title: Distinction of non-ischemia inducing versus ischemia inducing coronary stenosis by fluorescent cardiac imaging.
abstract: Intraoperative fluorescent cardiac imaging (FCI) can quantitatively assess myocardial perfusion abnormalities produced by graded flow-limiting coronary stenosis (FLS), but there are no data to distinguish FLS from non flow-limiting stenosis (NFLS) to determine their functional significance. The aim of the study was to evaluate whether non-ischemia inducing NFLS can be quantified and differentiated from FLS by FCI technology. Data are compared to gold standard fluorescent microspheres (FM). 11 domestic pigs of either sex underwent sternotomy. Left anterior descending coronary artery blood-flow was recorded by transit-time flow measurements. After baseline and Adenosine-induced hyperemia, two stenosis of low severity (50 and 90 % NFLS) were produced, followed by FLS (50 %) and total vessel occlusion. Time-dependent fluorescence intensity curves were recorded by FCI. Slope of fluorescence intensity (SFI) and background-subtracted peak fluorescence (BSFI) intensity were calculated and data compared to myocardial blood flow measurements using FM. All NFLS and FLS reduced myocardial perfusion as quantified by FCI showing decreased normalized BSFI and SFI (P < 0.001). Box-plot analysis showed significant difference between NFLS (50 and 90 %) and FLS (50 %) assessed by BSFI (P < 0.001) and SFI (P < 0.001). In each animal, a linear correlation between FM-derived myocardial blood flow and FCI-derived BSFI (r = 0.936, P < 0.001) or SFI (r = 0.942, P < 0.001) was observed during baseline, hyperemia, graded NFLS, and FLS. Both, BSFI (r = 0.789, P < 0.001) and SFI (r = 0.802, P < 0.001) significantly correlated with transit-time flow measurements. FCI quantitative technology is capable of distinguishing between non-ischemia inducing NFLS and ischemia inducing FLS showing a good correlation compared to fluorescent microspheres.
authors.affiliation: Department of Cardiovascular Surgery, University Heart Center Hamburg, Martinistr.52, 20246, Hamburg, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Wipper
authors.affiliation: Department of Cardiovascular Surgery, University Heart Center Hamburg, Martinistr.52, 20246, Hamburg, Germany.
authors.forename: Beate
authors.initials: B
authors.lastname: Reiter
authors.affiliation: Institut für Lasertechnologien in der Medizin und Messtechnik, University Ulm, Ulm, Germany.
authors.forename: Detlef
authors.initials: D
authors.lastname: Russ
authors.affiliation: Department of Cardiovascular Surgery, University Heart Center Hamburg, Martinistr.52, 20246, Hamburg, Germany.
authors.forename: Fabian
authors.initials: F
authors.lastname: Hahnel
authors.affiliation: Department of Medical Biometry and Epidemiology, University Hospital Eppendorf, Hamburg, Germany.
authors.forename: Jan-Felix
authors.initials: JF
authors.lastname: Kersten
authors.affiliation: Department of Cardiovascular Surgery, University Heart Center Hamburg, Martinistr.52, 20246, Hamburg, Germany.
authors.forename: Tilo
authors.initials: T
authors.lastname: Kölbel
authors.affiliation: Department of Cardiovascular Surgery, University Heart Center Hamburg, Martinistr.52, 20246, Hamburg, Germany.
authors.forename: Hermann
authors.initials: H
authors.lastname: Reichenspurner
authors.affiliation: Department of Cardiovascular Surgery, University Heart Center Hamburg, Martinistr.52, 20246, Hamburg, Germany. detter@uke.de.
authors.forename: Christian
authors.initials: C
authors.lastname: Detter
mesh_terms: D000818:Animals; D023921:Coronary Stenosis / Q000150:complications* / Q000175:diagnosis*; D003937:Diagnosis, Differential; D004195:Disease Models, Animal; D005260:Female; D008297:Male; D008863:Microspheres; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000209:etiology*; D061848:Optical Imaging; D015203:Reproducibility of Results; D013552:Swine
keywords: Fluorescent cardiac imaging; Intraoperative quality control; Myocardial ischemia; Myocardial perfusion; Non-flow limiting stenosis