Blood glucose predicts outcomes of patients with chest pain

By Will Boggs MD

Elevated blood glucose in patients presenting to the emergency department (ED) with chest pain is independently associated with an increased risk of cardiac events in the next 30 days, researchers from Australia and New Zealand report.

"We were not totally surprised by these findings, as the effects of presentation glucose as a predictor of outcomes in cases of confirmed acute coronary syndrome (ACS) have been widely studied," Dr. Louise Cullen from Royal Brisbane and Women's Hospital in Brisbane, Australia, told Reuters Health by email.

"However, its use as a diagnostic indicator in the ED for all patients with possible ACS has not been widely studied, and indeed the incorporation of blood glucose in existing or future risk stratification tools for ACS is yet to be assessed," she said.

Using data from a prospective observational study, Dr. Cullen and colleagues found that one in five patients (336/1,708) experienced a major adverse cardiac event (MACE) within 30 days of presentation to the ED, including 98 with unstable angina and 232 with non-ST-elevation myocardial infarction (NSTEMI).

MACE occurred in 15.3% of patients with a blood glucose below 7 mmol/L (about 126 mg/dL) and in 30.9% of patients with a blood glucose above 7 mmol/L, the researchers report in the Emergency Medicine Journal, online October 24.

After controlling for baseline characteristics, other risk factors, ECG findings, and troponin results, patients with a presenting blood glucose of 7 mmol/L and above had 51% higher odds of experiencing a MACE than did patients with lower presenting blood glucose levels.

Other significant predictors of MACE included male gender, older age, hypertension, family history, dyslipidemia, ischemic ECG, and positive troponin tests.

"Further study along these lines would be of great benefit," Dr. Cullen said. "Until those studies are completed, we suggest physicians proceed with current care plans, although increased adherence to baseline blood glucose measurement and use of that measurement as a potential red flag when used alongside other known predictors may be useful."

Dr. Rajendra H. Mehta from Duke Clinical Research Institute in Durham, North Carolina, has studied the association between components of the metabolic syndrome and outcomes of patients with ACS. He told Reuters Health, "While elevated glucose, low potassium, and high WBC count have all been shown to be markers of ACS and heightened risk in patients presenting with chest pain, it is unclear as to which of these 3 is prognostically the most important marker of risk."

"If a patient comes with chest pain to ER and has negative ECG and outcomes, please not only consider baseline risk factors and cardiac biomarkers, but also elevated glucose and WBC count and low potassium as important markers of elevated risk and watch these patients closely," Dr. Mehta advised in an email.

"Studies of aggressive control of glucose in ACS patients have shown mixed results," Dr. Mehta added. "Thus, while increased glucose has been shown to be an important predictor of worse outcomes in ACS, treating this high sugar aggressively has not shown to impact outcomes."

SOURCE: http://bit.ly/1xrneA6

Emerg Med J 2014.

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