The impact of diabetes or elevated fasting blood glucose on cardiovascular prognosis in patients with stable angina pectoris.

AIMS

To examine the influences of diabetes and elevated fasting blood glucose on cardiovascular prognosis in patients with stable angina pectoris.

METHODS

In a prospective study of 809 patients with stable angina pectoris randomized to receive metoprolol or verapamil, a subgroup of 69 diabetic patients was compared with non-diabetic patients with respect to the risk of cardiovascular (CV) death, non-fatal myocardial infarction (MI) and revascularization. We also analysed a subgroup of 67 patients with fasting blood glucose > or = 6.1 mmol/l, defined according to the most recent revised guidelines for the diagnosis of diabetes mellitus. Fasting blood glucose was measured in venous whole blood at baseline.

RESULTS

The diabetic patients had a greater risk-factor burden, with a higher prevalence of hypertension, more likely to be male, a tendency towards a higher prevalence of previous MI, and higher triglyceride and lower high-density lipoprotein (HDL)-cholesterol levels. In multivariate analyses, diabetes was an independent risk factor for CV events with a relative risk of 2.64 (CI 1.39-5.00; P < 0.001) for CV death/MI, and 1.79 (CI 1.02-3.15; P < 0.01) for revascularization. Blood glucose > or = 6.1 mmol/l without a diagnosis of diabetes mellitus was found in 67 patients, and predicted CV death/MI [relative risk 2.76 (CI 1.97-3.84)] in both univariate and multivariate analyses. The prognosis of diabetic or hyperglycaemic patients did not differ significantly with metoprolol compared with verapamil treatment.

CONCLUSIONS

Diabetes mellitus is an independent risk factor for CV death/MI and for revascularization in patients with stable angina pectoris. Elevated fasting blood glucose was seen in 9% of patients without known diabetes and was an equally strong and independent risk factor for CV death/MI as diagnosed and treated diabetes.