Implications of hyperglycaemia and ethnicity in patients with acute coronary syndromes in New Zealand.

BACKGROUND

Admission blood glucose (ABG) is an independent predictor of death in patients with acute ST elevation myocardial infarction (STEMI). In New Zealand, mortality following myocardial infarction is disproportionally higher in Maori. Little information, however, exists concerning the predictive value of ABG in non-ST elevation acute coronary syndromes (NSTEACS) events or indeed if similar ethnic differences exist in outcome in this patient population.

AIM

To assess the predictive value of ABG and ethnicity in individuals admitted with acute coronary syndromes (ACS) on mortality.

METHODS

A retrospective analysis of hospital discharge diagnosis of all ACS between 1 January 1999 and 31 December 2002 at Waikato hospital, Hamilton, New Zealand. The primary outcome was all-cause mortality.

RESULTS

There were 4408 episodes of ACS with 1091 (25%) due to STEMI. There were 806 (18%) deaths. The presence of diabetes mellitus (DM) or an elevated ABG, in the absence of a history of DM, was associated with poor patient outcome. Early mortality is seen in individuals presenting with STEMI. People in the highest glucose category were older, more likely to be Maori, had a higher percentage of people with diabetes and remained in hospital longer, regardless of ACS type, than those in the lowest glucose category. Diabetes was more common in Maori (33%) than in Europeans (17.5%); p < 0.001. Significant risk factors for mortality were age, gender, diabetes, ethnicity, glucose and STEMI. For each mmol/l increase in glucose there is a 4.3% increase risk of dying. Adjusting for age and gender, Maori have a much higher mortality than Europeans (RR 2.12; p < 0.00001) regardless of ACS type (STEMI or NSTEACS).

CONCLUSIONS

Our study confirms the higher mortality following ACS, of Maori compared to New Zealanders of European origin. A raised ABG is a marker of this increased risk in all patients with ACS.