The final analysis considered the following variables: age, gender, smoking history, body mass index (BMI), diabetes mellitus, hypertension, dyslipidemia, COPD, history of myocardial infarction (MI), cardiopulmonary bypass time (CPB), intra-aortic balloon pump (IABP), left ventricular ejection fraction (LVEF), and preoperative use of drugs (beta-blockers, angiotensin-converting enzyme [ACE] inhibitors, statins, and aspirin). Here, ACE is linked to chronic obstructive pulmonary disease.