BACKGROUND: Radial expansion and vessel wall scaffolding properties of stainless steel stents have improved the outcomes of coronary balloon angioplasty. Thinner struts and new platform designs are characteristic of more contemporaneous stents, but it is not clear whether these changes may result in devices with less radial strength, susceptible to elastic recoil, especially in the very late follow-up. This study was aimed at assessing late stent recoil in two generations of drug-eluting stents (DES) using serial intravascular ultrasound (IVUS) analysis. METHODS: Twenty-five patients with single de novo coronary lesions, treated with DES (12 CypherTM and 13 BioMatrixTM), were included and serial IVUS analysis was performed after stent implantation and at 4-6-months and 4-5 years of follow-up. Stent volume index was compared between the procedure and the mid and long-term follow-ups. Stent recoil was defined as a decrease > 10% of the stent volume index. RESULTS: Most of the patients were male (52%), with mean age of 58.8 ± 7.6 years, and 28% were diabetic. Stent volume index, the primary objective of this study, was 7.7 ± 1.5 mm³/mm post-procedure, 7.7 ± 2.1 mm³/mm at 4-6 months and 7.8 ± 1.6 mm³/mm at 4-5 years, with a delta of -0.02 ± 1.6 mm³/mm (P = 0.97). The long-term delta stent volume index was 0.13 ± 1.8 mm³/mm (1.7%) for the CypherTM stent and -0.05 ± 1.3 mm³/mm (-0.6%) for the BioMatrixTM stent (P = 0.78). CONCLUSIONS: Serial IVUS analysis showed that stainless steel DES of different generations did not show evidence of long-term elastic recoil.
Angioplasty; Drug-eluting stents; Ultrasonics
