REWARDS Registry Examines Stent Thrombosis
Review of 2,769 stent implantations shows both sirolimus- and paclitaxel-eluting stents are safe, with more thromboses in cypher patients.
In a registry review presented yesterday by Ron Waksman, MD, the Cypher stent (Cordis/Johnson & Johnson) showed a two to three times greater risk of thrombosis than the Taxus stent (Boston Scientific) among 2,769 patients implanted at the Washington Hospital Center.
The one-year incidence of stent thrombosis in patients receiving Cypher was 1.9% compared to 0.8% in patients receiving Taxus (P = .034).
In the registry, 1,925 patients received the Cypher stent and 844
patients received the Taxus stent.
Implantation of both stents was successful in more than 98% of cases. The incidence of repeat target lesion revascularization (TLR) in-hospital was 3.2% in the Cypher cohort compared with 1.8% in the Taxus cohort (P = .039). There were no other significant differences in in-hospital complications. Major adverse cardiac events, target vessel revascularization and TLR were comparable at one month, six months and 12 months.
Independent predictors of major adverse cardiac events
included diabetes, history of chronic renal failure, NYHA Class III/IV congestive heart failure, cardiogenic shock, saphenous vein graft lesion and previous myocardial infarction (MI).
Antiplatelet therapy
Clopidogrel (Plavix, Sanofi-Avartis) was administered to all patients with the Cypher stent for at least three months and to patients receiving the Taxus stent for at least six months. Investigators recommended 12 months of clopidogrel treatment for all patients.
Clopidogrel compliance at six months was 83.5% in the Cypher group vs. 90.6% in the Taxus group (P = .043). At the time of stent thrombosis, however, clopidogrel compliance was not significantly different between the two groups.
Complex subgroups
In subgroup analyses of complex patients – including those with ostial lesions, in-stent restenosis, non-native coronary artery lesions, lesions longer than 33 mm, type C lesions, chronic total occlusions, two or more drug-eluting stents, acute MI, type 1 diabetes mellitus or prior CABG – there was no difference in performance between the Cypher and Taxus stents in terms of major adverse cardiac events. In the complex patients, there was a greater risk of stent thrombosis for patients receiving the Cypher stent.
Drawing conclusions
The use of Cypher and Taxus stents in unrestricted, contemporary practice had comparable outcomes in terms of low rates of revascularization and clinical events, according to Waksman.
He noted that the overall stent thrombosis incidence of 1.6% remained a serious concern for clinicians employing drug-eluting stents, especially in high-risk subsets of patients, specifically complex patients and lesions and insulin-dependent diabetic patients.