title: Do indices of coronary conductance after reperfusion reflect the extent of salvaged myocardium?
abstract: Existing indices of coronary conductance (hyperemic flow-versus-pressure slope index, FPSI, and zero flow pressure, Pzf) have been developed as measures of microcoronary resistance. These indices, however, refer to cases of normal hearts, and there are no reports studying these indices following acute myocardial infarction. In this study, we investigated whether FPSI and Pzf truly measure the extent of myocardial salvage after successful reperfusion therapy. We also developed a new index of zero pressure flow, Fzp. Nineteen patients who underwent successful reperfusion therapy to the proximal portion of the left anterior descending artery (LAD) were studied. After successful reperfusion therapy, a Doppler wire was placed into the LAD. Aortic pressure was recorded in real time. Results from the aortic pressure and flow meter were combined to produce FPSI, Pzf, and Fzp. All cases underwent a resting thallium (Tl) and BMIPP scintigram within five days of successful reperfusion therapy. Infarcted myocardium was estimated using a severity score calculated from the Tl scintigraphy (TlSS), and the BMIPP (BMIPPSS) was estimated using a severity score. Patients with a TlSS/BMIPPSS ratio of less than 0.4 were assigned to the successful salvage group (group S), while the others were assigned to the failed salvage group (group F). FPSI of group F was 1.91 +/- 0.26 m/sec and of group S was 0.92 +/- 0.43 m/sec (P < 0.01). Pzf of group F was 51 +/- 3 mmHg and of group S was 51 +/- 5 mmHg (NS). Fzp of group F was -98 +/- 16 cm/sec and of group S was -46 +/- 4 cm/sec (P < 0.05). FPSI and the new index of Fzp were useful in estimating the extent of myocardial salvage. Our results suggest that the Pzf index could not differentiate between the two groups.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Shibata
authors.forename: Hisashi
authors.initials: H
authors.lastname: Watanabe
authors.forename: Tetsushi
authors.initials: T
authors.lastname: Tsurusaki
authors.forename: Kousuke
authors.initials: K
authors.lastname: Minai
authors.forename: Takayuki
authors.initials: T
authors.lastname: Ogawa
authors.forename: Keiji
authors.initials: K
authors.lastname: Iwano
authors.forename: Tetsutarou
authors.initials: T
authors.lastname: Tamura
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yoshida
authors.forename: Makoto
authors.initials: M
authors.lastname: Mutou
authors.forename: Kamon
authors.initials: K
authors.lastname: Imai
authors.forename: Toshinobu
authors.initials: T
authors.lastname: Horie
authors.forename: Seibu
authors.initials: S
authors.lastname: Mochizuki
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001783:Blood Flow Velocity; D001794:Blood Pressure; D003326:Coronary Circulation / Q000502:physiology*; D003331:Coronary Vessels / Q000503:physiopathology; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology / Q000628:therapy*; D015425:Myocardial Reperfusion; D009206:Myocardium / Q000473:pathology; D011877:Radionuclide Imaging; D012720:Severity of Illness Index