Noninvasive Evaluation of Coronary Endothelial Function following Sirolimus-Eluting Stent Implantation by Using Positron Emission Tomography

Objective: Several invasive studies have reported delayed reendothelialization and endothelial dysfunction following sirolimus-eluting stent (SES) implantation. We evaluated the changes in coronary endothelial function following SES implantation by using a noninvasive method that involved positron emission tomography and cold pressor testing (CPT). Methods: The study was conducted on 14 lesions on which percutaneous coronary intervention (PCI) was successively performed. The lesions were classified into 2 groups depending on the PCI performed: the conventional PCI group, in which 7 conventional PCIs (plain old balloon angioplasty or bare-metal stents) were performed, and the SES group, in which 7 SESs were implanted. Coronary endothelial function was defined as the percent increase in the myocardial blood flow (MBF) during CPT. Results: The resting MBF in the segments distal to the PCI sites did not differ between the conventional PCI and SES groups; however, the MBF significantly decreased in the SES group during CPT. Conclusions: These data suggest that SES implantation induces coronary endothelial dysfunction in the segments distal to the PCI sites.