A patient with undiagnosed diabetes and coronary artery disease

November 4, 2008
Cardiology Review® Online, May 2006, Volume 23, Issue 5

A 68-year-old man with increasing shortness of breath during moderate physical exertion consulted his family physician.

A 68-year-old man with increasing shortness of breath during moderate physical exertion consulted his family physician. The patient was obese (weight, 96 kg; height, 178 cm) and had had arterial hypertension for several years. He had had a stroke 2 years earlier. He was referred to a cardiologist.

The patient’s electrocardiogram showed signs of an old anterior wall infarction; however, he did not recall any specific cardiac symptoms in the past. An echocardiogram showed significantly restricted left ventricular pump function. Coronary angiography showed distinct 3-vessel coronary disease. The patient was scheduled for cardiac surgery, with the indication of elective coronary revascularization.

The preoperative laboratory values showed increased triglyceride levels, decreased high-density lipoprotein cholesterol levels, moderately in­creased leukocyte and C-reactive protein levels, and increased creatinine and urea retention values. Following a minimum fasting period of 10 hours, the plasma glucose level measured on the morning of the operation was 156 mg/dL. Both internal thoracic arteries were used in the revascularization procedure. To keep the postoperative trauma and risk of postoperative wound infection to a minimum, both arteries were skeletonized. Using T-graft anastomosis, the 4 revascularization targets (left anterior descending artery, diagonal artery, obtuse marginal artery, and posterior descending coronary artery) were reached via arterial bypasses. Immediately after the operation, the plasma glucose level was maintained within the normal range by administering continuous insulin infusions. The patient was placed on intensified insulin therapy on the third postoperative day.

The patient had increased creatinine and urea levels in the early postoperative period, and he developed anuria and acute renal failure on the second postoperative day. Renal function returned after hemodialysis, and the creatinine and urea retention values decreased with adequate volume substitution.

The patient was transferred to a rehabilitation clinic that specialized in the care of patients with diabetes. There, he was diagnosed with micro­vascular complications (nephropathy, neuropathy, and retinopathy), and his antiglycemic therapy was adjusted. The patient also received diabetes education, including nutritional counseling, and he learned how to determine his exercise tolerance limits under medical supervision. An HMG-CoA reductase inhibitor and angio­tensin-converting enzyme inhibitor were added to his medication regimen, which had consisted of only a beta blocker and aspirin before the operation. Following discharge from the rehabilitation center, the patient continued outpatient care with a diabetologist.