Background As endothelial dysfunction can be responsible for myocardial ischemia even in the absence of significant coronary lesions, we aimed to assess the correlation between endothelium-dependent vasomotor function and inducible ischemia late after successful coronary angioplasty.
Methods In 30 patients without angiographic restenosis or coronary disease progression, coronary endothelial function was determined by acetylcholine infusion 6 months after elective single-vessel stenting of the left coronary artery. Acetylcholine-induced diameter changes were assessed in the proximal and distal segments of both the stented and the contralateral vessels by means of quantitative coronary angiography. A maximal workload ergometric test was also performed prior to endothelial function testing.
Results Acetylcholine induced significant vasoconstrictive responses in the distal but not in the proximal segments of both the stented (-11 ± 7% versus baseline; p < .01) and the contralateral vessels (-11 ± 6%; p < .01), which were significantly correlated (R = .48; p < .05) and were completely reverted by nitroglycerine. Inducible ischemia was the only predictive factor for distal vasoconstriction in the stented vessel (p < .01) but not in the contralateral vessel (p = .06). Patients with minor signs of ischemia at the ergometric test showed a greater vasoconstriction than those with a completely normal test (-16 ± 7% versus -7 ± 6%; p < .01).
Conclusions Exercise-induced ischemia late after successful percutaneous coronary intervention is related to distal coronary endothelial dysfunction.