The study is prospectively conducted at 4 high-volume PCI center in China with OCT expertise. Angiographic follow-up and OCT imaging with motorized pull-back at 1 mm/s are planned in all patients 12 months after implantation of the study stents. OCT endpoints are: (1) Subclinical intra-stent thrombus, defined as a mass protruding to the lumen with significant attenuation, and respectively (2) endothelial coverage, expressed as % of struts without coverage and % of stent length containing non-covered struts. The study is powered for OCT endpoints, which are likely to reach significance at the level P < 0.05 even at a follow-up drop-out rate up to 10%.