Short-Term Sulfonylurea Use Appears Safe for ACS Patients

A study finds that use of sulfonylureas in the period leading up to an acute coronary syndrome is not associated with increased risk of death or heart failure.

Diabetes and coronary disease are common comorbidities, but the clinical community continues to debate the best management strategy for patients with both conditions. Diabetes is associated with an increased risk of death or heart failure within 30 days of an acute coronary syndrome (ACS) event. Several observational studies have suggested that diabetes patients treated with sulfonylureas (chlorpropamide, glimepiride, glipizide, glyburide, tolazamide, and tolbutamide) may be at elevated risk of cardiovascular events. The proposed mechanism is the adenosine triphosphate (ATP)-sensitive potassium (K_ATP) channel. These channels, which are widespread in cardiac tissue, are cardioprotective when they open during ischemia. Sulfonylureas inhibit these channels and close them.

Researchers from the University of Edmonton conducted a study to determine whether use of sulfonylureas at the time of an ACS leads to increased risk of death or heart failure. Drawing on administrative databases, they examined a cohort of adult patients who experienced an ACS between April 2002 and October 2006. They compared patients who had any exposure to K_ATP channel inhibitors in the 100 days before their ACS event to patients without exposure to K_ATP channel inhibitors. Their results were published online on May 13, 2013, in Diabetes, Obesity and Metabolism.

From the 21,023 patients hospitalized with an ACS diagnosis, the researchers identified 5761 patients who also had diabetes. These patients tended to be older, were more likely to be female, and were more likely to have atherosclerotic comorbidities. They also had more complicated medical histories, including a history of prior ACS, and took more medication than others.

The results indicated that diabetes was a risk factor for both mortality and heart failure. In addition, the prognosis for diabetes patients was identical regardless of whether the patient presented with STEMI (ST-elevation myocardial infarction) or NSTEMI. However, there was no indication of an increased risk for death or heart failure within 30 days of ACS in patients who were taking sulfonylureas.

The researchers concluded that K_ATP channel inhibitors may hypothetically affect ischemic preconditioning, but their clinical impact appears to be negligible. They noted that the actual mechanism that places diabetes patients who chronically use sulfonylureas at increased risk of cardiovascular hazards needs to be identified. For the time being and in keeping with current practice guidelines, however, clinicians can continue to employ sulfonylureas as needed for short-term blood sugar management in ACS patients.

Ms. Wick is a visiting professor at the University of Connecticut School of Pharmacy and a freelance writer from Virginia.