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Ku MC, Kober F, Lai YC, Pohlmann A, Qadri F, Bader M, Carrier L, Niendorf T. Cardiovascular magnetic resonance detects microvascular dysfunction in a mouse model of hypertrophic cardiomyopathy. J Cardiovasc Magn Reson 2021; 23:63. [PMID: 34053450 PMCID: PMC8166121 DOI: 10.1186/s12968-021-00754-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 04/06/2021] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Hypertrophic cardiomyopathy (HCM) related myocardial vascular remodelling may lead to the reduction of myocardial blood supply and a subsequent progressive loss of cardiac function. This process has been difficult to observe and thus their connection remains unclear. Here we used non-invasive myocardial blood flow sensitive CMR to show an impairment of resting myocardial perfusion in a mouse model of naturally occurring HCM. METHODS We used a mouse model (DBA/2 J; D2 mouse strain) that spontaneously carries variants in the two most susceptible HCM genes-Mybpc3 and Myh7 and bears the key features of human HCM. The C57BL/6 J (B6) was used as a reference strain. Mice with either B6 or D2 backgrounds (male: n = 4, female: n = 4) underwent cine-CMR for functional assessment at 9.4 T. Left ventricular (LV) wall thickness was measured in end diastolic phase by cine-CMR. Quantitative myocardial perfusion maps (male: n = 5, female: n = 5 in each group) were acquired from arterial spin labelling (cine ASL-CMR) at rest. Myocardial perfusion values were measured by delineating different regions of interest based on the LV segmentation model in the mid ventricle of the LV myocardium. Directly after the CMR, the mouse hearts were removed for histological assessments to confirm the incidence of myocardial interstitial fibrosis (n = 8 in each group) and small vessel remodelling such as vessel density (n = 6 in each group) and perivascular fibrosis (n = 8 in each group). RESULTS LV hypertrophy was more pronounced in D2 than in B6 mice (male: D2 LV wall thickness = 1.3 ± 0.1 mm vs B6 LV wall thickness = 1.0 ± 0.0 mm, p < 0.001; female: D2 LV wall thickness = 1.0 ± 0.1 mm vs B6 LV wall thickness = 0.8 ± 0.1 mm, p < 0.01). The resting global myocardial perfusion (myocardial blood flow; MBF) was lower in D2 than in B6 mice (end-diastole: D2 MBFglobal = 7.5 ± 0.6 vs B6 MBFglobal = 9.3 ± 1.6 ml/g/min, p < 0.05; end-systole: D2 MBFglobal = 6.6 ± 0.8 vs B6 MBFglobal = 8.2 ± 2.6 ml/g/min, p < 0.01). This myocardial microvascular dysfunction was observed and associated with a reduction in regional MBF, mainly in the interventricular septal and inferior areas of the myocardium. Immunofluorescence revealed a lower number of vessel densities in D2 than in B6 (D2 capillary = 31.0 ± 3.8% vs B6 capillary = 40.7 ± 4.6%, p < 0.05). Myocardial collagen volume fraction (CVF) was significantly higher in D2 LV versus B6 LV mice (D2 CVF = 3.7 ± 1.4% vs B6 CVF = 1.7 ± 0.7%, p < 0.01). Furthermore, a higher ratio of perivascular fibrosis (PFR) was found in D2 than in B6 mice (D2 PFR = 2.3 ± 1.0%, B6 PFR = 0.8 ± 0.4%, p < 0.01). CONCLUSIONS Our work describes an imaging marker using cine ASL-CMR with a potential to monitor vascular and myocardial remodelling in HCM.
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Affiliation(s)
- Min-Chi Ku
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Robert-Rössle Strasse 10, 13125, Berlin, Germany.
- DZHK (German Centre for Cardiovascular Research), Partner site Berlin, Berlin, Germany.
| | - Frank Kober
- Centre de Résonance Magnétique Biologique et Médicale (CRMBM), Aix-Marseille University, CNRS, Marseille, France
| | - Yi-Ching Lai
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Robert-Rössle Strasse 10, 13125, Berlin, Germany
| | - Andreas Pohlmann
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Robert-Rössle Strasse 10, 13125, Berlin, Germany
| | - Fatimunnisa Qadri
- Molecular Biology of Peptide Hormones, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Michael Bader
- DZHK (German Centre for Cardiovascular Research), Partner site Berlin, Berlin, Germany
- Molecular Biology of Peptide Hormones, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Lucie Carrier
- Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner site Hamburg/Kiel/Lübeck, Berlin, Germany
| | - Thoralf Niendorf
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Robert-Rössle Strasse 10, 13125, Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), Partner site Berlin, Berlin, Germany
- Experimental and Clinical Research Center (ECRC), A Joint Cooperation between the Charité Medical Faculty and the Max-Delbrück Center for Molecular Medicine, Berlin, Germany
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Kwiecinski J, Lennen RJ, Gray GA, Borthwick G, Boswell L, Baker AH, Newby DE, Dweck MR, Jansen MA. Progression and regression of left ventricular hypertrophy and myocardial fibrosis in a mouse model of hypertension and concomitant cardiomyopathy. J Cardiovasc Magn Reson 2020; 22:57. [PMID: 32758255 PMCID: PMC7409657 DOI: 10.1186/s12968-020-00655-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 07/13/2020] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Myocardial fibrosis is observed in multiple cardiac conditions including hypertension and aortic stenosis. Excessive fibrosis is associated with adverse clinical outcomes, but longitudinal human data regarding changes in left ventricular remodelling and fibrosis over time are sparse because of the slow progression, thereby making longitudinal studies challenging. The purpose of this study was to establish and characterize a mouse model to study the development and regression of left ventricular hypertrophy and myocardial fibrosis in response to increased blood pressure and to understand how these processes reverse remodel following normalisation of blood pressure. METHODS We performed a longitudinal study with serial cardiovascular magnetic resonance (CMR) imaging every 2 weeks in mice (n = 31) subjected to angiotensin II-induced hypertension for 6 weeks and investigated reverse remodelling following normalisation of afterload beyond 6 weeks (n = 9). Left ventricular (LV) volumes, mass, and function as well as myocardial fibrosis were measured using cine CMR and the extracellular volume fraction (ECV) s. RESULTS Increased blood pressure (65 ± 12 vs 85 ± 9 mmHg; p < 0.001) resulted in higher indices of LV hypertrophy (0.09 [0.08, 0.10] vs 0.12 [0.11, 0.14] g; p < 0.001) and myocardial fibrosis (ECV: 0.24 ± 0.03 vs 0.30 ± 0.02; p < 0.001) whilst LV ejection fraction fell (LVEF, 59.3 [57.6, 59.9] vs 46.9 [38.5, 49.6] %; p < 0.001). We found a strong correlation between ECV and histological myocardial fibrosis (r = 0.89, p < 0.001). Following cessation of angiotensin II and normalisation of blood pressure (69 ± 5 vs baseline 65 ± 12 mmHg; p = 0.42), LV mass (0.11 [0.10, 0.12] vs 0.09 [0.08, 0.11] g), ECV (0.30 ± 0.02 vs 0.27 ± 0.02) and LVEF (51.1 [42.9, 52.8] vs 59.3 [57.6, 59.9] %) improved but remained impaired compared to baseline (p < 0.05 for all). There was a strong inverse correlation between LVEF and %ECV during both systemic hypertension (r = - 0.88, p < 0.001) and the increases in ECV observed in the first two weeks of increased blood pressure predicted the reduction in LVEF after 6 weeks (r = - 0.77, p < 0.001). CONCLUSIONS We have established and characterized angiotensin II infusion and repeated CMR imaging as a model of LV hypertrophy and reverse remodelling in response to systemic hypertension. Changes in myocardial fibrosis and alterations in cardiac function are only partially reversible following relief of hypertension.
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Affiliation(s)
- Jacek Kwiecinski
- Centre for Cardiovascular Science, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - Ross J Lennen
- Centre for Cardiovascular Science, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - Gillian A Gray
- Centre for Cardiovascular Science, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - Gary Borthwick
- Centre for Cardiovascular Science, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - Lyndsey Boswell
- Centre for Reproductive Health, University of Edinburgh, The Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, UK
| | - Andrew H Baker
- Centre for Cardiovascular Science, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - David E Newby
- Centre for Cardiovascular Science, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - Marc R Dweck
- Centre for Cardiovascular Science, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - Maurits A Jansen
- Centre for Cardiovascular Science, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK.
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Agafonova IG, Kotel'nikov VN, Geltser BI. Magnetic Resonance Imaging in Assessment of Cardiac Remodeling in Rats with Experimental Arterial Hypertension. Bull Exp Biol Med 2019; 167:320-324. [PMID: 31346866 DOI: 10.1007/s10517-019-04518-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Indexed: 11/28/2022]
Abstract
Magnetic resonance imaging was employed to examine the morphofunctional status of myocardium in Wistar rats with multifactor cardiovasorenal model of arterial hypertension. In 3 months after the onset of experiment, the rats demonstrated a pronounced hypertrophy in left ventricular myocardium mostly due to thickening of the posterior and lateral walls against the background of relatively stable thickness of ventricular septum. The left ventricular endsystolic volume markedly increased in parallel with moderate increase of the end-diastolic volume. The standard calculated indices were used for precise assessment of the type of remodeling of individual myocardial structures. The study showed that multifactor arterial hypertension model was characterized by domination of hypertrophic mode of the left ventricular remodeling, whereas the concentric variant was observed more rarely by 2.5 times. The greatest alterations were observed in the posterior and lateral walls of the left ventricle, which could result from the hemodynamic effects of hypervolemic arterial hypertension.
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Affiliation(s)
- I G Agafonova
- G. B. Elyakov Pacific Ocean Institute of Bioorganic Chemistry, Far-East Division of the Russian Academy of Sciences, Vladivostok, Russia.
| | | | - B I Geltser
- Far-Eastern Federal University, Vladivostok, Russia
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