Cardiovascular magnetic resonance based diagnosis of left ventricular non-compaction cardiomyopathy: impact of cine bSSFP strain analysis.

BACKGROUND

Investigation of the myocardial strain characteristics of the left ventricular non-compaction (LVNC) phenotype with cardiovascular magnetic resonance (CMR) feature tracking.

METHODS

CMR cine balanced steady-state free precession data sets of 59 retrospectively identified LVNC phenotype patients (40 years, IQR: 28-50 years; 51% male) and 36 healthy subjects (39 years, IQR: 30-47 years; 44% male) were evaluated for LV volumes, systolic function and mass. Hypertrabeculation in patients and healthy subjects was evaluated against established CMR diagnostic criteria. Global circumferential strain (GCS), global radial strain (GRS) and global longitudinal strain (GLS) were evaluated with feature-tracking software. Subgroup analyses were performed in patients (n = 25) and healthy subjects (n = 34) with normal LV volumetrics, and with healthy subjects (n = 18) meeting at least one LVNC diagnostic criteria.

RESULTS

All LVNC phenotype patients, as well as a significant proportion of healthy subjects, met morphology-based CMR diagnostic criteria: non-compacted (NC): compacted myocardial diameter ratio > 2.3 (100% vs. 19.4%), NC mass > 20% (100% vs. 44.4%) and > 25% (100% vs. 13.9%), and NC mass indexed to body surface area > 15 g/m (100% vs. 41.7%). LVNC phenotype patients demonstrated reduced GRS (26.4% vs. 37.1%; p < 0.001), GCS (- 16.5% vs. -20.5%; p < 0.001) and GLS (- 14.6% vs. -17.1%; p < 0.001) compared to healthy subjects, with statistically significant differences persisting on subgroup comparisons of LVNC phenotype patients with healthy subjects meeting diagnostic criteria. GCS also demonstrated independent and incremental diagnostic value beyond each of the morphology-based CMR diagnostic criteria.

CONCLUSIONS

LVNC phenotype patients demonstrate impaired strain by CMR feature tracking, also present on comparison of subjects with normal LV volumetrics meeting diagnostic criteria. The high proportion of healthy subjects meeting morphology-based CMR diagnostic criteria emphasizes the important potential complementary diagnostic value of strain in differentiating LVNC from physiologic hypertrabeculation.