title: Facing the complexity of ischaemic heart disease with intracoronary pressure and flow measurements: beyond fractional flow reserve interrogation of the coronary circulation.
abstract: OBJECTIVE
  The purpose of this study is to summarize cumulative evidence suggesting that the combination of fractional flow reserve (FFR), coronary flow reserve (CFR) and the index of microcirculatory resistance (IMR) might provide a more comprehensive invasive assessment of ischaemic heart disease (IHD).
  
  
  RESULTS
  Myocardial flow impairment in IHD results from both obstructive and nonobstructive causes. However, its diagnosis is primarily stenosis-centred. Although FFR provides valuable information on obstructive disease, its theoretical framework largely neglects the importance of nonobstructive concomitant involvement. Substantial evidence suggests, however, that nonobstructive IHD has important prognostic implications, and CFR and IMR are readily available tools for its concomitant diagnosis. Furthermore, CFR and IMR have independently been shown to improve IHD risk stratification. Further studies should address whether this more comprehensive IHD diagnosis, derived from the combination of FFR, CFR and IMR, may improve prognostic risk stratification and guide therapeutic strategies aiming for both obstructive and nonobstructive IHD involvement.
  
  
  CONCLUSIONS
  FFR, CFR and IMR have independently been shown to improve IHD risk stratification. Their combined use is feasible and appealing, and might lead to a more comprehensive invasive assessment of IHD.
authors.affiliation: aCardiovascular Institute, Hospital Clínico San Carlos bCentro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain cAMC Heart Centre, Academic Medical Centre - University of Amsterdam, Amsterdam dThorax Center, Erasmus Medical Center, Rotterdam, the Netherlands eFaculty of Medicine, Complutense University of Madrid, Madrid, Spain.
authors.forename: Mauro
authors.initials: M
authors.lastname: Echavarría-Pinto
authors.forename: Tim P
authors.initials: TP
authors.lastname: van de Hoef
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Serruys
authors.forename: Jan J
authors.initials: JJ
authors.lastname: Piek
authors.forename: Javier
authors.initials: J
authors.lastname: Escaned
mesh_terms: D001794:Blood Pressure / Q000502:physiology*; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000503:physiopathology*; D053805:Fractional Flow Reserve, Myocardial / Q000502:physiology*; D006801:Humans; D017202:Myocardial Ischemia / Q000175:diagnosis / Q000503:physiopathology*; D011379:Prognosis; D012039:Regional Blood Flow / Q000502:physiology*; D012720:Severity of Illness Index