Under-diagnosis of diabetes mellitus in patients with coronary artery disease.

BACKGROUND: The uptake of medical treatment in patients with coronary artery disease may be suboptimal. Our intention was to review the medical treatment of these patients in the light of current evidence. METHODS: One hundred ninety six consecutive patients with known or suspected coronary artery disease attending a tertiary centre for day case cardiac catheterisation were assessed. Fasting blood samples were sent for glucose and cholesterol. The results of coronary angiography and left ventriculography and any changes in medications were noted. RESULT: One hundred eighty two patients (93%) had fasting blood samples taken. The management of cholesterol in patients with coronary artery disease has improved since 1994. We have demonstrated the benefit of taking fasting blood samples in patients attending for day case angiography: 10% of non-diabetics actually had fasting blood glucose levels of greater than 7.0 mmol/l. All of these newly diagnosed diabetics had coronary artery disease. A further 9% of non-diabetics had impaired fasting glycaemia; 69% had coronary artery disease and 8% had left ventricular dysfunction. Among patients with coronary artery disease, there was a statistically significant increase on most categories of medications on discharge compared to admission. For those with left ventricular dysfunction, there was a statistically significant increase in the use of Angiotensin-Converting-Enzyme (ACE)-inhibitors. CONCLUSION: Diabetes mellitus is under-diagnosed in patients with coronary heart disease. They are at higher risk of coronary artery disease and therefore need intensive management. Testing all patients attending for day case cardiac catheterisation for fasting glucose would enable diagnosis and initiation of treatment of a high-risk group.