Prognostic value of admission glucose and glycosylated haemoglobin levels in acute coronary syndromes

Background: Admission hyperglycaemia is associated with poorer prognosis in patients with an acute coronary syndrome (ACS). Whether hyperglycaemia is more important than prior long-term glucose metabolism, is unknown. Aim: To investigate the prognostic value of admission glucose and HbA(1c) levels in patients with ACS. Methods: We measured glucose and HbA(1c) at admission in 521 consecutive patients with suspected ACS. Glucose was categorized as < 7.8 (n = 305), 7.8-11.0 (n = 138) or >= 11.1 mmol/l (n = 78); HbA(1c) as < 6.2% (n = 420) or >= 6.2% (n = 101). Mean follow-up was 1.6 +/- 0.5 years. Results: The diagnosis of ACS was confirmed in 332 patients (64%), leaving 189 (36%) with atypical chest pain. In ACS patients, mortality by glucose category (< 7.8, 7.8-11.0 or >= 11.1 mmol) was 9%, 8% and 25%, respectively (p = 0.001); mortality by HbA(1c) category (< 6.2% vs. >= 6.2%) was 10% vs. 17%, respectively (p = 0.14). On multivariate analysis, glucose category was significantly associated with mortality (HR 3.0, 95%CI 1.1-8.3), but HbA(1c) category was not (HR 1.5, 95%CI 0.6-4.2). Discussion: Elevated admission glucose appears more important than prior long-term abnormal glucose metabolism in predicting mortality in patients with suspected ACS.