Neurological Complications After Cardiac Surgery: Risk Factors and Correlation to the Surgical Procedure[1]

Abstract

Objective: The aim of our study was to analyze risk factors for neurological complications in a group of patients undergoing cardiac operations. Methods: We analyzed 783 consecutive patients undergoing cardiac surgery in 2001. Group I consisted of 582 patients with a CABG procedure, group II patients underwent a single valve replacement (n = 101), group III had a combined procedure (CABG + valve) (n = 70), and group IV patients underwent multi-valve procedure (n = 30). Forward stepwise multiple logistic regression analysis was used for statistical evaluation of independent risk factors for neurological complications (reversible deficits and strokes). Results: The incidence of perioperative neurological problems was 1.7 % in the CABG group, 3.6 % in group II, 3.3 % in group III, and 6.7 % in group IV. With multivariate analysis we could identify various parameters as independent risk factors: previous neurological events, advanced age, and the time of aortic cross-clamping correlated with the incidence of perioperative neurological complications. In addition, we found a predictive value for preoperative anemia, the number of bypasses, an ejection fraction < 0.35 and for insulin-dependent diabetes mellitus. The duration of extracorporeal circulation and the fact of an re-operation could not be identified as risk factors. Conclusion: Our results show that type of surgery, symptomatic cerebrovascular disease, advanced age, diabetes mellitus, and probably aortic atheroma represent the most important risk factors for neurological complications. After preoperative consideration of the individual risk of each patient, neuroprotective interventions (arterial line filtration, alpha-stat management) and pharmacological neuroprotection may offer an improved outcome to some of these “high-risk” patients.

Neurological complication - open heart surgery - cerebrovascular disease - risk-stratification

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1 The results of this paper were presented in part during the 4th joint meeting of the Austrian, Swiss and German Society of Thoracic and Cardiovascular Surgery in Hamburg, Germany, February 15 - 18, 2004