One of the purposes of the study is a cost-effectiveness analysis. Centers participating in the study should therefore perform PCI according to their common practice with no interference in their decision-making process or technical approach to PCI because of the inclusion of the patients into a randomized study; this is aimed at obtaining an as real as possible situation of the daily practice. Being an spontaneous research, neither a fee will be provided for the enrollment of patients, nor free stents will be given.