Randomized comparative trial of a thin-strut bare metal cobalt-chromium stent versus a sirolimus-eluting stent for coronary revascularization

Abstract

Objectives: To see whether use of a sirolimus-eluting stent (SES) is superior to a third-generation thin-strut, cobalt-chromium stent (CCS) in terms of in-segment late loss at 9 months in patients with symptomatic coronary artery disease.

Background: Stent-strut thickness has been shown to be strictly related with risk of in-stent restenosis, but available demonstrations of the angiographic efficacy of SES have been based on comparisons with thick-strut bare metal control stents.

Methods: The primary outcome measure of this single-center, single-blind randomized comparative trial was 9-month in-segment late loss. Eligibility criteria were symptomatic coronary artery disease and target vessel diameter appropriate for implantation a 3-mm stent. Based on a power calculation, 104 patients were randomly assigned to receive a SES (Cypher) or a CCS (Vision).

Results: In-segment late loss was significantly lower in the SES group (0.18 +/- 0.40 mm vs 0.58 +/- 0.51 mm, P < 0.001). Regarding subsidiary outcome measures, in-segment restenosis (at 9 months) was recorded in 10% (5/50) patients treated with SES and 23% (11/48) receiving CCS (P = 0.14). No clinical difference between the two groups was apparent at 12 months. Freedom from target vessel failure at 12 months was 72% for SES patients and 68% for CCS patients (P = 0.65).

Conclusions: In patients with de-novo coronary lesions at medium risk of restenosis the anti-proliferative effect of SES is greater than that of a thin-strut CCS. Nevertheless, the angiographic results of the CCS were rather good. It remains to be seen whether the angiographic superiority of SES can translate into clinical superiority.