Storage, analysis and auditing of data will be accomplished by an independent Central Core Laboratory. Auditing of the dataset will be performed every six months by checking the data of a minimum of 40% of the patients. Data without any patient identification code will be submitted to the Principal Investigator and E-AVR Steering Committee for further data checking and merging. Incomplete or contradictory data with patient identification code will be sent from Central Core Statistical Lab to the E-AVR Steering Committee local member for further data checking, review, correction and merging. The entire set of statistical analyses will be available to all E-AVR researchers for the interpretation of data.