Local vascular dysfunction after coronary paclitaxel-eluting stent implantation

Background: Paclitaxel-eluting stents (PES) have been shown to reduce the rate of restenosis and the need for repeated revascularization procedures compared with bare metal stents. However, long-term effects of paclitaxel on vascular function are unknown. The purpose of the present study was to assess coronary vasomotor response to exercise after paclitaxel-eluting stent implantation. Methods: Coronary vasomotion was evaluated by biplane quantitative coronary angiography at rest and during supine bicycle exercise in 27 patients with coronary artery disease. Twelve patients were treated with a bare metal stent ( controls), and fifteen patients with a paclitaxel-eluting stent. All patients were restudied 6 +/- 2 (range 2-12) months after stent implantation. Minimal luminal diameter, stent diameter, proximal, distal and a reference vessel diameter were determined. Results: Reference vessels showed exercise-induced vasodilation in both groups (+20 +/- 5% controls; +26 +/- 3% PES group). Vasomotion within the stented vessel segments was abolished. In the controls, the adjacent segments proximal and distal to the stent showed exercise-induced vasodilation (+17 +/- 3% and + 24 +/- 4%). In contrast, there was exercise-induced vasoconstriction of the proximal and distal vessel segments adjacent to the paclitaxel-eluting stent (-13 +/- 6% and -18 +/- 4%; p < 0.005). After sublingual nitroglycerin, the proximal and distal vessel segments dilated in both groups. Exercise-induced vasoconstriction adjacent to paclitaxel-eluting stent correlated inversely with the time interval after stent implantation. Conclusions: Paclitaxel-eluting stent implantation is associated with exercise-induced vasoconstriction in the peristent region suggesting endothelial dysfunction as the underlying mechanism. Improvement of vascular function occurs over time, indicating delayed vascular healing. (c) 2007 Published by Elsevier Ireland Ltd.