Erratum to: 'Left ventricular twist mechanics and its relation with aortic stiffness in chronic kidney disease patients without overt cardiovascular disease'. Issue 1 (December 2015) - Sulemane, Samir; Panoulas, Vasileios; Konstantinou, Klio; Bratsas, Athanasios; Grapsa, Julia; Tam, Frederick; Brown, Edwina; Nihoyannopoulos, Petros