Research Activities, October 2013
Older diabetic patients have a greater risk than nondiabetic patients for long-term adverse events after coronary stenting
One-third of older patients who receive percutaneous coronary intervention (PCI) have diabetes, and these patients are at increased risk for long-term adverse events, including heart attack and death, according to a new study. During PCI, a catheter is threaded up through an artery into the heart where the blockage is removed in the coronary artery. Then a stent is placed to keep the artery open.
Researchers analyzed data on 405,679 patients 65 years of age and older who underwent a PCI. A third of these patients had diabetes, with 9.8 percent receiving insulin. These data were then linked with Medicare inpatient claims data on four major clinical endpoints: death, heart attack, the need for additional revascularization procedures, and bleeding requiring hospitalization. The average followup was 20 months.
Compared to nondiabetic patients, those with diabetes had more coexisting conditions at baseline. The majority of patients received a PCI using a drug-eluting stent, which slowly releases a blood thinner to prevent future clots in the coronary artery. Others received a bare-metal stent.
At 3 years, mortality was more than double for older patients with insulin-treated diabetes compared to older nondiabetic patients (23.7 vs. 11.1 percent). The mortality rate was 14.2 percent for diabetic patients not taking insulin. Both types of diabetic patients had a significantly increased risk of having a heart attack compared to nondiabetics. In addition, diabetic patients had a greater risk for needing additional revascularization procedures or being hospitalized for bleeding. However, receiving a drug-eluting stent was associated with a reduction in death for both types of diabetic patients and decreased risk of heart attack for diabetic patients taking insulin. The study was supported in part by AHRQ (Contract No. 290-05-0032).
See "Long-term outcomes of older diabetic patients after percutaneous coronary stenting in the United States," by William B. Hillegass, M.D., M.P.H., Manesh R. Patel, M.D., Lloyd W. Klein, M.D., and others in the December 4, 2012, Journal of the American College of Cardiology 60(22), pp. 2280-2290.