Balloon/Artery Ratio and Neointimal Hyperplasia Volume Obstruction After Zotarolimus-Eluting Stent Implantation

Background:  Intimal hyperplasia volume is correlated to arterial injury after bare-metal stenting. However, little is known about the impact of arterial injury on the inflammatory/ proliferative response with drug-eluting stents. We investigated the impact of arterial injury, evaluated by the balloon/artery ratio, on neointimal hyperplasia volume obstruction, evaluated by intravascular ultrasound, 12 months after zotarolimus-eluting stent implantation.

Methods:  Balloon/ artery ratio was defined as the ratio of the maximum balloon diameter, using the maximal implantation or post-dilatation pressure, and the reference diameter of the vessel obtained before the procedure. Patients were divided into two groups: high balloon/artery ratio (≥ 1.15) and low balloon/artery ratio (< 1.15).

Results:  A total of 86 patients were included in the low balloon/artery ratio group (n = 47/48 lesions) or high balloon/artery ratio (n = 39/48 lesions). The clinical, angiographic and procedurerelated characteristics were not different between groups, except for the vessel reference diameter (2.73 ± 0.45 mm vs. 2.97 ± 0.40 mm; p = 0.01). At 12 months, similar in-stent late loss was observed (0.59 ± 0.32 mm vs. 0.62 ± 0.42 mm; p = 0.92), as well as binary restenosis (4.2% in both cohorts; p > 0.99). Instent neointimal hyperplasia volume obstruction (15.2 ± 14.3% vs. 12.5 ± 10.1%; p = 0.62) showed no difference between groups. No correlation was observed between balloon/artery ratio and neointimal hyperplasia obstruction volume at 12 months (R2 = 0.0025; p = 0.88).

Conclusions:  In the present study arterial injury was not correlated with the amount of intimal hyperplasia after zotarolimus-eluting stent implantation.

Coronary restenosis; Percutaneous coronary intervention; Drug-eluting stents