Predictive value of plasma glucose level on admission for short and long term mortality in patients with ST-elevation myocardial infarction treated with primary percutaneous coronary intervention

Abstract

Published reports describe a strong association between plasma glucose levels on admission and mortality in patients who undergo primary percutaneous coronary intervention for ST-segment elevation myocardial infarction. The aim of this study was to assess the predictive value of admission glucose levels for early and late mortality. From 2005 to 2007, 1,646 patients underwent primary percutaneous coronary intervention for ST-segment elevation myocardial infarction and were stratified according to admission plasma glucose level in category 1 (<7.8 mmol/L; n = 747), category 2 (7.8 to 11.0 mmol/L; n = 620), or category 3 (>11 mmol/L; n = 279). Event rates were estimated using the Kaplan-Meier method. A landmark survival analysis to 3-year follow-up was performed, with a landmark set at 30 days. Time-extended Cox regression was used to assess the predictive value of admission glucose levels. Furthermore, a stratified analysis was performed for known diabetes mellitus status at admission. Thirty-day mortality was 2.4% in category 1, 6% in category 2, and 22% in category 3 (p <0.01). Three-year mortality in 30-day survivors was 5.9% in category 1, 8.2% in category 2, and 7.1% in category 3 (p = 0.27). Glucose level on admission was a strong predictor of 30-day mortality: for every 1 mmol/L increase, the hazard increased by 14% (hazard ratio 1.14, 95% confidence interval 1.09 to 1.19, p <0.01) in patients without diabetes, by 12% (hazard ratio 1.12, 95% confidence interval 1.05 to 1.19, p <0.01) in those with diabetes, and by 13% (hazard ratio 1.13, 95% confidence interval 1.09 to 1.17, p <0.01) in the total cohort. After 30 days, glucose level at admission lost its predictive value. In conclusion, in patients with and those without diabetes, glucose level at admission is an independent predictor of early but not late mortality.