title: Myocardial reverse remodeling after pressure unloading is associated with maintained cardiac mechanoenergetics in a rat model of left ventricular hypertrophy.
abstract: Pressure unloading represents the only effective therapy in increased afterload-induced left ventricular hypertrophy (LVH) as it leads to myocardial reverse remodeling (reduction of increased left ventricular mass, attenuated myocardial fibrosis) and preserved cardiac function. However, the effect of myocardial reverse remodeling on cardiac mechanoenergetics has not been elucidated. Therefore, we aimed to provide a detailed hemodynamic characterization in a rat model of LVH undergoing pressure unloading. Pressure overload was induced in Sprague-Dawley rats by abdominal aortic banding for 6 (AB 6th wk) or 12 wk (AB 12th wk). Sham-operated animals served as controls. Aortic debanding procedure was performed after the 6th experimental week (debanded 12th wk) to investigate the regression of LVH. Pressure unloading resulted in significant reduction of LVH (heart weight-to-tibial length ratio: 0.38 ± 0.01 vs. 0.58 ± 0.02 g/mm, cardiomyocyte diameter: 18.3 ± 0.1 vs. 24.1 ± 0.8 μm debanded 12th wk vs. AB 12th wk, P < 0.05), attenuated the extracellular matrix remodeling (Masson's score: 1.37 ± 0.13 vs. 1.73 ± 0.10, debanded 12th wk vs. AB 12th wk, P < 0.05), provided protection against the diastolic dysfunction, and reversed the maladaptive contractility augmentation (slope of end-systolic pressure-volume relationship: 1.39 ± 0.24 vs. 2.04 ± 0.09 mmHg/μl, P < 0.05 debanded 12th wk vs. AB 6th wk, P < 0.05). In addition, myocardial reverse remodeling was also associated with preserved ventriculoarterial coupling and increased mechanical efficiency (50.6 ± 2.8 vs. 38.9 ± 2.5%, debanded 12th wk vs. AB 12th wk, P < 0.05), indicating a complete functional and mechanoenergetic recovery. According to our best knowledge, this is the first study demonstrating that the regression of LVH is accompanied by maintained cardiac mechanoenergetics.
authors.affiliation: Department of Cardiac Surgery, University of Heidelberg, Heidelberg, Germany; Heart and Vascular Center, Semmelweis University, Budapest, Hungary; and ruppertmis@gmail.com.
authors.forename: Mihály
authors.initials: M
authors.lastname: Ruppert
authors.affiliation: Department of Cardiac Surgery, University of Heidelberg, Heidelberg, Germany;
authors.forename: Sevil
authors.initials: S
authors.lastname: Korkmaz-Icöz
authors.affiliation: Department of Cardiac Surgery, University of Heidelberg, Heidelberg, Germany;
authors.forename: Shiliang
authors.initials: S
authors.lastname: Li
authors.affiliation: Heart and Vascular Center, Semmelweis University, Budapest, Hungary; and.
authors.forename: Balázs Tamás
authors.initials: BT
authors.lastname: Németh
authors.affiliation: Department of Cardiac Surgery, University of Heidelberg, Heidelberg, Germany;
authors.forename: Péter
authors.initials: P
authors.lastname: Hegedűs
authors.affiliation: Department of Cardiac Surgery, University of Heidelberg, Heidelberg, Germany;
authors.forename: Paige
authors.initials: P
authors.lastname: Brlecic
authors.affiliation: Heart and Vascular Center, Semmelweis University, Budapest, Hungary; and.
authors.forename: Csaba
authors.initials: C
authors.lastname: Mátyás
authors.affiliation: Department of Internal Medicine I, University of Heidelberg, Heidelberg, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Zorn
authors.affiliation: Heart and Vascular Center, Semmelweis University, Budapest, Hungary; and.
authors.forename: Béla
authors.initials: B
authors.lastname: Merkely
authors.affiliation: Department of Cardiac Surgery, University of Heidelberg, Heidelberg, Germany;
authors.forename: Matthias
authors.initials: M
authors.lastname: Karck
authors.affiliation: Heart and Vascular Center, Semmelweis University, Budapest, Hungary; and.
authors.forename: Tamás
authors.initials: T
authors.lastname: Radovits
authors.affiliation: Department of Cardiac Surgery, University of Heidelberg, Heidelberg, Germany;
authors.forename: Gábor
authors.initials: G
authors.lastname: Szabó
mesh_terms: D000818:Animals; D001011:Aorta / Q000601:surgery; D015153:Blotting, Western; D004452:Echocardiography; D004734:Energy Metabolism; D005355:Fibrosis; D006439:Hemodynamics; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology; D008297:Male; D009200:Myocardial Contraction; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D032383:Myocytes, Cardiac / Q000473:pathology; D011312:Pressure; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020257:Ventricular Remodeling
chemical_list: D012333:RNA, Messenger
keywords: cardiac contractility; cardiac mechanoenergetics; diastolic dysfunction; pressure overload-induced cardiac hypertrophy; pressure unloading; pressure-volume analysis