Drug-eluting stents show increased safety in diabetics

Drug-eluting stents (DES) were associated with decreased rates of death, myocardial infarction (MI), and revascularization at 3 years of follow up in diabetic patients compared to bare-metal stents (BMS), according to results of a large observational study. “Our primary concern was to look at safety,” says Laura Mauri, MD (pictured) Brigham and Women’s Hospital and Harvard Medical School, Boston. “Considering the safety concerns surrounding DES recently, it was to our surprise that we found a significant difference in the opposite direction.

“Our best estimate now is that one third of the population will present for coronary stenting and diabetics have a higher prevalence of ischemic heart disease than the general population,” Dr. Mauri explains. Furthermore, PCI is associated with certain limitations in diabetics because these patients have a higher risk of restenosis, MI, and cardiac mortality after the procedure.

Dr. Mauri and colleagues reviewed 21,045 PCI cases performed in non-federal Massachusetts hospitals between April 1, 2003 and September 30, 2004. She notes that 28.5 percent of the PCI patients were diabetic; 33 percent of these required insulin. Researchers then identified 5,423 evaluable diabetic patients and excluded 372 who had received both stent types. Of the remaining PCI patients, 66 percent (n=3,341) received DES and 34 percent (n=1,710) received BMS. Among DES patients, 75 percent received sirolimus stents and 25 percent received paclitaxel versions.

To help validate the observational study results, researchers applied propensity score matching and performed logistic regression to predict DES treatment by 67 patient, procedural, and hospital variables and then analyzed outcomes in 2,952 matched DES and BMS patients with 1,476 in each group. The primary outcome measures were matched risk differences for mortality, MI, and revascularization rates after 3 years.

The most significant difference seen was a 5.4 percent reduction in required target vessel revascularization among DES patients (n=271) compared with BMS patients (n=350) during the 3-year follow up (P<0.001). There was also a 3 percent reduction in MI, which occurred in 204 DES patients and 249 BMS patients (P=0.02), and a 3.2 percent reduction in mortality with 258 and 305 patients dying during follow up (P=0.02).

The results show preserved efficacy of DES in diabetic patients, with no increased hazard of death, MI, or revascularization rates. Longer-term follow-up is needed to determine if this safety profile is maintained in this higher-risk population, Dr. Mauri says.