Serial randomized comparison of strut coverage of everolimus- and first-generation sirolimus-eluting stents

There has not been sufficient data to evaluate the serial vascular healing pattern after everolimus-eluting stent (EES) implantation. Using optical coherence tomography, we compared serial changes in strut coverage of the EES and the first-generation sirolimus-eluting stent (SES).

Sixty patients were randomly assigned to receive either EES (n = 30) or first-generation SES (n = 30) for coronary artery disease. Serial optical coherence tomography evaluation immediately after the procedure, and 3- and 12-month follow-ups were performed in 50 patients with 54 stents (25 patients with 28 EES vs. 25 patients with 26 SES). The percentage of uncovered struts was defined as the ratio of uncovered struts to total struts. The primary end point was the percentage of uncovered struts at 12-month follow-up. The secondary primary end point was the percentage of uncovered struts at the 3-month follow-up and the comparative percentage change (Δ) of uncovered struts at 3- and 12-month follow-ups of EES vs SES.

The percentage of uncovered struts was significantly lower in the EES group compared with the SES group (median value, 6.9%; interquartile range [IQR], 3.9-10.6% vs. 11.1%; IQR, 5.5-29.4%, respectively) at the 3-month follow-up (P = 0.03), and at the 12-month follow-up (median value, 1.3%; IQR, 0.3-3.5% vs. 3.6%; IQR, 1.0-9.4%; P = 0.02). The percentage Δ of uncovered struts from the 3- to the 12-month follow-up was similar (-7.0 ± 6.9% in EES vs. -10.5 ± 13.6% in SES; P = 0.24).

The EES group showed more favourable stent strut coverage than the first-generation SES group at the early and late periods after stent implantation. These findings suggest that EES have a more beneficial effect for vascular healing.