High output heart failure: A review of clinical status - epidemiology, pathophysiology, diagnosis, prognosis and clinical management

The clinical syndrome of heart failure (HF) has traditionally been associated with low or normal cardiac output accompanied by increased systemic vascular resistance. This association has led to the present under-appreciation of a minority group of HF patients presenting with high cardiac output but with normal cardiac function, clinically termed high-output HF. In these patients, the pathophysiological hallmark is decreased systemic vascular resistance. Because these patients lack proven therapies, treatment relies on evidence-based therapies developed for low-cardiac output HF. With a paucity of clinical trial data, evidence based from case reports suggest some of the established HF medications such as vasodilators and inotropes can be potentially detrimental for patients with high-output HF. These findings demonstrates an unmet clinical need for in-depth understanding of the pathophysiology, aetiology and clinical course of high-output HF, which forms the basis for the present review.