NEW YORK (Reuters Health) – A Danish study indicates that among patients undergoing percutaneous coronary intervention, the use of zotarolimus-eluting stents (ZESs) rather than sirolimus-eluting stents (SESs) is associated with more major adverse cardiac events – particularly in patients with diabetes.

“Implantation of ZESs compared to SESs is associated with a considerable increased risk of adverse events in patients with diabetes at 18-month follow-up,” report Dr. Michael Maeng, at Aarhus University Hospital, and colleagues in the American Journal of Cardiology online August 25.

They point out that the zotarolimus-eluting stent has been compared to the SES primarily in patients with non-complex lesions. However, they say they and others “have found the ZES to be inferior to the SES in patients receiving routine clinical care including those with complex lesions.”

For the current study, the team compared clinical outcomes using ZES versus SES in patients with and without diabetes. Specifically, they randomized 1162 patients to treatment with ZESs and 1170 to SESs. There were 169 and 168 patients with diabetes in the two arms, respectively.

Among the subset of patients with diabetes, the rate of major adverse cardiac events, defined as a composite of cardiac death, myocardial infarction, or target vessel revascularization, was 18.3% in the ZES arm and 4.8% in the SES arm (hazard ratio 4.05), the investigators report.

Respective rates of individual MACE components in the two arms were 4.7% vs 0.6% for MI, (HR 8.09), and 14.2% vs 3.0% for target vessel revascularization (HR 4.99).

Among non-diabetic patients, differences in MACE rates were smaller at 8.3% with ZES versus 4.5% with SES (HR 1.87), but were still statistically significant, the report indicates.

The authors suggest that “a key limitation of the ZES is its relatively high late lumen loss owing to less effective inhibition of neointima formation.”

They add, “Diabetic patients have smaller reference diameters because of exaggerated atherosclerotic disease and thus have a lower capacity to accommodate the higher late lumen loss of the ZES than nondiabetic patients.”

Dr. Maeng and colleagues estimated the numbers-needed-to-treat to be 7 for diabetic patients and 26 for nondiabetic patients in favor of SESs. “Although interaction analysis did not reach the conventional limit for significance,” they conclude, “the numbers strongly suggest an incremental benefit of the SES in diabetic patients.”

Reference:
Outcome of Sirolimus-Eluting Versus Zotarolimus-Eluting Coronary Stent Implantation in Patients With and Without Diabetes Mellitus (a SORT OUT III Substudy)
Am J Cardiol 2011