Increased S100B in blood after cardiac surgery is a powerful predictor of late mortality

Background Long-term outcome in patients who suffered stroke after undergoing a cardiac operation has been investigated sparingly, but increased long-term mortality has been reported. S100B is a biochemical marker of brain cell ischemia and blood–brain barrier dysfunction. The aim of this investigation was to record the long-term mortality in consecutive patients undergoing cardiac operations and to explore whether increased concentrations of S100B in blood had a predictive value for mortality. Methods Prospectively collected clinical variables, including S100B, in 767 patients who survived more than 30 days after a cardiac operation, were analyzed with actuarial survival analysis and 678 patients were analyzed with Cox multiple regression analysis. Results Forty-nine patients (6.4%) were dead at follow-up (range, 18 to 42 months); 11.5% (88 of 767 patients) had elevated S100B 2 days after operation (range, 38 to 42 hours). The probability for death at follow-up was 0.239 if the S100B level was more than 0.3 μg/L, and 0.041 if it was less than 0.3 μg/L. The clinical variables independently associated with mortality were preoperative renal failure, preoperative low left ventricular ejection fraction, emergency operation, severe postoperative central nervous system complication, and elevated S100B values, which turned out to be the most powerful predictor. Conclusions Even slightly elevated S100B values in blood 2 days after cardiac operation imply a bad prognosis for outcome, and especially so in combination with any central nervous system complication.