Summary of the study design It is hypothesized that VRT will result in augmented endothelium dependent coronary vasodilation and maximal myocardial perfusion as compared with conventional stenting of a coronary lesion. Within one year sixty patients (age 18-65) with documented single vessel CAD (type A or B1 lesion) accepted for PCI based on clinical grounds and according to current international guidelines, will be asked to participate in this trial. Patients will be randomized to implantation of a drug-eluted stent (Xience Prime) or BRS (Absorb). The patients will be blinded to the nature of the implanted device. H2 15O PET will be performed one month (reference scan), one year, and three years after the PCI procedure (resolution of BRS is generally complete within a three year period). The PET protocol will consist of three MBF measurements: resting MBF, during endothelial dependent vasodilation provoked by coldpressor-testing (CPT), and during (endothelial dependent and independent) maximal vasodilation by infusion of adenosine intravenously. After three years a control invasive coronary angiogram will document any potential obstructive coronary lesions that may affect the MBF measurements.