Volume 18 Supplement 1

19th Annual SCMR Scientific Sessions

Open Access

Native left ventricular myocardial T1 spatial heterogeneity in non-ischemic dilated cardiomyopathy

  • Abyaad Kashem1,
  • Ravi V Shah1,
  • Shingo Kato1,
  • Steven Bellm1,
  • Sébastien Roujol1,
  • Tamer Basha1,
  • Jihye Jang1,
  • Warren J Manning1, 2 and
  • Reza Nezafat2
Journal of Cardiovascular Magnetic Resonance201618(Suppl 1):Q41

https://doi.org/10.1186/1532-429X-18-S1-Q41

Published: 27 January 2016

Background

Myocardial fibrosis is involved in the pathology of non-ischemic dilated cardiomyopathy (NICM). Recently, the application of native (non-contrast) myocardial T1 measurement has been proposed as an imaging biomarker of cardiac remodeling. However, spatial heterogeneity in T1 measurements has been observed across different segments and slices. Furthermore, T1 values measured with current T1 mapping sequences are influenced by myocardial T2 values. The objective of this study was to 1) assess the spatial heterogeneity of T1 measurements across different segments and slices in healthy subjects and patients, and 2) determine the association of native T1 with myocardial structure and function.

Methods

We prospectively studied 39 NICM patients (LVEF≤50% without evidence of prior infarction by CMR) and 30 subjects with normal LV systolic function without known cardiovascular disease. CMR was performed using a 1.5-T MRI scanner (Philips Achieva). Native T1 mapping was performed using slice-interleaved T1 mapping sequence (STONE) [1]. T2 mapping was performed using slice-interleaved T2 mapping [2]. Voxel-wise T1 and T2 were estimated using a 2-parameter and 3-parameter model [3]. All images were corrected for motion [4]. T1, T2, and extra-cellular volume (ECV) measurements were measured using a 16 segments AHA model across the base, mid, and apical LV.

Results

NICM participants (57 ± 15 years) were predominantly male (74%). By design, all had a reduced LV ejection fraction (mean LVEF 34 ± 10%). Figure 1 shows native T1, T2, and ECV in two patients with a NICM. Parametric maps to the right in each panel demonstrate full ventricular coverage. The regional distribution of native myocardial T1 was similar in patients with and without NICM[RN1], as shown in Figure 2. Relative to subjects without NICM, subjects with NICM had a higher native T1 (1131 ± 51 vs. 1070 ± 28 msec; p < 0.0001), a higher ECV (0.28 ± 0.04 vs. 0.25 ± 0.02, P = 0.001) and a longer myocardial T2 (52 ± 8 vs. 47 ± 5 msec; P = 0.01). After multivariable adjustment, a lower global native T1 time was associated with a higher LVEF (b = -0.59, P = 0.0003), higher right ventricular ejection fraction (b = -0.47, P = 0.006), and lower left atrial volume index (b = 0.51, P = 0.001).
Figure 1

(A) Images from a 47-year-old woman with a NICM with moderate reduction in LV function (LV ejection fraction 30%). (B) Images from a 39-year-old heathy male (LV ejection fraction 61%).

Figure 2

Variability in segmental native T 1 across all 16 myocardial segments in individuals with normal LV function (red) and study participants with NICM (blue). The error bars represent standard error of the mean.

Conclusions

In NICM, native myocardial T1 is elevated in a homogeneous manner, suggesting a global (not regional) abnormality in myocardial tissue composition. This low variability is similar between healthy and NICM patients across different segments. For subjects with NICM, native T1 is associated with biventricular systolic function and left atrial volume, and may represent a non-contrast marker of tissue remodeling in this cohort.

Authors’ Affiliations

(1)
Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center
(2)
Department of Radiology, Beth Israel Deaconess Medical Center

References

  1. Weingartner : MRM. 2015Google Scholar
  2. Basha : MRM. 2015Google Scholar
  3. Akcakaya : MRM. 2015Google Scholar
  4. Roujol : JCMR. 2015Google Scholar

Copyright

© Kashem et al. 2016

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

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