MedStar Union Memorial Hospital, Baltimore MD, USA. Electronic address: john.wang@medstar.net. Centre Hôpital Universitaire Rangueil, Toulouse, France. Electronic address: carrie.didier@chu-toulouse.fr. Hospital Clinic, University of Barcelona, Spain. Electronic address: MASOTTI@clinic.ub.es. Pauls Stradins Clinical University Hospital, University of Latvia, Riga, Latvia. Electronic address: a.a.erglis@stradini.lv. Arkansas Heart Hospital, Little Rock, AR. Electronic address: David.Mego@arheart.com. University of Vermont Medical Center, Burlington VT, USA. Electronic address: Matthew.Watkins@vtmednet.org. Boston Scientific, Marlborough MA USA. Electronic address: Paul.underwood@bsci.com. Boston Scientific, Marlborough MA USA. Electronic address: Dominic.allocco@bsci.com. Kerckhoff Heart and Thoraxcenter, Bad Nauheim, Germany. Electronic address: C.Hamm@kerckhoff-klinik.de.