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Longitudinal changes in myocardial T 1 and T 2 relaxation times related to diffuse myocardial fibrosis in aortic stenosis; before and after aortic valve replacement
Author(s) -
Kvernby Sofia,
Rönnerfalk Mattias,
Warntjes Marcel,
Carlhäll CarlJohan,
Nylander Eva,
Engvall Jan,
Tamás Éva,
Ebbers Tino
Publication year - 2018
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.25980
Subject(s) - medicine , aortic valve replacement , myocardial fibrosis , stenosis , fibrosis , cardiology , aortic valve , aortic valve stenosis , prospective cohort study , biomarker , radiology , biochemistry , chemistry
Background Diffuse myocardial fibrosis is associated with adverse outcomes, although detection and quantification is challenging. Cardiac MR relaxation times mapping represents a promising imaging biomarker for diffuse myocardial fibrosis. Purpose To investigate whether relaxation times can detect longitudinal changes in myocardial tissue composition associated with diffuse fibrosis in patients with severe aortic stenosis (AS) before and after aortic valve replacement (AVR). Study type Prospective longitudinal study. Population/Subjects/Phantom/Specimen/Animal Model Fifteen patients with severe AS. Field Strength/Sequence 3T / 3(3)3(3)5‐MOLLI, T 2 ‐GraSE, and 3D‐QALAS. Assessment Patients underwent MR examinations at three timepoints: before AVR, as well as 3 and 12 months after AVR. Data from each patient was analyzed in 16 myocardial segments. Statistical Tests The segment‐wise T 1 and T 2 data were analyzed over time after surgery using linear mixed models for repeated measures analysis. Results The results showed that T 1 relaxation times were significantly ( P < 0.05) shorter 3 and 12 months postoperative than preoperative and that the T 2 relaxation times were significantly ( P < 0.05) longer 3 and 12 months postoperative than preoperative for both 3D and 2D mapping methods. No significant changes were seen between 3 and 12 months postoperative for any of the methods ( P = 0.06/0.19 for T 1 with 3D‐QALAS/MOLLI and P = 0.09/0.25 for T 2 with 3D‐QALAS/GraSE). Data Conclusion We demonstrated that changes in myocardial relaxation times and thus tissue characteristics can be observed within 3 months after AVR surgery. The significant changes in relaxation times from preoperative examinations to the follow‐up may be interpreted as a reduction of interstitial fibrosis in the left ventricular wall. Level of Evidence: 1 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018;48:799–807.