Relationship between Pre-Implant Interleukin-6 Levels, Inflammatory Response, and Early Outcome in Patients Supported by Left Ventricular Assist Device: A Prospective Study

PURPOSE: The immune response is crucial in the development of multi-organ failure (MOF) and complications in end-stage heart failure patients supported by left ventricular assist device (LVAD). However, at pre-implant, the association between inflammatory state and post-LVAD outcome is not yet clarified. Aim of the study was to assess the relationship among pre-implant levels of immune-related cytokines, postoperative inflammatory response and 3-month outcome in LVAD-patients. METHODS: In 41 patients undergoing LVAD implantation, plasma levels of interleukin (IL)-6, IL-8, crucial for monocyte modulation, and urine neopterin/creatinine ratio (Neo/Cr), marker of monocyte activation, were assessed preoperatively, at 3 days, 1 and 4 weeks post-LVAD. MOF was evaluated by total sequential organ failure assessment (tSOFA) score. Intensive care unit (ICU)-death and/or post-LVAD tSOFA ≥11 was considered as main adverse outcome. Length of ICU-stay, 1 week-tSOFA score, hospitalisation and 3-month survival were considered additional end-points. RESULTS: During ICU-stay, 8 patients died of MOF, while 8 of the survivors experienced severe MOF with postoperative tSOFA score ≥11. Pre-implant level of IL-6 ≥ 8.3 pg/mL was identified as significant marker of discrimination between patients with or without adverse outcome (OR 6.642, 95% CI 1.201-36.509, p = 0.030). Patients were divided according to pre-implant IL-6 cutoff of 8.3 pg/ml in A [3.5 (1.2–6.1) pg/mL] and B [24.6 (16.4–38.0) pg/mL] groups. Among pre-implant variables, only white blood cells count was independently associated with pre-implant IL-6 levels higher than 8.3 pg/ml (OR 1.491, 95% CI 1.004–2.217, p = 0.048). The ICU-stay and hospitalisation resulted longer in B-group (p = 0.001 and p = 0.030, respectively). Postoperatively, 1 week-tSOFA score, IL-8 and Neo/Cr levels were higher in B-group. CONCLUSIONS: LVAD-candidates with elevated pre-implant levels of IL-6 are associated, after intervention, to higher release of monocyte activation related-markers, a clue for the development of MOF, longer clinical course and poor outcome.