Increased mortality after an acute heart failure episode: new pathophysiological insights from the RELAX-AHF study and beyond.

Acute heart failure (AHF) is one of the most common causes of hospital admission. Despite the very high short-term morbidity and mortality and high costs associated with the condition, little progress has been made toward an understanding of the complex mechanisms of AHF, and particularly the spike in mortality after AHF admission. This manuscript addresses certain hypotheses for the pathophysiology of increased mortality after an AHF episode, specifically exploring the role of neurohormonal and inflammatory activation, congestion, and end-organ damage occurring during the first hours and days of an AHF episode. The results of the recently published RELAX-AHF (Relaxin in Acute Heart Failure) study may hold the key to understanding these intricate mechanisms. In the study, congestion and end-organ damage, which were strongly associated with increased 180-day mortality, were relieved by early administration of serelaxin, which was also associated with reduction in 180-day mortality. Hence, it is possible that early treatment of AHF, including decongestion and prevention of damage to end organs, including kidneys, heart, and liver, is critical to preventing mortality in AHF. This may require a change in our strategic approach to the management of patients admitted with AHF, setting them apart from patients with chronic heart failure (HF), and developing specific treatment strategies for AHF patients beyond simply implementing therapies proven to be effective in chronic HF.