Probing Evidence of Cerebral White Matter Microstructural Disruptions in Ischemic Heart Disease Before and Following Cardiac Rehabilitation: A Diffusion Tensor MR Imaging Study

Stefan E Poirier; Neville G Suskin; Alexander V Khaw; Jonathan D Thiessen; Joel K Shoemaker; Udunna C Anazodo

doi:10.1002/jmri.28964

Probing Evidence of Cerebral White Matter Microstructural Disruptions in Ischemic Heart Disease Before and Following Cardiac Rehabilitation: A Diffusion Tensor MR Imaging Study

J Magn Reson Imaging. 2023 Aug 17. doi: 10.1002/jmri.28964. Online ahead of print.

Authors

Stefan E Poirier^{1

2}, Neville G Suskin³, Alexander V Khaw⁴, Jonathan D Thiessen^{1

2

5}, Joel K Shoemaker⁶, Udunna C Anazodo^{1

2

4

7

8}

Affiliations

¹ Lawson Imaging, Lawson Health Research Institute, London, Ontario, Canada.
² Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.
³ Division of Cardiology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.
⁴ Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.
⁵ Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.
⁶ School of Kinesiology, Western University, London, Ontario, Canada.
⁷ Research Centre for Studies in Aging, McGill University, Montréal, Québec, Canada.
⁸ Department of Neurology and Neurosurgery, McGill University, Montréal, Québec, Canada.

PMID: 37589418
DOI: 10.1002/jmri.28964

Abstract

Background: Ischemic heart disease (IHD) is linked to brain white matter (WM) breakdown but how age or disease effects WM integrity, and whether it is reversible using cardiac rehabilitation (CR), remains unclear.

Purpose: To assess the effects of brain aging, cardiovascular disease, and CR on WM microstructure in brains of IHD patients following a cardiac event.

Study type: Retrospective.

Population: Thirty-five IHD patients (9 females; mean age = 59 ± 8 years), 21 age-matched healthy controls (10 females; mean age = 59 ± 8 years), and 25 younger controls (14 females; mean age = 26 ± 4 years).

Field strength/sequence: 3 T diffusion-weighted imaging with single-shot echo planar imaging acquired at 3 months and 9 months post-cardiac event.

Assessment: Tract-based spatial statistics (TBSS) and tractometry were used to compare fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) in cerebral WM between: 1) older and younger controls to distinguish age-related from disease-related WM changes; 2) IHD patients at baseline (pre-CR) and age-matched controls to investigate if cardiovascular disease exacerbates age-related WM changes; and 3) IHD patients pre-CR and post-CR to investigate the neuroplastic effect of CR on WM microstructure.

Statistical tests: Two-sample unpaired t-test (age: older vs. younger controls; IHD: IHD pre-CR vs. age-matched controls). One-sample paired t-test (CR: IHD pre- vs. post-CR). Statistical threshold: P < 0.05 (FWE-corrected).

Results: TBSS and tractometry revealed widespread WM changes in older controls compared to younger controls while WM clusters of decreased FA in the fornix and increased MD in body of corpus callosum were observed in IHD patients pre-CR compared to age-matched controls. Robust WM improvements (increased FA, increased AD) were observed in IHD patients post-CR.

Data conclusion: In IHD, both brain aging and cardiovascular disease may contribute to WM disruptions. IHD-related WM disruptions may be favorably modified by CR.

Level of evidence: 3 TECHNICAL EFFICACY: Stage 2.

Keywords: cardiac rehabilitation; diffusion tensor imaging; ischemic heart disease; tract-based spatial statistics; tractometry; white matter.

Abstract

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