Background: Stenting has proved beneficial for treating threatened closure and reducing restenosis after balloon angioplasty. However, the implantation of a coronary metallic prosthesis has been related to impaired vasomotion distal to the stent as assessed by acetylcholine infusion. Thus, the purpose of the present study was to determine the vasomotion of stented coronary arteries and to assess its influence on the vasomotion of adjacent vessel segments during bicycle exercise.
Methods and results: Biplane quantitative coronary angiography was performed at rest and during bicycle exercise in 26 patients with coronary artery disease. Twelve patients had single vessel disease with stable angina pectoris (controls; group 1). Fourteen patients underwent coronary stenting for therapeutic reasons and were studied 10+/-3 months after the intervention (group 2). Minimal luminal area, stent area, and proximal and distal vessel areas were determined. In controls (group 1), vasoconstriction of the stenotic artery (- 29+/-4%; P<0.001) was observed during exercise, whereas the normal segment showed vasodilation (15+/-4%; P<0.05). In group 2, vasomotion of the stented segment was eliminated (0+/-1%), whereas the proximal and distal segments showed exercise-induced vasodilation (8+/-2% and 11+/-3%, respectively; P<0.005), which was not different from control segments (10+/-2%). Sublingual nitroglycerin was associated with maximal vasodilation of the proximal and distal vessel segments (30+/-8% and 38+/-13%, respectively; P<0.005).
Conclusions: In contrast to the vasoconstriction of vessels in control patients, normal vasodilation of proximal and distal segments occurred during the physiological stress of exercise in patients with coronary stent placement. As expected, vasomotion was abolished in the stented region.