MRI Feature Tracking Strain in Pulmonary Hypertension: Utility of Combined Left Atrial Volumetric and Deformation Assessment in Distinguishing Post- From Pre-capillary Physiology

Kai'En Leong; Luke Howard; Francesco Lo Giudice; Holly Pavey; Rachel Davies; Gulammehdi Haji; Simon Gibbs; Deepa Gopalan

doi:10.3389/fcvm.2022.787656

MRI Feature Tracking Strain in Pulmonary Hypertension: Utility of Combined Left Atrial Volumetric and Deformation Assessment in Distinguishing Post- From Pre-capillary Physiology

Front Cardiovasc Med. 2022 Mar 17:9:787656. doi: 10.3389/fcvm.2022.787656. eCollection 2022.

Authors

Kai'En Leong^{1

2}, Luke Howard^{3

4}, Francesco Lo Giudice^{3

5}, Holly Pavey⁶, Rachel Davies³, Gulammehdi Haji³, Simon Gibbs⁴, Deepa Gopalan^{1

7}

Affiliations

¹ Department of Radiology, Imperial College National Health Service Trust/Hammersmith Hospital, London, United Kingdom.
² Department of Cardiology, The Royal Melbourne Hospital, Parkville, VIC, Australia.
³ National Pulmonary Hypertension Service, Imperial College National Health Service Trust, London, United Kingdom.
⁴ National Heart and Lung Institute, Imperial College London, London, United Kingdom.
⁵ Department of Cardiology, Imperial College National Health Service Trust/Hammersmith Hospital, London, United Kingdom.
⁶ Division of Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom.
⁷ Department of Radiology, Cambridge University Hospitals National Health Service Trust, Cambridge, United Kingdom.

Abstract

Aims: Pulmonary hypertension (PH) is dichotomized into pre- and post-capillary physiology by invasive catheterization. Imaging, particularly strain assessment, may aid in classification and be helpful with ambiguous hemodynamics. We sought to define cardiac MRI (CMR) feature tracking biatrial peak reservoir and biventricular peak systolic strain in pre- and post-capillary PH and examine the performance of peak left atrial strain in distinguishing the 2 groups compared to TTE.

Methods and results: Retrospective cross-sectional study from 1 Jan 2015 to 31 Dec 2020; 48 patients (22 pre- and 26 post-capillary) were included with contemporaneous TTE, CMR and catheterization. Mean pulmonary artery pressures were higher in the pre-capillary cohort (55 ± 14 vs. 42 ± 9 mmHg; p < 0.001) as was pulmonary vascular resistance (median 11.7 vs. 3.7 WU; p < 0.001). Post-capillary patients had significantly larger left atria (60 ± 22 vs. 25 ± 9 ml/m²; p < 0.001). There was no difference in right atrial volumes between groups (60 ± 21 vs. 61 ± 29 ml/m²; p = 0.694), however peak RA strain was lower in post-capillary PH patients (8.9 ± 5.5 vs. 18.8 ± 7.0%; p < 0.001). In the post-capillary group, there was commensurately severe peak strain impairment in both atria (LA strain 9.0 ± 5.8%, RA strain 8.9 ± 5.5%). CMR LAVi and peak LA strain had a multivariate AUC of 0.98 (95% CI 0.89-1.00; p < 0.001) for post-capillary PH diagnosis which was superior to TTE.

Conclusion: CMR volumetric and deformation assessment of the left atrium can highly accurately distinguish post- from pre-capillary PH.

Keywords: cardiac MRI (CMR); feature tracking (CMR-FT); left atrial strain (LA strain); post-capillary pulmonary hypertension; pre-capillary pulmonary hypertension; pulmonary hypertension.