^aDepartment of Cardiovascular, Respiratory, Nephrological, Anaesthetic and Geriatric Sciences, ‘Sapienza’ University of Rome

^bDepartment of Cardiology, Policlinico Casilino, Rome, Italy

Correspondence to Dr Luca Monzo, Department of Cardiovascular, Respiratory, Nephrological, Anaesthetic and Geriatric Sciences, ‘Sapienza’ University, Rome, Italy Tel: +00 39 0623188406; fax: +00 39 0623188408; e-mail: [email protected]

Received 26 December, 2017

Revised 13 April, 2018

Accepted 17 May, 2018

Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Website (www.jcardiovascularmedicine.com).