Nils P. Johnson, MD, MS; Richard L. Kirkeeide, PhD; K. Lance Gould*, MD
Weatherhead PET Center for Preventing and Reversing Atherosclerosis, Division of Cardiology, Department of Medicine, University of Texas Medical School and Memorial Hermann Hospital, Houston, TX, USA
Petraco and colleagues1 have presented the “adjusted” accuracy comparing their new index (instantaneous wave-free ratio, iFR) against the gold standard of fractional flow reserve (FFR). However, Table 2 of their manuscript misrepresents theoretical calculations as clinical observations. Misleading column labels hide the fact from the casual reader that many of its numbers are assumed from a model instead of being measured directly.
Specifically, in three of the four studies (ADVISE registry, ADVISE study, FFR-PET study) FFR values were measured only once, yet the table makes no distinction among the agreement data in its “Repeated FFR measurements” column. Even for the ...