1. Department of Cardiology, Hospital Universitario Marqués de Valdecilla, Avenida Valdecilla 25, Santander 39008, Spain
2. Department of Cardiovascular Surgery, Hospital Universitario Marqués de Valdecilla, Avenida Valdecilla 25, Santander 39008, Spain
3. Department of Cardiology, Hospital Universitario Donostia, Paseo Dr Begiristain 107, Donostia 20014, Spain