Admission blood glucose level as a potential indicator for short-term mortality and morbidity after myocardial infarction

Abstract

AIMS: Hyperglycemia is common among patients with acute myocardial infarction (AMI) and is associated with high risk of mortality and morbidity. However, the relationship between admission plasma glucose (APG) levels and mortality in diabetic and nondiabetic patients with AMI needs further investigation. The aim of this study was to investigate the relationship between APG level and short-term mortality and morbidity after AMI. MATERIALS AND METHODS: This is a prospective study of 79 consecutive patients with AMI followed up for 90 days. Medical history, as well as demographic and clinical baseline characteristics, of the patients was obtained from Al-Watni Governmental Hospital medical records. The patients were divided into four groups based on APG levels. Patients’ health status was followed up by phone call interviews with the patients and their families. Follow-up data were further confirmed using patients’ medical records at the hospital. The phone interviews investigated all causes of death or congestive heart failure (CHF) or reinfarction. RESULTS: The mean age of patients was 61.9 ± 12.3 years. At the time of hospital admission, the median PG level was 162 mg/dl. During the 3-month follow-up, overall mortality was 20.3% and was increased to 56.3% in patients with glucose levels >200 mg/dl. Mortality Previous studies have indicated that hyperglycemia is common in patients with acute myocardial infarction (AMI) and is associated with increased risk of mortality. [1-4] However, many aspects of the relationship between admission plasma glucose (APG) levels and mortality in AMI patients need to be further investigated. For example, the full range of APG levels and current diabetic state need to be considered in the investigation. Studies which did investigate these aspects were inconclusive. [5-7] For example, in a study of 846 patients with AMI and follow-up during a median of 50 months, APG level after AMI was found to be an independent predictor of long-term mortality and that subjects with APG levels of 200 mg/dl or more after AMI were found to have mortality rates comparable to those of subjects with established diabetes. [7] In another study of 141,680 elderly patients hospitalized with AMI, APG level was analyzed for its association with mortality in patients with and without recognized diabetes. In that study, the authors found that hyperglycemia was common, rarely treated and was associated with increased mortality risk in elderly patients with AMI, particularly those without recognized diabetes. [8] In a third study carried out in Japan, patients hospitalized for newly diagnosed AMI was comparable (21.9% vs. 19.1%; P > 0.05) between diabetic and nondiabetic patients. Nonfatal adverse outcomes in the form of combined CHF and re-infarction were highest in group IV and lowest in group I. CONCLUSION: Our study demonstrates that high APG level is common in patients with AMI and is associated with high risk of mortality and morbidity among patients with or without diabetes mellitus. In fact, our study showed that nondiabetic patients with high APG have higher risk of mortality than patients with a known history of diabetes mellitus.