In patients with an acute myocardial infarction, admission hyperglycaemia (AH) is a major risk factor for mortality. However, the predictive value of AH, when the risk score and use of guidelines-recommended treatments are considered, is poorly documented.
The first fasting plasma glucose levels after admission, risk level, guidelines-recommended treatment use and 1-year mortality were recorded. Patients with first fasting glucose level after admission > 7.7 mmo/l were considered to have AH.
Three hundred and twenty patients with ST segment elevation myocardial infarction (STEMI) and 404 with non-ST segment elevation myocardial infarction (NSTEMI) were included. One hundred and seventy-five (24%) patients had pre-existing diabetes (diabetes group), 154 (21%) had AH (AH+ group) and the remainding 395 (55%) had neither diabetes nor AH (AH- group). The Global Registry of Acute Coronary Events (GRACE) risk score was lower in the AH- group, but the use of guidelines-recommended treatment was comparable in all groups. At 1 year, the mortality rate was higher in the AH+ group compared with the AH- group (18.8 vs. 6.1%, P < 0.01) and similar to that in the diabetes group (18.8 vs. 16.6%, P = NS). The relation between glycaemic status and mortality remained strong [AH+ vs. AH-, OR = 3.0 (1.5, 6.0) and diabetes vs. AH-, OR = 3.6 (1.7, 6.6)] after adjustment for the GRACE risk score [OR = 2.4 (1.8, 3.1) per 10% increase] and for treatment score [OR = 0.7 (0.6, 0.8) per 10% increase].
In patients without a history of diabetes, the presence of AH indicates an increased risk of 1-year mortality, similar to that of patients with diabetes, even when the risk score and use of guidelines-recommended treatment are controlled for.