Preliminary Study of Dilated Cardiomyopathy at a High Altitude Based on Cardiac Magnetic Resonance Feature Tracking

Objective To investigate the application of cardiovascular magnetic resonance feature tracking (CMR-FT) in assessing myocardial strain in dilated cardiomyopathy (DCM) patients residing at high altitudes.

Methods We retrospectively enrolled 29 DCM patients living at high altitudes (DCM-H), 27 DCM patients living in a low-altitude plain environment (DCM-P), 23 healthy volunteers living at a high altitude (HV-H), and 24 healthy volunteers living in a low-altitude plain environment (HV-P). All subjects underwent cine MRI scanning using a 3.0T rapid steady-state free precession sequence. The CMR images thus acquired were analyzed using cvi42, a post-processing software, to obtain left ventricular function and myocardial strain parameters.

Results Compared with the HV-H group, the DCM-H group showed higher left ventricle end-diastolic volume (LVEDV) and left ventricle end-systolic volume (LVESV), and lower left ventricular ejection fraction (LVEF) and stroke volume ( LVSV) (all P < 0.01). No significant difference was observed in cardiac function between the DCM-H and DCM-P groups (all P > 0.05). The absolute values of global radial strain (GRS), global circumferential strain (GCS), and global longitudinal strain (GLS) in the DCM-H group were lower than those in the HV-P group (14.5 ± 6.5% vs. 34.2 ± 10.7%, －11.1 ± 4.4% vs. －19.9 ± 2.8%, and －7.7 ± 3.2% vs. －13.6 ± 4.1%, respectively), with the differences being statistically significant (all P < 0.001). The DCM-H group had higher absolute GRS, GCS, and GCS values than the DCM-P group did (14.5 ± 6.5% vs. 7.0 ± 2.7%, －11.1 ± 4.4% vs. －5.4 ± 2.2%, and －7.7 ± 3.2% vs. －4.3 ± 1.7%, respectivley, all P < 0.01).

Conclusion Myocardial strain in DCM patients living at a high altitude is lower than that in healthy volunteers living at a high altitude, but higher than that in DCM patients living in a low-altitude plain environment. CMR-FT can be used to quantitatively assess myocardial contractility in DCM patients living at a high altitude, showing promise for clinical application.