Perceval sutureless bioprosthesis versus Trifecta sutured bioprosthesis for aortic valve replacement: immediate results of the Perfecta study - Paolo Nardi; Claudia Altieri; Calogera Pisano; Dario Buioni; Federico Agneni; Giorgia Grizzi; Martin Dakli; Alessandro Cristian Salvati; Mattia Scognamiglio; Carlo Bassano; Giovanni Ruvolo (Polish Journal of Thoracic and Cardiovascular Surgery)