Prevalence of iron deficiency and its influence on six-minute walk test distance in patients eligible for transcatheter aortic valve implantation. A prospective study - Michał Błaszkiewicz; Krzysztof A. Aleksandrowicz; Małgorzata Mazur; Tomasz G. Witkowski; Michał Kosowski; Piotr Kübler; Krzysztof Reczuch; Marcin Protasiewicz (Advances in Interventional Cardiology)