Guest Editor: Raul Caso (Department of Surgery, MedStar Georgetown University Hospital, Washington, USA) and John F. Lazar (Division of Thoracic Surgery, Georgetown University School of Medicine, Medstar Washington Hospital Center, Washington, USA).

Guest Editor: Aleksander Dokollari (Lankenau Institute for Medical Research), Basel Ramlawi (Lankenau Medical Center, Wynnewood, Philadelphia, USA.), and Gianluigi Bisleri (Division of Cardiac Surgery, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada).