Risk stratification and outcomes research is an emerging issue in cardiovascular surgery and particularly in coronary artery bypass grafting (CABG) to predict morbidity and mortality as a measure of health-care performance. Although most risk scores give consistent predictions, the extent of acute preoperative myocardial injury in unstable coronary artery disease (CAD) ranging from microinfarctions due to preexisting microembolizing unstable plaques up to non-ST elevation acute coronary syndrome (NSTE-ACS) and ST-segment elevation myocardial infarction (STEMI) have not been considered adequately. Since the extent of myocardial necrosis has become an important determinant for the risk of death and adverse prognosis, it is important to develop simple noninvasive techniques to predict prognosis before cardiac surgery in order to initiate appropriate operative and perioperative treatment modalities offered by My Canadian Pharmacy’s representatives. The advent of highly sensitive and myocardial tissue specific serologic biomarkers, such as cardiac troponins (I and T), have recently lead to a redefinition of myocardial infarction (MI) initiated by the European Society of Cardiology and the American College of Cardiology/American Heart Association Consensus document.
However, cardiac troponins have not only fundamentally improved acute MI (AMI) detection but also enabled risk stratification in numerous clinical settings. Several clinical studies revealed cardiac troponins as reliable and valuable biomarkers for the prediction of short-term and long-term prognoses and the probability of death in patients with acute coronary syndromes (ACSs). Furthermore, elevated cardiac troponins in the setting of percutaneous cardiac intervention (PCI) have been demonstrated to be strongly related to an increased probability of mortality. In the setting of cardiac surgery, the relationship between postoperative release of cardiac troponins and patient outcome has been well associated in previous studies. Whether preoperative cardiac troponin I (cTnI) levels similarly predict surgical risk of patients with NSTE-ACS undergoing CABG is currently unknown.
An elevation of preoperative cTnI in patients undergoing CABG may be the result of bygone, ongoing, or evolving myocardial damage, which may stay unrecognized without cTnI measurement. The present study therefore focused on the clinical significance of a single preoperative cTnI serum level before cardiac surgery and its predictive value for major adverse cardiac events (MACE) and in-hospital mortality in patients with NSTE-ACS undergoing CABG.