title: Validation of collateral fractional flow reserve by myocardial perfusion imaging.
abstract: BACKGROUND
  Collateral fractional flow reserve (FFR(coll)) is an index to quantify collateral blood flow, derived from coronary pressure measurements. Although well defined theoretically, its direct validation by myocardial perfusion imaging has not been established so far. Validating this index by myocardial perfusion imaging is the main aim of this study.
  
  
  RESULTS
  Twenty-four consecutive patients with stable angina and single left anterior descending artery stenosis underwent simultaneous measurement of aortic pressure (P(a)), coronary wedge pressure (P(w)), and central venous pressure (P(v)) during balloon inflation. FFR(coll) was calculated and compared with the extent and severity of the defect during coronary occlusion using (99m)Tc-sestamibi imaging at balloon inflation of the respective coronary artery. Although the pressure-derived collateral indexes (P(w), P(w)/P(a), and FFR(coll)) ranged widely, they were closely correlated with extent and severity scores of the nuclear occlusion images and superior to the ECG for that purpose. Of all parameters, FFR(coll) correlated best with the severity score at imaging (r=-0.88), followed by the P(w)/P(a) ratio (r=-0.74) or P(w) alone (r=-0.69).
  
  
  CONCLUSIONS
  FFR(coll), calculated from coronary pressure during balloon occlusion, is highly correlated with the extent and severity of the defect at myocardial perfusion of the territory of the occluded artery and can be used for quantitative assessment of collateral blood flow in conscious humans.
authors.affiliation: Department of Cardiology, Prefectural Gifu Hospital, Gifu University School of Medicine, Gifu City, Japan. matsuo@iri.rd.pref.gifu.jp
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Matsuo
authors.forename: Sachiro
authors.initials: S
authors.lastname: Watanabe
authors.forename: Tohru
authors.initials: T
authors.lastname: Kadosaki
authors.forename: Takahiko
authors.initials: T
authors.lastname: Yamaki
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Tanaka
authors.forename: Shuusaku
authors.initials: S
authors.lastname: Miyata
authors.forename: Tomonori
authors.initials: T
authors.lastname: Segawa
authors.forename: Yukihiko
authors.initials: Y
authors.lastname: Matsuno
authors.forename: Masaaki
authors.initials: M
authors.lastname: Tomita
authors.forename: Hisayoshi
authors.initials: H
authors.lastname: Fujiwara
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000787:Angina Pectoris / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D015906:Angioplasty, Balloon, Coronary; D001011:Aorta; D001783:Blood Flow Velocity; D001794:Blood Pressure; D003097:Collateral Circulation; D017023:Coronary Angiography; D003326:Coronary Circulation; D023921:Coronary Stenosis / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D003331:Coronary Vessels / Q000000981:diagnostic imaging; D004562:Electrocardiography; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011877:Radionuclide Imaging; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D017256:Technetium Tc 99m Sestamibi
chemical_list: D017256:Technetium Tc 99m Sestamibi