Improving outpatient care for heart failure through digital innovation: a feasibility study oleh David O. Arnar, Saemundur J. Oddsson, Thrudur Gunnarsdottir, Gudbjorg Jona Gudlaugsdottir, Elias Freyr Gudmundsson, Audur Ketilsdóttir, Hulda Halldorsdottir, Thordis Jona Hrafnkelsdottir, Hallur Hallsson, Maria L. Amundadottir, Tryggvi Thorgeirsson