstone therapy that reduces mortality in patients with ACS complicated by CS. Early diagnosis of CS accompanied with invasive hemodynamics, helps in identification of CS phenotype, classification of CS severity, stratification of risk and prognostication. This can guide a tailored and optimized therapeutic approach. Inotropes and vasopressors are considered the first-line pharmacological option for hemodynamic instability. The current availability of the mechanical circulatory support devices has broadened the therapeutic choices for hemodynamic support. To date there is no pharmacological or nonpharmacological intervention for CS that showed a mortality benefit. The clinical practices in CS management remain inconsistent. Herein, this review discusses the current evidence in the diagnosis and management of CS complicating ACS, and features the changes in CS definition and classification.