ARLINGTON, VA. — Drug-eluting stents may have an advantage over bare-metal stents in major cardiac and cerebrovascular events, but the picture is less clear when it comes to diabetic patients and late thrombosis, according to data presented at a meeting sponsored by the Cardiovascular Research Institute at Washington Hospital Center.
Researchers in Argentina compared outcomes at 1, 2, 3, and 5 years' follow-up in patients with multivessel coronary artery disease (CAD) who were prospectively treated with drug-eluting stents—either the Cypher sirolimus or the Taxus paclitaxel stent in the Argentine Randomized Study: Coronary Angioplasty With Stenting Versus Coronary Bypass Surgery in Patients With Multiple Vessel Disease (ERACI) III—with similar cohorts of patients from the earlier ERACI II trial, which treated CAD patients with either bare metal stents or coronary artery bypass grafting (CABG).
“This multicenter, prospective, controlled study of patients with multivessel CAD treated either with sirolimus- or paclitaxel-eluting stents demonstrated a significant reduction of major adverse cardiac and cerebrovascular events [MACCE] and the need for repeat revascularization procedures when compared with our previous bare-metal data from ERACI II,” said principal investigator Alfredo Rodriguez, Ph.D., of Otamendi Hospital in Buenos Aires.
A total of 225 patients treated with drug-eluting stents (DES) in five centers in Buenos Aires were prospectively enrolled in the ERACI III trial during 2002–2004. Just over a fifth of patients were diabetic (22%) and 37% had type-C lesions. They were compared with 500 patients from the earlier ERACI II, of whom 225 underwent CABG and 225 were treated with bare-metal stents (BMS). Of the combined group, 17% were diabetic and 15% had type-C lesions. Of the DES patients, 48% were treated with paclitaxel-eluting stents and 52% with sirolimus-eluting stents.
“DES versus bare metal and DES versus CABG are associated with lower MACCE at follow-up,” said Dr. Rodriguez. The incidences of MACCE at 1 year were 22%, 20%, and 12% for patients with BMS, CABG, and DES, respectively, on the basis of a univariate analysis. There was no significant difference in the MACCE rate between the two drug-eluting stents.
Drug-eluting stents showed less benefit for diabetic patients in terms of MACCE at 1 year follow-up. In DES patients in ERACI III, there was a nonsignificant trend toward higher mortality in the 47 diabetic patients than in the 178 nondiabetic patients (23% and 9%, respectively). Diabetic patients had a higher incidence of acute myocardial infarction (9%) and repeat percutaneous coronary intervention or CABG (17%), compared with nondiabetic patients (1% and 7%, respectively). Researchers also looked at the incidence of in-stent thrombosis over time. Three BMS patients had in-stent thrombosis, compared with eight DES patients. The times at which thromboses were detected were even more telling: Three patients with BMS and none with DES were identified with in-stent thrombosis while in the hospital.
After hospital discharge and out to 3 years, no BMS patients had in-stent thrombosis. Three DES patients had stent thrombosis after discharge, but still in the first 30 days. Another three in this group developed stent thrombosis in the first year, and one other patient developed stent thrombosis by the 3-year follow-up. Three of the DES patients with stent thrombosis had MIs and three died. Dr. Rodriguez reported no conflicts of interest.