In spite of high prevalence, congestion remains a poorly understood phenomenon in heart failure pathophysiology. Its negative impact on outcome has been widely recognised. Still, data from various registries reveal the failure of the contemporary treatment strategies to overcome congestion. This shortcoming is closely related to the fact that there are no universe means for congestion assessment and grading, making it a difficult process to recognise. CD146 is a novel blood biomarker of congestion that has been shown to reflect intravascular fluid accumulation in a number of experimental and clinical studies. This observation deserves special attention, given the huge gap of knowledge about decongestive strategies in acute and chronic heart failure. Randomised clinical trials testing the effect of CD146-guided management intervention are urgently needed to estimate its value in heart failure care.