TIME-COURSE OF CYTOKINE RELEASE AND COMPLEMENT ACTIVATION AFTER IMPLANTATION OF THE HEARTMATE LEFT-VENTRICULAR ASSIST DEVICE

Pro-inflammatory mediators, including interleukin-6 (IL-6), IL-8, and complement C3a, are released after cardiac surgery as part of the infl ammatory response related to blood-biomaterial interaction in the card iopulmonary bypass circuit. Post operative time course data for these mediators are not fully defined in patients receiving left ventricular assist device (LVAD) support. The authors performed enzyme linked imm unosorbent assays for concentrations of IL-6, IL-8, and C3a in plasma in six HeartMate(R) LVAD recipients at the following times: pre operat ively; 4, 8, 16, 24, 36, and 48 hr post operatively; daily through the first week; and weekly thereafter for 6 weeks. All patients survived without major complications during the study. Pre operative concentrat ions of IL-6 and C3a in plasma were significantly increased compared w ith age matched controls. Post operatively, the concentrations of IL-6 and IL-8 in plasma took longer to return to baseline values after ins ertion of the LVAD than the trends reported in the literature after ro utine cardiopulmonary bypass alone. Concentrations of IL-6 and complem ent C3a continued to decrease to lower than baseline post operatively, reaching statistical significance after 6 weeks of LVAD support. The authors conclude that the presence of the HeartMate LVAD delays the re turn of pro-inflammatory mediator concentrations back to baseline valu es compared with routine cardiopulmonary bypass alone, but the device does not appear to be an ongoing source of cytokine release or complem ent activation.