An asymptomatic 65-year-old woman with a 10-year history of well-controlled diabetes mellitus, hyperlipidemia, and hypertension was referred for preoperative cardiac evaluation before noncardiac surgery. She denied a history of myocardial infarction, renal disease, or smoking, as well as a family history of premature coronary artery disease. She had been clinically stable while receiving oral antidiabetic agents, an angiotensin-converting enzyme inhibitor, and statin therapy. Over the last few years, her physical activity was limited because of degenerative joint disease of the right knee, and total knee replacement was planned.

Results of the patient’s physical examination and electrocardiogram were normal. Mild cardiomegaly without pulmonary congestion was shown on radiography. Dobutamine (Dobutrex) stress echocardiography showed normal left ventricular systolic function at rest but was positive for inducible ischemia of the septum and anterior wall. The ischemic threshold was 70% of age-predicted maximal heart rate. The resting and peak wall motion index scores were 1.0 and 1.375, respectively. The percentage of ischemic segments was 37.5%. Because of the large area of ischemia, coronary angiography was performed and showed 90% discrete stenosis of the proximal left anterior descending artery. Subsequently, percutaneous coronary angioplasty with stenting was successfully performed with a good result. Six months later, the patient underwent uncomplicated total knee replacement.

According to our study, the risk score for this patient was 2, or intermediate, for mortality and 4, or high risk, for cardiovascular morbidity. The risk category was clinically useful and led to further evaluation and risk modification to improve the outcome, as illustrated in this case study.