Characterizing the ¿iceberg peak¿ in valvular heart disease: Outcomes and costs of in-hospital procedures in Spain Mercedes Álvarez-Bartolomé; Ignacio Cruz-González; Ana Pardo-Sanz; José Luis Zamorano; Paloma González; Óscar Martínez-Pérez; Jesús Cuervo; Manuel Carnero-Alcázar;