Diabetes control among patients presenting with acute myocardial infarction in a Canadian tertiary health care setting

Background: The use of an insulin infusion following myocardial infarction, and its consequent lowering of glucose, significantly improves mortality. Objective: To explore whether this knowledge was being applied in clinical practice. Methods: The authors conducted a chart audit of all subjects with an acute myocardial infarction admitted to the coronary care unit of a tertiary health care centre in Nova Scotia between January 1, 2000 and December 31, 2000. Information was obtained from a computerized database as well as individual chart review. Treatment of patients with and without diabetes was specifically compared. Results: There were 447 total admissions. One hundred and twenty-eight had diabetes mellitus and the majority of these (93%) had type 2 diabetes. Most patients (54%) sustained a non-Q wave infarction and 77% had either thrombolytic therapy or cardiac catheterization. Mean glucose on admission and discharge was 11.32 mmol/L and 9.86 mmol/L, respectively. Diabetes was managed conservatively among 98%, and only 2% received insulin infusion therapy. Only 16.3% of diabetic patients had their glycated hemoglobin A1c checked (mean value 9.12%). In-hospital mortality was 21% among patients with diabetes and 10.4% among those without. Conclusions: The present study highlights the poor outcome of patients with diabetes presenting with acute myocardial infarction. Despite clinical trial evidence suggesting that use of insulin infusion would confer significant benefit in this population, it was markedly underused even in a setting where other evidence-based therapies were well prescribed. These findings raise questions about the need for national clinical practice guidelines incorporating the use of insulin infusion in standard care.