C-Reactive protein and inflammatory response associated to neurocognitive decline following cardiac surgery

Background: It has been recognized that neurocognitive decline (NCD) often occurs as a complication in cardiac surgery. The early inflammatory response and C-reactive protein (CRP) was examined in relation to NCD and to a marker of axonal central nervous system (CNS) injury after cardiopulmonary bypass. Methods: A cohort of patients undergoing coronary artery bypass grafting and/or valve procedures using cardiopulmonary bypass were administered a neurocognitive battery preoperatively and postoperatively at 6 hours and day 4. CRP, interleukin 1β, and interleukin 10 were quantified from serum. Increase of serum tau protein after surgery was used as a marker of axonal CNS damage. Results: The rate of NCD was found to be 40.5% in this group. Surprisingly, known predictors of NCD did not differ significantly between patients with/without NCD. Patients with NCD had an early increase of CRP of a significantly higher magnitude than those without NCD (38.01 ± 11.4 vs 16.49 ± 3.5 mg/L, P = .042), interleukin 1ß (2.35 ± 0.3 vs 1.20 ± 0.2 pg/mL, P = .002), and interleukin 10 (29.77 ± 4.7 vs 12.94 ± 2.2 pg/mL, P < .001). Increase in serum Tau protein was significantly correlated to NCD (r = 0.50, P = .02). Conclusion: Perioperative increases in CRP and inflammatory cytokines are associated with NCD in patients after cardiopulmonary bypass. Thus, it appears that inflammation plays a key role in NCD pathophysiology, likely via axonal CNS injury, and could become a target for prevention.