BACKGROUND: The long-term presence of the stent polymer in contact with the vessel wall has been associated to intense inflammatory response and late adverse events. However, absence of the stent polymer may compromise drug dose and drug delivery kinetics, leading to some efficacy issues. We aimed to compare, by means of serial quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS), the efficacy of the novel nonpolymeric low-dose (55 µg) VESTAsyncTM (VES) sirolimus-eluting stent, with the permanent polymer, high-dose (140 µg) CypherTM sirolimus-eluting stent (CYP). METHODS: Fifteen patients with single, de novo lesions < 14 mm, in native vessels of 2.5 mm to 3.5 mm diameter, were treated with VES and compared to a paired historical cohort of 15 patients treated with CYP. QCA and IVUS data were obtained post-procedure and at 4 and 12-month follow-up. Primary endpoints were the comparison of in-stent late luminal loss and percentage of intimal hyperplasia obstruction. RESULTS: Clinical characteristics were similar between groups. The VES group had smaller vessels (2.67 ± 0.32 mm vs. 2.98 ± 0.4 mm; P = 0.02). At 4 months, the VES group had a tendency towards a higher in-stent late luminal loss (0.30 ± 0.25 mm vs. 0.10 ± 0.3 mm; P = 0.06) but similar IVUS % of intimal hyperplasia obstruction (2.8 ± 2.2% vs. 2.2 ± 3.8%; P = 0.60). At 12-months, in-stent late luminal loss was 0.37 ± 0.24 mm (VES) vs. 0.16 ± 0.36 mm (CYP), P = 0.074, and the IVUS % of intimal hyperplasia obstruction was 4.0 ± 2.2% (VES) vs. 2.4 ± 3.9% (CYP), P = 0.17. There were no cases of binary restenosis. CONCLUSION: The VES proved safe and effective in reducing intimal hyperplasia formation up to 12 months. The absence of the polymer, as well as the lower drug dose, did not impact the efficacy of this device. Whether these changes will affect the safety profile of this novel DES has to be confirmed in a larger cohort of patients and longer follow up.
Stents; Drug-eluting stents; Sirolimus; Angiography; Ultrasonics
