Patients with diabetes who have an acute coronary syndrome event have increased risk for death at 30 days and one year afterward compared with patients without diabetes, according to an article in the August 15 issue of the Journal of the American Medical Association.

“The presence of elevated blood glucose levels, diabetes mellitus, or both contributes to more than 3 million cardiovascular deaths worldwide each year. With the increase in obesity, insulin resistance, and the metabolic syndrome, the worldwide prevalence of diabetes is expected to double by the year 2030,” the authors wrote.

They add that more than 1.5 million adults in the U.S. were newly diagnosed with diabetes in 2005, and nearly 65 percent of individuals with diabetes die from cardiovascular disease in the U.S., establishing it as the leading cause of death among this growing segment of the population. The effect of diabetes on the risk of death following acute coronary syndrome is uncertain.

Sean M. Donahoe, MD, of Brigham and Women’s Hospital and Harvard Medical School, Boston, and colleagues evaluated the independent effect of diabetes on risk of death following a syndrome event at 30 days and 1 year using a large clinical trial database.

The study consisted of an analysis of patients with diabetes enrolled in randomized controlled trials that evaluated therapies for acute coronary syndrome. Patients with a syndrome event in 11 independent Thrombolysis in Myocardial Infarction (TIMI) Study Group clinical trials from 1997 to 2006 were pooled, including 62,036 patients (46,577 with ST-segment elevation myocardial infarction and 15,459 with unstable angina/non-STEMI), of whom 10,613 (17.1 percent) had diabetes.

The researchers found that the rate of death was significantly higher among patients with diabetes than among patients without diabetes at 30 days following either unstable angina/non-ST-segment infarction (2.1 percent vs. 1.1 percent) or ST-segment elevation infarction (8.5 percent vs. 5.4 percent). After adjusting for baseline characteristics and features and management of the coronary event, diabetes was independently associated with a nearly 80 percent increased risk of death at 30 days after angina/non-ST elevation infarction, and 40 percent increased risk of death at 30 days after St-elevation infarction.

At 1 year, diabetes remained a significant independent factor associated with all-cause death for patients presenting with unstable angina/non-ST-segment infarction (65 percent increased risk of death) or ST-elevation infarction (22 percent increased risk of death). By 1 year afterward, patients with diabetes presenting with unstable angina/non-ST-segment infarction had a risk of death that approached patients without diabetes presenting with ST-elevation infarction (7.2 percent versus 8.1 percent).

“Despite modern therapies for acute coronary syndrome (ACS), diabetes conferred a significant independent excess mortality risk at 30 days and 1 year following ACS. Current strategies are insufficient to ameliorate the adverse impact of diabetes. Given the increasing burden of cardiovascular disease attributable to diabetes worldwide, our study highlights the need for a major research effort to identify aggressive new strategies to manage unstable ischemic heart disease among this high-risk population,” the authors concluded.