Currently, coronary artery bypass grafting (CABG) is the most effective and prevalent method of treatment of ischemic heart disease. CABG can also be performed to high risk patient with multiple systemic problems. In order to determine the risk factors which affect the mortality and morbidity in coronary bypass surgery, the medical records of 1250 patients who underwent CABG in our clinic since 1990 were reviewed.

In these patients, preoperative variables such as age, sex, unstable angina, myocardial infarction, left ventricle ejection fraction; operative variables such as number of distal anastomoses, cardiopulmonary bypass (CPB) and cross-clamp times, peroperative myocardial infarction; postoperative variables such as respiratory, renal and heart failure, bleeding and infection were evaluated to predict the possible risk factors.

Statistical analysis revealed that the predictors of mortality were age over 60, unstable angina, ejection fraction of less than 40%, more than four distal anastomoses, longer than 90 minutes cross-clamp time, longer than 120 minutes CPB time, peroperative myocardial infarction for mediastinitis and bleeding.

Predictors of left ventricular failure were age over 60, unstable angina, ejection fraction less than 40%, more than four distal anastomoses, longer than 90 minutes cross-clamp time, longer than 120 minutes CPB time, peroperative myocardial infarction, renal and respiratory failure reexploration for mediastinitis.

Risk factors for respiratory failure were age over 60, chronic obstructive pulmonary disease, peroperative myocardial infarction, renal and left ventricular failure.