title: A nonsurgical porcine model of left ventricular dysfunction. Validation of myocardial viability using dobutamine stress echocardiography and positron emission tomography.
abstract: BACKGROUND: Although several short-term animal models of stunning and hibernation have been studied extensively, it has been difficult to produce a consistent animal model of chronic hibernation. The aim of the present study was to develop a nonsurgical porcine stent model of coronary stenosis in order to investigate the relationship between chronic dysfunctional myocardium and viability using 2D-echo, dobutamine stress echo (DSE) and positron emission tomography (PET). METHODS AND RESULTS: Focal progressive coronary stenosis was induced by implantation of an oversized stent in the left anterior descending (LAD) and/or circumflex (LCX) coronary artery in a total of 115 pigs, according to various experimental protocols: copper stent in the LAD (group I, n = 5); noncoated stainless steel stent in the LAD combined with balloon overstretch (group II, n = 7); poly(organo)phosphazene-coated stent in the LAD (group III, n = 77); and poly(organo)phosphazene-coated stent in both the LAD and the LCX (group IV, n = 26). Occurrence of left ventricular dysfunction was evaluated weekly by 2D-echo. At the time of left ventricular dysfunction the presence of viable myocardium within the dysfunctional region was investigated with DSE and PET, and confirmed by histology. The degree of coronary artery stenosis was measured by quantitative coronary angiography and morphometry. Severe coronary artery stenosis in the presence of dysfunctional, but viable, myocardium was induced in groups III and IV (47% and 11% of the animals, respectively). CONCLUSIONS: The authors developed a nonsurgical porcine stent model of progressive coronary stenosis using an oversized polymer-coated stent resulting in chronically decreased myocardial function, with residual inotropic reserve and viable myocardium. This condition may arise from repetitive periods of ischemia, or from sustained hypoperfusion, or a combination of these processes eventually leading to myocardial hibernation.
authors.affiliation: Laboratory for Experimental Cardiology, UZ Gasthuisberg, Herestraat 49, 3000 Leuven, Belgium.
authors.forename: Monika
authors.initials: M
authors.lastname: Szilárd
authors.forename: Liesbet
authors.initials: L
authors.lastname: Mesotten
authors.forename: Alex
authors.initials: A
authors.lastname: Maes
authors.forename: Xiaoshun
authors.initials: X
authors.lastname: Liu
authors.forename: Johan
authors.initials: J
authors.lastname: Nuyts
authors.forename: Guy
authors.initials: G
authors.lastname: Bormans
authors.forename: Tjibbe
authors.initials: T
authors.lastname: De Groot
authors.forename: Sorin
authors.initials: S
authors.lastname: Pislaru
authors.forename: Yanming
authors.initials: Y
authors.lastname: Huang
authors.forename: Beiping
authors.initials: B
authors.lastname: Qiang
authors.forename: Gerrit D
authors.initials: GD
authors.lastname: Dispersyn
authors.forename: Marcel
authors.initials: M
authors.lastname: Borgers
authors.forename: Willem
authors.initials: W
authors.lastname: Flameng
authors.forename: Frans
authors.initials: F
authors.lastname: Van De Werf
authors.forename: Luc
authors.initials: L
authors.lastname: Mortelmans
authors.forename: Ivan
authors.initials: I
authors.lastname: De Scheerder