Risk Factors for Delayed Neurocognitive Recovery According to Brain Biomarkers and Cerebral Blood Flow Velocity.

The aim of this study is to identify risk factors for the development of delayed neurocognitive recovery (dNCR). 140 patients underwent neurocognitive evaluations (Adenbrooke, MoCa, trial making, and CAM test) and middle cerebral artery (MCA) blood flow velocity (BFV) measurements, one day before cardiac surgery. BFV was re-evaluated after anesthesia induction, before the beginning, middle, end, and after cardiopulmonary bypass (CPB) and postsurgery. To measure glial fibrillary acidic protein (GFAP) and neurofilament heavy chain (Nf-H), blood samples were collected after anesthesia induction, 24 and 48 h after the surgery. Neurocognitive evaluation was repeated 7-10 days after surgery. According to the results, patients were divided into two groups: with dNCR (dNCR group) and without dNCR (non-dNCR group). 101 patients completed participation in this research. GFAP increased in both the non-dNCR group ( < 0.01) and in the dNCR group ( < 0.01), but there was no difference between the groups (after 24 h, 0.342; after 48 h, 0.273). Nf-H increased in both groups ( < 0.01), but there was no difference between them (after 24 h, = 0.240; after 48 h, = 0.597). MCA BFV was significantly lower in the dNCR group during the bypass (37.13 cm/s SD 7.70 versus 43.40 cm/s SD 9.56; = 0.001) and after surgery (40.54 cm/s SD 11.21 versus 47.6 cm/s SD 12.01; = 0.003). Results of neurocognitive tests correlated with CO concentration (Pearson's r 0.40, < 0.01), hematocrit (r 0.42, < 0.01), MCA BFV during bypass (r 0.41, < 0.01), and age (r -0.533, < 0.01). The probability of developing dNCR increases 1.21 times with every one year of increased age ( < 0.01). The probability of developing dNCR increases 1.07 times with a decrease of BFV within 1 cm/s during bypass ( = 0.02 : Risk factors contributing to dNCR among the tested patients were older age and middle cerebral artery blood flow velocity decrease during bypass.