1354755 - Characterization of 3D Feature Tracking (FT) Strain parameters in patients with ‘real world’ CMR diagnosis of left ventricular non-compaction cardiomyopathy

Left ventricular non-compaction cardiomyopathy (LVNC) is characterized by the presence of a bi-layered myocardium with >2-fold ratio of non-compacted:compacted myocardium. The natural history of LVNC is heterogenous, however reduced LV systolic function (LVEF) has been identified as an important predictor of poor outcomes (1), and therefore further sub-characterization of LV dysfunction may have significance in identifying patients at risk long-term. 3D-FT strain characteristics are yet to be reported in LVNC patients. The aim of this study therefore was to evaluate 3D-FT strain parameters in LVNC patients, and explore their association with LVEF, LV volume and LV mass.

Methods:

IRB approval was obtained for this retrospective study. A data search was performed for patients who received a CMR diagnosis of LVNC from Jan 2010 to Aug 2022. All LVNC patients met criteria for CMR diagnosis (2) reported by an attending radiologist. Age- and gender-matched normal CMR studies were identified as control studies. Cine balanced SSFP data sets were evaluated for LVEF, indexed LV end-diastolic volume (LVEDVi) and  myocardial mass (MASSi). 3D global radial, circumferential and longitudinal peak strain (GRS, GCS and GLS, respectively) were evaluated with automated 3D-FT strain post-processing software (CVI⁴², Circle Cardiovascular Imaging, V5.13). Statistical analysis were performed using IBM SPSS Statistics (V25.0). Normal distribution was confirmed using the Shapiro-Wilk test, and variables compared with independent samples t-test. Subgroup analysis was performed to determine if differences in 3D-FT strain persisted independent of abnormal LVEF, increased LVEDVi or increased MASSi. Pearson’s Correlation was determined for 3D-FT and LVEF, LVEDVi and MASSi. P-values less than 0.05 were considered to be statistically significant.

Results:

13 patients with a CMR diagnosis of LVNC with 13 age- and gender-matched normal studies were identified (median age 55 years, IQR 49-69, 77% male). LVNC patients demonstrated reduced 3D-GRS, GCS and GLS strain parameters vs controls: 3D-GRS (32 ± 6% vs 16 ± 10%, P<0.01), 3D-GCS (-18 ± 2% vs -11 ± 6%, P< 0.005) and 3D-GLS (-14 ± 2% vs -9 ± 4%, P< 0.01). In patients with LVEF >50% or normal LVEDVi (3), no significant differences in 3D-FT strain were detected between LVNC patients and controls. For patients with normal MASSi (3), 3D-GCS and GLS planes remained significantly reduced in LVNC patients, however there were no significant differences in 3D-GRS (table 1). 3D-FT reduction highly correlated with reduced LVEF and increased LVEDVi, but not increased MASSi (table 2).

Conclusion:

3D-FT global strain was significantly reduced in all planes in patients who received a CMR diagnosis of LVNC when compared with controls. 3D-GCS and GLS differences persisted in patients with normal MASSi. Differences did not persist in subgroups with preserved LVEF >50% or normal LVEDVi. Further studies are required to sub-categorise 3D-FT strain myocardial dysfunction in LVNC.