Relationship between left ventricular sphericity and trabeculation indexes in patients with dilated cardiomyopathy: a cardiac magnetic resonance study

Aims: To study the relationship between left ventricular (LV) trabeculations, volume, and sphericity in patients with dilated cardiomyopathy (DCM) by cardiac magnetic resonance imaging (CMR).

Methods and results: Eighty-two patients with DCM were prospectively explored by CMR. The segmental trabeculation index (STI) was defined by the ratio of trabeculated layer thickness on compacted layer thickness per segment. The global trabeculation index (GTI) was defined by the ratio of the sum of the total trabeculated layer thickness to the sum of the total compacted layer thickness. The apex was excluded from the analysis. The mean number of segments with trabeculation per patient was 10 ± 2 with a mean GTI of 0.68 ± 0.32. The LV sphericity index was inversely correlated with LV ejection fraction (R = -0.42, P = 0.0002) and positively with the brain natriuretic peptide (BNP) level (R = 0.34, P = 0.003). The maximal STI was positively correlated with the indexed LV end-diastolic volume (R = 0.32, P = 0.004) and the LV sphericity index (R = 0.25, P = 0.02), but not with the BNP level or LV ejection fraction. The GTI was positively correlated with the LV sphericity index (R = 0.27, P = 0.016) but not with indexed LV end-diastolic volume, BNP levels, or LV ejection fraction.

Conclusion: Trabeculation indexes depend on LV shape and are positively correlated with LV sphericity. These results encourage interpreting LV trabeculation with caution in patients with DCM, considering additional morphologic criteria such as LV geometry.