Hyperglycemia and Acute Coronary Syndrome
The American Heart Association (AHA) released a scientific position paper in the Journal Circulation, in March, 2008 on the role of high blood sugars and Acute Coronary Syndrome (ACS). Hyperglycemia, although frequently documented in ACS patients, remains largely unappreciated as a risk factor and is undertreated in both the acute care and outpatient care settings. The researchers believe this is due largely in part to a lack of evidence-based research.
The important issue addressed in this paper is whether high blood sugars are direct mediators of adverse outcomes in ACS patients or if they are just a marker of greater disease severity. Given the marked increase in short and long term mortality associated with hyperglycemia of the ACS patient there is an urgent need for large randomized trials to determine whether treatment strategies aimed at glucose control will improve patient outcomes and to define specific glucose targets.
Until the knowledge gaps have been addressed by these randomized trials, the following set of recommendations has been set forth as a general reference:
- Glucose levels should be part of the initial laboratory evaluation in all patients with suspected or confirmed ACS.
- In patients admitted to the ICU, glucose levels should be maintained at < 180 mg/dl regardless of diabetes history. Until further data is available, approximation of fasting normoglycemia appears to be a reasonable goal which would be a glucose value of 90 – 140 mg/dl as long as hypoglycemia is avoided.
- Insulin (in the ICU administered as an IV infusion) is currently the most effective method of controlling hyperglycemia taking care to avoid hypoglycemia.
- Treatment should be instituted as soon as feasible aside from other life-saving measures, which of course, would be the first consideration.
- In patients in a non-ICU setting, the use of subcutaneous insulin should be used with the goal being to keep the glucose levels < 180 mg/dl.
- ACS patients with hyperglycemia but without prior history of diabetes should have a fasting glucose and HbA1C done and in some cases, an oral glucose tolerance test post-discharge.
- Before discharge, plans for optimal outpatient glucose control should be determined in those patients with established diabetes, newly diagnosed diabetes and in those who have demonstrated insulin resistance.
Clearly, more studies are needed. Just recently I wrote about how tight glucose control in ICU could compromise brain glucose metabolism. The evidence-based studies we need will hopefully tell us more about blood glucose goals and provide clearer targets to achieve in ICU, hospitalized and outpatient settings when it comes to a variety of conditions, not just ACS patients.
About the Author
Kathy Shattler received her Master of Science degree from Michigan State University in E. Lansing Michigan in Human Nutrition. Her twenty-two years of practice includes holding positions as a Lecturer, Chief Clinical Dietitian and Program Manager. Kathy is the Founder of Nutri-Care Consulting and is currently the Nutrition Director of www.CEU4U.COM, an online continuing education management company for Registered Dietitians and Dietetic Technicians.
