title: Incremental prognostic value of coronary flow reserve assessed with single-photon emission computed tomography.
abstract: BACKGROUND
  We assessed the prognostic value of coronary flow reserve (CFR) estimated by single-photon emission computed tomography (SPECT) in patients with suspected myocardial ischemia.
  
  
  RESULTS
  Myocardial perfusion and CFR were assessed in 106 patients using dipyridamole/rest Tc-99m sestamibi SPECT and follow-up was obtained in 103 (97%) patients. Four early revascularized patients were excluded and 99 were assigned to normal (summed stress score <3) vs abnormal myocardial perfusion and to normal (≥2.0) vs abnormal CFR. During the follow-up (5.8 ± 2.1 years), 28 patients experienced a cardiac event (cardiac death, nonfatal myocardial infarction, and late revascularization). Abnormal perfusion (P < .01) and abnormal CFR (P < .05) were independent predictors of cardiac events at Cox proportional hazard regression analysis. Also in patients with normal perfusion, abnormal CFR was associated with a higher annual event rate compared with normal CFR (5.2% vs 0.7%; P < .05). CFR data improved the prognostic power of the model including clinical and myocardial perfusion data increasing the global chi-square from 18.6 to 22.8 (P < .05). Finally, at parametric survival analysis, in patients with normal perfusion the time to achieve ≥2% risk of events was >60 months in those with normal and <12 months in those with abnormal CFR.
  
  
  CONCLUSIONS
  Myocardial perfusion findings and CFR at SPECT imaging are both independent predictors of cardiac events. Estimated CFR provides incremental prognostic information over those obtained from clinical and myocardial perfusion data, particularly in patients with normal perfusion findings.
authors.affiliation: SDN Foundation, Institute of Diagnostic and Nuclear Development, Naples, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Daniele
authors.forename: Carmela
authors.initials: C
authors.lastname: Nappi
authors.forename: Wanda
authors.initials: W
authors.lastname: Acampa
authors.forename: Giovanni
authors.initials: G
authors.lastname: Storto
authors.forename: Teresa
authors.initials: T
authors.lastname: Pellegrino
authors.forename: Francesca
authors.initials: F
authors.lastname: Ricci
authors.forename: Evgjeni
authors.initials: E
authors.lastname: Xhoxhi
authors.forename: Francesco
authors.initials: F
authors.lastname: Porcaro
authors.forename: Mario
authors.initials: M
authors.lastname: Petretta
authors.forename: Alberto
authors.initials: A
authors.lastname: Cuocolo
mesh_terms: D000368:Aged; D003326:Coronary Circulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging; D011379:Prognosis; D016016:Proportional Hazards Models; D015899:Tomography, Emission-Computed, Single-Photon