Background: To objectively measure long-term neurocognitive deficit in patients undergoing coronary artery bypass grafting and compare the findings with nonsurgical controls.
Methods: We prospectively measured neurocognitive function in patients undergoing coronary artery bypass grafting (CABG) with cardiopulmonary bypass (n = 104; mean age 64.1 years old; EuroSCORE 2.7 [means]). A cohort of age- and sex-matched patients (n = 80; mean age 63.4 years old) served as nonsurgical controls. After CABG, neurocognitive function was serially reevaluated at 7-day (n = 104), 4-month (n = 100), and 3-year follow-up (n = 88). Neurocognitive function was objectively measured by means of cognitive P300 evoked potentials. Additionally, standard psychometric tests were performed (Trailmaking Test A, Mini Mental State Examination).
Results: As compared to preoperative measures (364 +/- 36 ms), cognitive P300 evoked potentials were prolonged (=impaired) at 7-day (381 +/- 36 ms; p = 0.001), 4-month (378 +/- 31 ms; p = 0.08), and 3-year follow-up (379 +/- 35 ms; p = 0.002), respectively. Trailmaking Test A was abnormal, as compared to preoperative, at 3-year follow-up (p < 0.001). Before the operation, surgical patients were fully comparable in P300 measures to nonsurgical controls (363 +/- 32 ms; p = 0.362). Most importantly, throughout the entire postoperative follow-up cognitive measures in surgical patients were prolonged (=impaired) as compared with controls (7-day p = 0.001; 4-month p = 0.002 and 3-year p = 0.003, respectively). In stepwise multivariate regression analysis, neurocognitive deficit at 4-month follow-up (p < 0.001), age (p = 0.012), and persistent atrial fibrillation (p = 0.024) were predictive for long-term neurocognitive deficit at 3-year follow-up.
Conclusions: As shown by means of objective measures, and in comparison to nonsurgical controls, coronary artery bypass grafting with cardiopulmonary bypass grafting causes long-term neurocognitive deficit.