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Postoperative cognitive decrease (POCD) represents the most frequent complication in modern cardiac surgery. The application of easily assessable surrogate parameters that predict long-term POCD at early time points is tempting. The aim of the present study was to analyze the predictive value of cerebral biomarkers, diffusion-weighted magnetic resonance imaging (DWI), and cognitive bedside testing after coronary artery bypass grafting (CABG). From 106 patients who underwent elective CABG, blood samples were drawn for the measurement of protein S100B and neuron-specific enolase release at baseline, at the end of surgery, and 48 hours afterward. Cerebral DWI was carried out before and 2 to 4 days after surgery. Cognitive functioning was assessed before, 2 to 4 days (bedside testing) after, and 3 months after CABG. On DWI, lesions were detected in 15.1% of patients. Biomarker levels and the presence of acute ischemic lesions on DWI were not associated with long-term POCD. Early POCD was correlated with 3-month POCD (r = 0.46, p0.001). Ninety-one percent of patients who had shown moderate to severe POCD (-1.5 z scores) in the early phase still had decreased memory functioning at 3 months compared to baseline (likelihood ratio 5.23). Early POCD was asserted as the only predictor for long-term POCD in a stepwise multiple linear regression model (R(2) = 0.20, p0.001), excluding age, length of surgery, aortic clamping and cardiopulmonary bypass duration, the number of anastomoses, and postoperative neuron-specific enolase and S100B levels. In conclusion, the results show that in contrast to biomarkers, DWI, age, or intraoperative variables, early neuropsychological bedside testing predicts long-term POCD after CABG with acceptable accuracy.

Aims The purpose of the study was to investigate whether intra-operative filter devices protect the brain during coronary artery bypass grafting (CABG) and to determine the impact of solid and gaseous micro-emboli on neuropsychological functioning. Methods and results Patients undergoing CABG received either an intra-aortic filter (Embol-X) ( n = 43), designed to reduce solid micro-emboli, a dynamic bubble trap (DBT) ( n = 50), designed to reduce gaseous micro-emboli, or no additional device (control group) ( n = 50). Cognitive functioning was assessed before and 3 months after CABG. Micro-emboli signals (MES) were detected during surgery using transcranial Doppler (TCD) sonography. Cerebral magnetic resonance imaging (MRI) was carried out before and after surgery. Primary endpoint was the cognitive outcome of the filter groups compared with the controls. Analysis of covariance was performed using the post-operative cognitive test scores as continuous variables in covariance of the corresponding pre-operative scores. Secondary endpoints were the MES rates and the number of acute ischaemic lesions after CABG. Compared with the controls, cognitive functioning of the DBT group was better in executive functioning ( t = 2.525, P = 0.0065) and verbal short-term memory ( t = 2.420, P = 0.009). The Embol-X group did not perform better in any test. The total number of MES was lower in the DBT group (median 99, P = 0.0019), but not in the Embol-X group (median 162.5, P > 0.05), both compared with controls (median 164.5). After surgery, 17 patients displayed small ischaemic brain lesions on MRI with equal distribution between the groups. Conclusion Gaseous micro-embolization contributes to neuropsychological decline, which is measurable 3 months post-operatively. No filter device could protect the brain during CABG completely. However, the use of the DBT tends to improve the cognitive outcome after CABG. Gas filters are recommendable for neuroprotection during cardiac surgery.

From 1975 to 1990, a total of 110 patients were operated for complex cardiac malformations with impaired pulmonary artery perfusion using porcine valved right heart to pulmonary artery conduits. Twelve- to 30-mm porcine valved conduits (Hancock or Carpentier-Edwards) were implanted at the age of 4 weeks to 28 years (mean 4.3 years). The patients' body weights were 2.9-68 kg (mean 15.3 kg). Early mortality was 5.5% (six patients), late mortality was 12.7% (14 patients), and 90 patients could be included in this long-term follow-up (426 patient-years). So far, 41 of the conduits had to be exchanged 4 months to 15 years (mean 6.5 years) after the first implantation. Forty-nine of the conduits are still in place. At reoperation, 38 patients received an allograft; three patients, reoperated before 1982, had a second xenograft. The main reason for porcine conduit malfunction was degeneration and/or calcification of the valves. In 11 patients, however, with 12- and 14-mm conduits implanted at a mean age of 3.1 years, a reoperation was necessary after a mean time of 6.8 years because these children had "outgrown" the conduit and needed a bigger one. We conclude that even though allografts seem to be the conduit of choice for right ventricular outflow tract reconstruction, our clinical experience shows that porcine valved conduits can be used just as well since most of them function sufficiently well for as long as 5 to 10 years, and early valve failure is relatively rare.