Endothelial dysfunction following drug-eluting stent implantation: A systematic review of the literature

BackgroundWhile several studies have reported endothelial dysfunction after drug-eluting stent (DES) implantation, their study methods differed and the results were varied.Methods and resultsA literature search was performed using PubMed where 14 clinical studies (537 patients) including two randomized trials were identified. All studies assessed endothelial dysfunction 3-14 months after stent implantation. In the acetylcholine (ACh) loading studies, significant vasoconstrictions were observed in proximal and distal segments after implantation of sirolimus-eluting (SES) and paclitaxel-eluting stents (PES) and a milder diameter change was observed after zotarolimus-eluting stent (ZES) implantation. Coronary diameter changes were greater in distal segments. Significant diameter change was not detected after bare metal stent (BMS) implantation. In the exercise examinations, vasoconstriction was observed in distal and proximal segments following SES and PES implantation, whereas vasodilation was observed in BMS. In the pacing examinations, vasoconstriction was observed in both SES and PES implantations in distal and proximal segments, whereas vasodilation was observed in not only BMS but ZES and biolimus-eluting stents (BES) as well.ConclusionIn the chronic phase following stent implantation, marked abnormal vasoconstriction distally in the stent was observed in SES and PES implantation but not in ZES or BES, compared with BMS. To clarify the clinical implications and possible mechanisms of these findings, longer-term evaluation with larger patients is needed.