Intraoperative sRAGE kinetics. A new age-related outcome predictor of cardiac surgery.

BACKGROUND: Glycated proteins (advanced glycation endproducts, AGE) in tissue are associated with degenerative diseases. This study evaluated the role of sRAGE (soluble receptor for advanced glycation endproducts), a decoy receptor of AGEs in blood, for the outcome of patients after coronary artery bypass grafting (CABG).

METHODS: A total of 90 patients undergoing CABG were analysed in two centres. Perioperative blood samples were collected before surgery up to 1 week postoperatively. sRAGE was measured by ELISA. Patients were subdivided regarding age (< 64 versus > 70 years, 14 % versus 35 % female), euroSCORE (< 3 versus > 4, 14 % versus 29 % female) and sRAGE changes between sternotomy and end of the operation (< 30 % versus > 45 %, 33 % versus 33 % female) and subsequently analysed with respect of postoperative outcome parameters.

RESULTS: Preoperative sRAGE values did not correlate with the outcome of the patients. sRAGE levels increase within 10 min from 1,539 ± 96 to 5,311 ± 187 pg/ml after sternotomy, then returning to baseline levels within 2 days after surgery. Comparing the analysed possible risk factors age, euroSCORE and sRAGE changes, no difference was observed regarding 30-day mortality. Age and the euroSCORE are superior with respect of tachyarrythmia, whereas sRAGE kinetics seems to be superior with respect of prolonged postoperative respiration time/stay in the intensive care unit or catecholamine support.

CONCLUSION: A prolonged, increased intraoperative sRAGE level is a new outcome predictor for patients undergoing CABG surgery, mutually complementary to the euroSCORE.