Implantation of a Continuous-Flow Left Ventricular Assist Device During Cardiopulmonary Bypass Is Associated with a Significant and Transient Acute Thromboinflammatory Response

Left ventricular assist device (LVAD) implantation is a life-saving therapy for end-stage heart failure but may compromise immune integrity. Mechanical shear stress and surface-induced innate immune activation can trigger bleeding and thromboembolic complications. While thrombotic mechanisms are well characterized, the associated inflammatory response remains poorly studied. We investigated thromboinflammation in patients with terminal heart failure (n = 8) implanted with the HeartWare ventricular assist device. Blood samples were collected before and immediately after implantation, daily for five days, and three months post-implantation. Ten age- and sex-matched healthy individuals served as controls. Samples were analyzed for a broad panel of thromboinflammatory and cell damage biomarkers. Twenty-eight of 43 biomarkers were significantly elevated (p < 0.05) at patient baseline compared with controls, indicating a pre-existing low-grade inflammatory state prior to LVAD implantation. Complement activation products increased markedly immediately after implantation—C3bc, C3bBbP, and the terminal complement complex C5b-9 rose 2.8-, 8.9-, and 6.6-fold, respectively, compared with baseline (p < 0.0001), but returned toward baseline within 24 h. A similar transient increase was observed for TNF, IL-6, IL-8, IL-10, IFN-γ, MMP-8, MMP-9, tissue factor, and prothrombin fragment 1.2 (p < 0.05). LVAD implantation with cardiopulmonary bypass induces a strong but transient immune response, including robust complement activation. Targeting upstream complement pathways may help attenuate downstream thromboinflammatory processes during the acute post-implantation period.