Abstract
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.