Quality assurance: At all investigational sites the investigators are trained to the registry protocol, case report forms and registry procedures prior to enrolling subjects. The assigned monitoring investigator at the main site, will assure regular site monitoring and auditing at all investigational sites. Source data will be verified by comparing the data to medical records and case report forms in the form of a random sample. To avoid or minimize bias, an independent clinical events committee at the main investigational site, consisting of independent physicians, assesses all primary endpoint clinical events. Intermediate evaluation will take place one year after enrollment of the last patient and consists of a verification of recorded data, assessment of accuracy of patient follow-up and primary endpoint analysis.