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Relative Apical Sparing of Myocardial Longitudinal Strain Is Explained by Regional Differences in Total Amyloid Mass Rather Than the Proportion of Amyloid Deposits.
- Source :
-
JACC. Cardiovascular imaging [JACC Cardiovasc Imaging] 2019 Jul; Vol. 12 (7 Pt 1), pp. 1165-1173. Date of Electronic Publication: 2018 Aug 15. - Publication Year :
- 2019
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Abstract
- Objectives: This study sought to test whether relative apical sparing (RELAPS) of left ventricular (LV) longitudinal strain (LS) in cardiac amyloidosis (CA) is explained by regional differences in markers of amyloid burden ( <superscript>18</superscript> F-florbetapir uptake by positron emission tomography [PET] and/or extracellular volume fraction [ECV] by cardiac magnetic resonance (CMR)].<br />Background: Further knowledge of the pathophysiological basis for RELAPS can help understand the adverse outcomes associated with apical LS impairment.<br />Methods: This was a prospective study of 32 subjects (age 62 ± 7 years; 50% males) with light chain CA. All subjects underwent two-dimensional echocardiography for LS estimation and <superscript>18</superscript> F-florbetapir PET for quantification of LV florbetapir retention index (RI). A subset also underwent CMR (n = 22) for ECV quantification. Extracellular LV mass (LV mass*ECV) and total florbetapir binding (extracellular LV mass*florbetapir RI) were also calculated. All parameters were measured globally and regionally (base, mid, and apex).<br />Results: There was a significant base-to-apex gradient in LS (-7.4 ± 3.2% vs. -8.6 ± 4.0% vs. -20.8 ± 6.6%; p < 0.0001), maximal LV wall thickness (15.7 ± 1.9 cm vs. 15.4 ± 2.9 cm vs. 10.1 ± 2.4 cm; p < 0.0001), and LV mass (74.8 ± 21.2 g vs. 60.8 ± 17.3 g vs. 23.4 ± 6.2 g; p < 0.0001). In contrast, florbetapir RI (0.089 ± 0.03 μmol/min/g vs. 0.097 ± 0.03 μmol/min/g vs. 0.085 ± 0.03 μmol/min/g; p = 0.45) and ECV (0.53 ± 0.08 vs. 0.49 ± 0.08 vs. 0.49 ± 0.07; p = 0.15) showed no significant base-to-apex gradient in the tissue concentration or proportion of amyloid infiltration, whereas markers of total amyloid load, such as total florbetapir binding (3.4 ± 1.7 μmol/min vs. 2.8 ± 1.5 μmol/min vs. 0.93 ± 0.49 μmol/min; p < 0.0001) and extracellular LV mass (40.0 ± 15.6 g vs. 30.2 ± 10.9 g vs. 11.6 ± 3.9 g; p < 0.0001), did show a marked base-to-apex gradient.<br />Conclusions: Segmental differences in the distribution of the total amyloid mass, rather than the proportion of amyloid deposits, appear to explain the marked regional differences in LS in CA. Although these 2 matrices are clearly related concepts, they should not be used interchangeably.<br /> (Copyright © 2019 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)
- Subjects :
- Aged
Amyloidosis pathology
Amyloidosis physiopathology
Aniline Compounds administration & dosage
Cardiomyopathies pathology
Cardiomyopathies physiopathology
Echocardiography
Ethylene Glycols administration & dosage
Female
Humans
Male
Middle Aged
Myocardium chemistry
Predictive Value of Tests
Prospective Studies
Radiopharmaceuticals administration & dosage
Amyloid analysis
Amyloidosis diagnostic imaging
Cardiomyopathies diagnosis
Magnetic Resonance Imaging, Cine
Myocardium pathology
Positron-Emission Tomography
Stroke Volume
Ventricular Function, Left
Subjects
Details
- Language :
- English
- ISSN :
- 1876-7591
- Volume :
- 12
- Issue :
- 7 Pt 1
- Database :
- MEDLINE
- Journal :
- JACC. Cardiovascular imaging
- Publication Type :
- Academic Journal
- Accession number :
- 30121266
- Full Text :
- https://doi.org/10.1016/j.jcmg.2018.06.016