Impact of arterial injury on neointimal hyperplasia after Zotarolimus-eluting stent implantation: an IVUS study

ABSTRACT

The amount of neointimal hyperplasia (NIH) correlates with the degree ofarterial injury after bare-metal stent (BMS) implantation. With first generationdrug-eluting stent (DES) this effect of arterial overstretch as assessed by balloonto-artery ratio (BAR) on NIH formation appears to be diminished; however theimpact of BAR on NIH following second generation DES remains unknown.Methods and results: From January to December 2006, 86 pts with 98 lesions(115 stents) underwent percutaneous coronary intervention (PCI) withintravascular ultrasound (IVUS) evaluation twelve months after zotarolimus-elutingstent (ZES) implantation. Arterial injury was defined as BAR, which wascategorised into two groups high BAR (>1.15, n=47) and low BAR (<1.15, n=39).The aim of this study was to investigate the impact of arterial injury on NIHfollowing implantation of ZES. Least-squares linear regression was use to assessthe association between NIH and BAR at twelve months. Overall, mean age was60 years and 33% had diabetes mellitus, there were no significant differencesregarding other baseline characteristics between groups. At baseline, meanreference vessel diameter (2.62±0.5 mm vs. 2.35±0.4 mm, p=0.006) and nominalstent diameter (3.15±0.5 mm vs. 2.85±0.3 mm, p=0.002) were smaller in the highBAR group; and at twelve-month evaluation, lumen volume (110.7±91.9 mm3 vs.154.3±91.3 mm, p=0.002), stent volume (134.0±113.8 mm vs. 174.9±98.0 mm,p=0.005) and vessel volume (249.2±207.5 mm vs. 325.0±161.8 mm, p=0.003)were higher in high BAR group as compared to the low BAR group. Regardingpercentage of NIH obstruction, there was no significant difference in low BAR vs.high BAR group (15.2±14.3% vs. 12.5±10.1%, p=0.62). Finally, arterial injury asassessed by BAR was not significantly associated with the amount of NIH (R20.0025, p=0.88).