title: The fractional flow reserve gray zone has never been so narrow.
authors.affiliation: Division of Cardiology, Department of Advanced Biomedical Sciences, University of Naples Federico II, Naples, Italy.
authors.forename: Teresa
authors.initials: T
authors.lastname: Strisciuglio
authors.affiliation: Division of Cardiology, Department of Advanced Biomedical Sciences, University of Naples Federico II, Naples, Italy;; Cardiovascular Center Aalst, Aalst, Belgium.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Barbato