CMR Diffusion Tensor Imaging Provides Novel Imaging Markers of Adverse Myocardial Remodeling in Aortic Stenosis

Objectives - This study sought to determine microstructural cardiac remodeling in aortic stenosis (AS) and its reversibility following valve replacement using cardiovascular magnetic resonance (CMR) diffusion tensor imaging (DTI). Background - Myocardial involvement in AS, such as focal and diffuse fibrosis is associated with worse outcome, even after timely aortic valve replacement (AVR). Alterations of myofiber architecture and myocardial diffusion may precede fibrosis, but its extent and reversibility after AVR are unknown. Methods - Patients with isolated severe AS (n=21, 62% male; mean age 75 years) and sex-matched senior control subjects underwent prospective CMR DTI. Changes in the DTI parameters: mean diffusivity (MD), fractional anisotropy (FA) as well as helix angle (HA) and absolute E2A sheet angle (E2A) were quantified and compared with native T1 and extracellular volume (ECV) as standard CMR markers of myocardial fibrosis. Six months after AVR eleven patients were scheduled for a follow-up CMR. Results - In AS patients, significantly elevated MD (p=0.002) and reduced FA (p<0.001) were measured when compared to controls. Myocyte aggregate orientation exhibited a steeper transmural HA slope (p<0.001) and increased absolute E2A sheet angle (p<0.001) in AS. Six months post AVR, the HA slope (p<0.001) was reduced to the level of healthy controls and MD (p=0.014), FA (p=0.011) and E2A (p=0.003) showed a significant regression towards normal values. In contrast, native T1 was similar in AS and controls and did not change significantly after AVR. ECV showed a non-significant trend (p=0.16) to higher values after AVR. Conclusion - In patients with severe aortic stenosis, CMR DTI provides a set of parameters that identifies structural and diffusion abnormalities, which are largely reversible after AVR. DTI parameters showed proportionally greater changes in response to AS and AVR compared to metrics of myocardial fibrosis and may, therefore, aid risk stratification in earlier stages of severe AS.

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Exploring myocardial fibrosis in severe aortic stenosis: echo, CMR and histology data from FIB-AS study

10.21203/rs.3.rs-1142411/v1 ◽

2021 ◽

Author(s):

Giedrė Balčiūnaitė ◽

Justinas Besusparis ◽

Darius Palionis ◽

Edvardas Žurauskas ◽

Viktor Skorniakov ◽

...

Keyword(s):

Aortic Stenosis ◽

Myocardial Fibrosis ◽

Volume Fraction ◽

Severe Aortic Stenosis ◽

Systolic Dysfunction ◽

Global Longitudinal Strain ◽

Surrogate Marker ◽

Serum Biomarkers ◽

Cardiac Remodelling ◽

Native T1

Abstract PurposeMyocardial fibrosis in aortic stenosis (AS) is associated with worse survival following aortic valve replacement (AVR). We assessed myocardial fibrosis in severe AS patients, integrating echocardiographic, cardiovascular magnetic resonance (CMR) and histological data. MethodsA total of 83 severe AS patients (age 66.4 ± 8.3, 42% male) who were scheduled for surgical AVR underwent CMR with late gadolinium enhancement (LGE) and T1 mapping and global longitudinal strain (GLS) analysis. Collagen volume fraction (CVF) was measured in myocardial biopsies (71) that were sampled at the time of AVR. ResultsCVF correlated with imaging and serum biomarkers of LV systolic dysfunction and left side chamber enlargement and was higher in the sub-endocardium compared with midmyocardium (p<0.001). CVF median values were higher in LGE-positive versus LGE-negative patients [28.7% (19-33) vs 20.7% (15-30), respectively, p=0.040]. GLS was associated with invasively (CVF; r=-0.303, p=0.013) and non-invasively (native T1; r=-0.321, p<0.05) measured myocardial fibrosis. GLS and native T1 correlated with parameters of adverse LV remodelling, systolic and diastolic dysfunction and serum biomarkers of heart failure and myocardial injury. ConclusionOur data highlight the role of myocardial fibrosis in adverse cardiac remodelling in AS. GLS has potential as a surrogate marker of myocardial fibrosis, and high native T1 and low GLS values differentiated patients with more advanced cardiac remodelling.

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Myocardial extracellular volume quantification using CT for the identification of occult cardiac amyloidosis in patients with severe aortic stenosis referred for transcatheter aortic valve replacement

Amyloid ◽

10.1080/13506129.2019.1597701 ◽

2019 ◽

Vol 26 (2) ◽

pp. 97-98 ◽

Cited By ~ 3

Author(s):

Seitaro Oda ◽

Seiji Takashio ◽

Suguru Nagamatsu ◽

Takayoshi Yamashita ◽

Ryutaro Uchimura ◽

...

Keyword(s):

Aortic Valve ◽

Aortic Stenosis ◽

Aortic Valve Replacement ◽

Valve Replacement ◽

Transcatheter Aortic Valve Replacement ◽

Cardiac Amyloidosis ◽

Severe Aortic Stenosis ◽

Extracellular Volume ◽

Transcatheter Aortic Valve

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Pre- and post-contrast T1 mapping for detection of myocardial fibrosis in severe aortic stenosis before and after aortic valve replacement

Journal of Cardiovascular Magnetic Resonance ◽

10.1186/1532-429x-16-s1-m7 ◽

2014 ◽

Vol 16 (S1) ◽

Author(s):

Emmanuelle Vermes ◽

Aurelia Ros ◽

Julien Pucheux ◽

Anne Delhommais ◽

Daniel Alison ◽

...

Keyword(s):

Aortic Valve ◽

Aortic Stenosis ◽

Aortic Valve Replacement ◽

Valve Replacement ◽

Myocardial Fibrosis ◽

T1 Mapping ◽

Severe Aortic Stenosis ◽

Post Contrast ◽

Before And After

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T1 Mapping for Noninvasively Detecting Diffuse Fibrosis in Severe Aortic Stenosis

Journal of Medical Imaging and Health Informatics ◽

10.1166/jmihi.2020.3076 ◽

2020 ◽

Vol 10 (7) ◽

pp. 1534-1539

Author(s):

Jiajun Xie ◽

Xuhua Jian ◽

Qiyang Lu ◽

Jinxiu Meng ◽

Yu-Hsiang Juan ◽

...

Keyword(s):

Aortic Stenosis ◽

Cardiac Mri ◽

T1 Mapping ◽

Volume Fraction ◽

Severe Aortic Stenosis ◽

Extracellular Volume ◽

Extracellular Volume Fraction ◽

Left Ventricular ◽

Diffuse Fibrosis ◽

Mapping Technique

Purpose: To evaluate myocardial diffuse fibrosis in severe aortic stenosis (SAS) with cardiac magnetic resonance imaging (MRI) T1 mapping technique. Methods: Twenty-seven SAS patients and 15 controls were enrolled and performed cardiac MRI. Left ventricular (LV) structure, function and T1-derived parameters were measured to compare between SAS group and the controls. Correlation between T1-derived parameters and the extent of histologic fibrosis was performed in 15 patients who underwent aortic valve replacement surgery and myocardial biopsy. Results: The SAS group had LV remodeling with ventricular dilatation, hypertrophy, and contractile dysfunction. The native T1 (1336.2±62.5 ms vs. 1277.6±40.7 ms, p = 0.002) and extracellular volume fraction (ECV%) (26.7±2.2% vs. 24.9±2.2%, p = 0.018) were elevated in the SAS in comparison to the controls. Only ECV and λ correlated with the extent of fibrosis as measured by histology. Conclusion: Cardiac MRI with T1 mapping provides a noninvasive approach to evaluate LV myocardial diffuse fibrosis in SAS.

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