title: Noninvasive stratification of postinfarction rats based on the degree of cardiac dysfunction using magnetic resonance imaging and echocardiography.
abstract: The myocardial infarction (MI) rat model plays a crucial role in modern cardiovascular research, but the inherent heterogeneity of this model represents a challenge. We sought to identify subgroups among the post-MI rats and establish simple noninvasive stratification protocols for such subgroups. Six weeks after induction of MI, 49 rats underwent noninvasive examinations using magnetic resonance imaging (MRI) and echocardiography. Twelve sham-operated rats served as controls. Increased end-diastolic left ventricular (LV) pressure and lung weight served as indicators for congestive heart failure (CHF). A clustering algorithm using 13 noninvasive and invasive parameters was used to identify distinct groups among the animals. The cluster analysis revealed four distinct post-MI phenotypes; two without congestion but with different degree of LV dilatation, and two with different degree of congestion and right ventricular (RV) affection. Among the MRI parameters, RV mass emerged as robust noninvasive marker of CHF with 100% specificity/sensitivity. Moreover, LV infarct size and RV ejection fraction further predicted subgroup among the non-CHF and CHF rats with excellent specificity/sensitivity. Of the echocardiography parameters, left atrial diameter predicted CHF. Moreover, LV end-diastolic diameter predicted the subgroups among the non-CHF rats. We propose two simple noninvasive schemes to stratify post-MI rats, based on the degree of heart failure; one for MRI and one for echocardiography.NEW & NOTEWORTHYIn vivo phenotyping of rats is essential for robust and reliable data. Here, we present two simple noninvasive schemes for the stratification of postinfarction rats based on the degree of heart failure: one using magnetic resonance imaging and one based on echocardiography.
authors.affiliation: Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway; and j.m.aronsen@medisin.uio.no.|Bjørknes College, Oslo, Norway.
authors.forename: Jan Magnus
authors.initials: JM
authors.lastname: Aronsen
authors.affiliation: Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway; and.
authors.forename: Emil Knut Stenersen
authors.initials: EKS
authors.lastname: Espe
authors.affiliation: Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway; and.
authors.forename: Kristine
authors.initials: K
authors.lastname: Skårdal
authors.affiliation: Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway; and.
authors.forename: Almira
authors.initials: A
authors.lastname: Hasic
authors.affiliation: Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway; and.
authors.forename: Lili
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway; and.
authors.forename: Ivar
authors.initials: I
authors.lastname: Sjaastad
mesh_terms: D000465:Algorithms; D000818:Animals; D002311:Cardiomyopathy, Dilated / Q000503:physiopathology; D004452:Echocardiography / Q000379:methods*; D006321:Heart / Q000503:physiopathology*; D006334:Heart Function Tests; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D051381:Rats; D017208:Rats, Wistar; D013318:Stroke Volume; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology; D016277:Ventricular Function, Left
keywords: congestive heart failure; echocardiography; magnetic resonance imaging; myocardial infarction; rats