A Collection of Position Statements and Opinions on e-cigarette use and cardiovascular disease: On behalf of the Working Group on Epidemiology of the Hellenic Atherosclerosis Society Venetia Notara, Vassiliki Bobolou, Alexandra Foscolou, Matina Kouvari, Eleni Chelioti, Emmanuella Magriplis, Demosthenes Panagiotakos