We enthusiastically read the paper by Poli et al. related to the use of CytoSorb® in high-risk cardiac surgery. While use of CytoSorb® showed no clinical or laboratory benefit, it was not associated with any complications either [1]. We noted the low level of interleukin-6 (IL-6) reported in this study (i.e., median values < 50 pg/ml and < 200 pg/ml during and after CBP). This observation may explain why there was no obvious benefit. In the paper by Träger et al., a series of 16 post-cardiac surgery patients with systemic inflammation (SI) characterized by a mixture of cardiogenic shock and distributive shock with acute kidney injury requiring continuous renal replacement therapy were enrolled. The authors observed patients prior to treatment with CytoSorb® to have baseline IL-6 and IL-8 levels between 500 and 10,000 pg/mL and 50 and 1000 pg/mL, respectively. Along with a decrease in the interleukin levels, hemodynamic parameters including cardiac index and mean arterial pressure improved and the need for catecholamine declined [2]. The same benefit was observed when CytoSorb® was used intraoperatively for patients with endocarditis. These patients had a high level of IL-6 and IL-8 prior to the intervention [3]. It is also reported that among septic patients with elevated IL-6 (> 1000 pg/mL) requiring continuous renal replacement therapy, cytokine clearance was more efficient when hemoperfusion and hemoadsorption were utilized [4]. Patients with a significant preoperative SI, such as in endocarditis or sepsis or with complicated surgery, are the most likely to benefit from CytoSorb® therapy. We agree with the authors that some cardiac surgery patients might benefit from hemoadsorption device, but we believe that the indication should be tested in patients with a high level of circulating cytokines—such as IL-6 [5].