Assessing the temporal course of neointimal hyperplasia formation after different generations of drug-eluting stents

ABSTRACT

Objectives This study sought to assess the temporal course of neointimal hyperplasia (NIH) formationfollowing implantation of 2 different generations of drug-eluting stents (DES).Background The amount of NIH following DES implantation correlates with the potency of the antiproliferativedrug, its kinetic release, as well as some individual characteristics, as the presence ofdiabetes mellitus (DM). Recently, some publications have suggested a continuous growth of NIH followingDES, which in some cases, might result in late “catch-up.”Methods Twenty-five patients with single, de novo lesions were treated with sirolimus-elutingstents (SES) (n 12) and biolimus-eluting stents (BES) (n 13) and underwent intravascular ultrasoundevaluation immediately after the procedure and at 9-month and 5-year follow-ups. The primaryendpoint was the comparison of the percentage of NIH obstruction between mid- and longtermfollow-up.Results Mean age was 59 years and 28% of patients had DM. Overall, the percentage of NIH obstructionsignificantly increased from 9 months to 5 years (1.3% at first follow-up vs. 4.8% at secondfollow-up, p 0.002). There was no significant difference in the variation of vessel volume (Ä 0.70 mm3/mm BES vs. Ä 0.18 mm3/mm SES, p 0.56), lumen volume (Ä 0.40 mm3/mm BESvs. Ä 0.05 mm3/mm SES, p 0.71), and percentage of NIH obstruction (Ä 3.0% BES vs. Ä 3.8% SES, p 0.55) among DES. However, diabetic patients had a marked NIH increase along theyears (NIH volume at second follow-up 10.15 mm3 DM vs. 5.11 mm3 non-DM, p 0.028).Conclusions The present serial intravascular ultrasound assessment supports the occurrence of continuousNIH growth following different generations of DES. These findings seem to be particularlymore pronounced among patients with DM.