Abstract
Background: Non-ischemic idiopathic dilated cardiomyopathy (DCM) patients with scar on Late Gadolinium Enhancement (LGE) cardiac MR (CMR) are at higher risk of developing VT or VF. However, many patients with no scar on LGE still experience VT/VF. CMR feature tracking (CMR-FT) allows quantification of mechanics by evaluating myocardial fiber deformation. We sought to investigate if mechanical deformation measured by CMR-FT differs in DCM patients with/without VT/VF.
Methods: In a retrospective study, we identified DCM patients referred for CMR viability assessment. Patients were divided into two groups based on the history of documented VT/VF prior to CMR. Global longitudinal (GLS), circumferential (GCS) and radial (GRS) strains were measured (CVI42). The presence and extent of scar were evaluated using the threshold of 5 SD.
Results: A total of 354 patients were included. 77 (22%) patients had documented VT/VF and 277 had no history of VT/VF. There were no differences in the extent of LGE between the two groups (Table), however there were significant differences between global strains among the two groups (Table). No correlations were found between global strain values and the presence or extent of scar in the whole cohort, either in +VT/VF or -VT/VF groups.
Conclusion: Myocardial deformation measured using CMR-FT differs between DCM patients referred for CMR with/without VT/VF. This preliminary study suggests potential role of strain imaging for risk stratification in DCM patients.