The endothelium - the cardiovascular health barometer

Once considered to fulfill no other purpose than that of a physical barrier between blood and tissue, the multifunctional nature of the endothelium was discovered in the later half of the 20th century. In cardiology, the dysfunctional nature of the endothelium has received even more attention, initially mainly within the research community but later also in the clinical community, serving as a prime example for the translation of bench research to patient care. In this review, the entity of endothelial dysfunction, its modes of diagnosis in clinical practice, its prognostic implications, and its treatment options will be defined. From past conceptual ideas to current practical applications to the road ahead, the endothelium is to be viewed as the cardiovascular health barometer.