Admission glycaemia and outcome after acute coronary syndrome

Background Acute phase hyperglycaemia has been associated with increased mortality in patients with acute coronary syndrome. We investigated whether the predictive value of admission hyperglycaemia for mortality differs between diabetics and non-diabetics with acute coronary syndrome. Methods Patients with acute coronary syndrome (n = 1957) were followed up prospectively for 45 months. Patients were stratified into quartile groups defined by admission plasma glucose and hyperglycaemia was defined as plasma glucose of > 9.4 mmol/l, which was the cut-off value for the 4th quartile. The relationship between admission hyperglycaemia and short-term (≤ 30 day) and late (> 30 day) mortality was analysed. Results Of 1957 patients, 22% had a history of diabetes. Among patients without diabetes, those with hyperglycaemia had both a higher 30-day mortality rate (20.2% vs. 3.5%, p < 0.0001) and late mortality rate (19.1% vs. 11.7%, p = 0.007). Hyperglycaemic patients with diabetes had a higher late mortality rate than diabetic patients with plasma glucose of ≤ 9.4 mmol/l (29.3% vs. 14.9%, p = 0.001). Of patients with hyperglycaemia at admission, those without diabetes had a higher 30-day mortality rate compared with those with diabetes (p = 0.002). Conclusion Admission hyperglycaemia is a strong risk factor for mortality in patients with acute coronary syndrome and may be even stronger than a previous history of diabetes. Hyperglycaemic patients without recognised diabetes have a higher short-term mortality risk than hyperglycaemic patients with known diabetes.