Abstract 4927: One-Year Results of the Hydroxyapatite Non-Polymer-Based Sirolimus-Eluting Stent for the Treatment of Single De Novo Coronary Lesions - A First-in-Human Analysis of a Third Generation Drug-Eluting Stent (DES) System
Background: Recent concerns regarding DES long-term safety have been raised. Synthetic polymers have been associated with intensive inflammatory response and exacerbated positive vessel remodeling. Importantly, the association between exacerbated vessel enlargement and very late DES thrombosis has been recently demonstrated. Newly developed, the VESTASync™ Eluting Stent (VES) combines a stainless steel platform with a nanothin-microporous hydroxyapatite surface coating impregnated with a polymer-free Sirolimus formulation (55μm) that in vitro elutes drug for 30 days. Hydroxyapatite has excellent biocompatibility and occurs naturally in the body. We sought to investigate the safety, performance and efficacy of this third generation polymer-free DES.
Methods: In May 2007, 15 patients with single de novo lesion located in native coronary arteries with 3.0 –3.5mm diameter and ≤14mm in length were consecutively enrolled. Primary endpoints were 30 days MACE (safety), and in-stent late lumen loss at 4 and 9 months (efficacy). QCA and IVUS analysis were performed at independent core labs.
Results: Baseline characteristics included mean age of 63 years and 33% diabetics. LAD was the prevalent target vessel (47%). Reference diameter was 2.67 ± 0.32mm, lesion length was 9.98 ± 1.98 mm. VES was successfully implanted in all cases. There were no procedure and in-hospital complications. Lifelong aspirin and no more than 5 months clopidogrel were prescribed to all patients. At 4-month follow-up in-stent late loss (QCA) and % of volume obstruction (IVUS) were 0.30 ± 0.25 mm and 2.6 ± 2.2%, respectively. At 9-months, invasive follow-up showed an in-stent lumen loss of 0.37 ± 0.24mm and % of volume obstruction of 3.8 ± 2.3%. Importantly, vascular positive remodeling and late incomplete stent apposition were not observed in this cohort. There were no MACE / stent thrombosis cases up to one-year clinical follow-up.
Conclusions: The novel MIV (Sirolimus)-eluting stent was effective in reducing lumen loss and NIH formation at four-month follow-up; These enthusiastic initial results were sustained at nine-months, with no evidence of late “catch up” by QCA and IVUS evaluation. Long-term data in more complex groups of patients is necessary to confirm its safety profile.