The long-term effect of coronary stenting on epicardial and microvascular endothelial function

Background: Coronary stents, drug-eluting stents in particular, have been linked to coronary epicardial endothelial dysfunction after implantation. However, less is known about their impact on coronary microvascular function and their long-term effects on the vasculature. Methods and Results: We evaluated 71 patients (mean age, 53.0±10.1 years) with chest pain and angiographically nonsignificant coronary artery disease 17.1±17.1 months after left anterior descending coronary artery stenting. Seventy-one age- and sex-matched patients (mean age, 53.0±10.3 years) with chest pain but no prior coronary intervention served as controls. Coronary blood flow in response to the endothelium-dependent vasodilator acetylcholine as well as the microvascular (endothelium-independent) coronary flow reserve in response to intracoronary adenosine were evaluated. Quantitative coronary angiography was used to study epicardial diameter changes to acetylcholine. Microcirculatory function was not significantly different between the stenting and control groups (median [interquartile range] coronary flow reserve, 2.9 [2.5-3.4] versus 3.0 [2.4-3.4] mL/min, P=0.24; change of coronary blood flow, 34.9% [?34.4% to 90.0%] versus 54.7% [?5.6% to 104.6%], P=0.18). Both groups exhibited epicardial endothelial dysfunction (?23.0% [-47.4% to ?7.6%] versus ?20.0% [-40.0% to 0.0%], P=0.4). Results did not differ between patients with drug-eluting stents (n=46) and patients with bare-metal stents (n=24). Conclusions: This study demonstrates that in patients with coronary arteries in which a stent has been placed, coronary microcirculatory and epicardial vascular function are not significantly different from that of an age- and sex-matched population with similar symptoms but nonsignificant coronary artery disease.