Kidney in acute heart failure

The hallmark of symptomatic heart failure (HF) is sodium and water retention, leading to congestion and symptoms of edema. Indeed, Starling in the 19th century asked provocatively, What, if anything, does the heart have to do with heart failure? He also advanced the theory that humors must be released in HF that lead to leakiness of capillaries and edema formation, a concept that is not opposed to our current understanding of the complex activation of diverse neurohumoral systems that characterize symptomatic HF and contribute to renal dysfunction. Key epidemiologic studies have refocused our attention on the role of the kidney in this syndrome, as they have established that renal dysfunction is one of the most robust predictors of mortality and morbidity in the setting of ventricular dysfunction and HF. Specifically, in two retrospective analyses, impaired renal function was identified as a major predictor of mortality in human HF, more powerful even than New York Heart Association (NYHA) class or left ventricular ejection fraction.1,2