Cardiogenic Shock in Patients with Advanced Chronic Heart Failure.

Patients with end-stage heart failure (HF) who have failed optimal medical therapy provide a unique set of challenges compared to the more prevalent population of patients with cardiogenic shock (CS) due to ST-segment elevation myocardial infarction. Progression from "preshock" into a refractory state of CS is associated with a dismal outcome due to difficulties with the patient's recognition, response to interventions, and candidacy for salvage options. Challenges include heterogeneity of CS (eg, different phenotypes, etiologies, duration, acuity of onset, hemodynamics, end-organ effects), lack of a universal definition of CS that is applicable to this patient population, and blunted hemodynamic response given the patient's prolonged compensatory state. Individuals with advanced HF in CS require a multidisciplinary team-based assessment regarding when to escalate from medical therapy into temporary mechanical circulatory support, and they need an eligibility evaluation to determine their candidacy for advanced therapy. In this review, we discuss the definition and clinical phenotypes of CS, classification of CS in advanced HF patients, the utility of temporary mechanical circulatory support, and the role of the CS team.