Prognostic value of preoperative cardiac troponin I in patients undergoing emergency coronary artery bypass surgery with non-ST-elevation or ST-elevation acute coronary syndromes

Background-Cardiac troponin I (cTnI) is a highly sensitive and specific biomarker which has been shown to predict patient outcome pre- and postoperatively following elective coronary artery bypass surgery (CABG). Whether preoperatively elevated cTnI levels similarly predict the outcome in patients undergoing emergency CABG with acute myocardial infarction ( AMI) is currently unknown. Methods and Results-A possible correlation between preoperative cTnI and in-hospital mortality and major adverse cardiac events ( MACE) was investigated in 57 patients with ST-elevation AMI (STEMI) in group 1 and 197 with Non-ST-elevation AMI (NSTEMI) in group 2, who were operated within 24 hours after onset of symptoms. Primary study end point was all-cause in-hospital mortality. Secondary end points were low cardiac output syndrome (LCOS) and hospital course. CTnI levels on admission were higher in group 1 compared with group 2 (7.1 +/- 1.8 versus 1.4 +/- 1.8 ng/mL; P < 0.001). Overall in-hospital mortality was higher in group 1 compared with group 2 (14.3 versus 4.1%; odds ratio [OR], 3.9, 95% confidence interval [CI], 1.3 to 12.3; P < 0.01). LCOS occurred in 16/57 (28.1%), and 18/197 (9.1%) patients, respectively ( OR, 3.9, 95% CI, 1.7 to 8.8; P < 0.001). Postoperative ventilation time, intensive care, and hospital stay were significantly longer in group 1 versus group 2. Multivariate logistic regression analyses revealed preoperative cTnI as the strongest independent predictor for in-hospital mortality (P < 0.001) and MACE (P < 0.001) in all AMI patients, regardless whether ST-elevation was included as an additional risk factor or not. Conclusions-Preoperative cTnI measurement before emergency CABG appears as a powerful and independent determinant of in-hospital mortality and MACE in acute STEMI and NSTEMI.