Left ventricular hypertrabeculation - an unanswered question

Abstract

Abstract Funding Acknowledgements Type of funding sources: Other. Main funding source(s): Supported by the ÚNKP-19-3-II New National Excellence Program of the Ministry for Innovation and Technology Left ventricular (LV) hypertrabeculation (H-TRAB) is a morphological description when the LV is highly trabeculated, but it remains below the diagnostic criterion of noncompaction cardiomyopathy (NCMP). Although, it is a frequent finding on cardiac MRI scans its diagnostic and prognostic relevance remains controversial. In this cardiac MRI study, we aimed to describe the LV functional and feature-tracking strain values of healthy subjects with LV H-TRAB to decide whether it is a normal variant or an NCMP-like pattern. We included 189 adult participants with good LV ejection fraction (EF), and without co-morbidities. 63 of them had a morphology of LV H-TRAB (H-TRAB, age: 37.1 ± 14.4 years; EF: 66.4 ± 5.1%), 63 patients were diagnosed with NCMP (age: 36.3 ± 14.0 years, EF: 65.8 ± 5.5%) and the remaining 63 people were healthy controls (38.3 ± 14.0 years, EF: 69.0 ± 4.9%). MR examinations were performed with 1,5T Philips Achieva and Siemens Aera devices. The Medis Suite software was used for post-processing analysis, the MedCalc software for statistics, p < 0.05 was considered statistically significant. No significant differences were found between the functional parameters of the H-TRAB and NCMP groups. However, the EF was decreased, the end-diastolic (EDVi), and end-systolic volume (ESVi), the myocardial mass (LV-massi), and trabeculated muscle mass (LV-trabi) values were increased in both groups compared to controls (H-TRAB vs. control: EF: 6.4 ± 5.4 vs. 69.0 ± 5.0%, EDVi: 74.4 ± 14.3 vs. 69.7 ± 12.8 ml/m2, ESVi: 25.1 ± 6.7 vs. 21.7 ± 5.8 ml/m2, LV-massi: 77.0 ± 15.1 vs. 71.2 ± 12.3 g/m2, LV-trabi: 25.0 ± 5.1 vs. 20.1 ± 4.0 g/m2; NCMP vs. control: EF: 65.8 ± 5.5 vs. 69.0 ± 5.0%, EDVi: 77.8 ± 15.0 vs. 69.7 ± 12.8 ml/m2, ESVi: 26.7 ± 7.9 vs. 21.7 ± 5.8 ml/m2, LV-massi: 76.8 ± 18.0 vs. 71.2 ± 12.3 g/m2, LV-trabi: 25.9 ± 7.5 vs. 20.1 ± 4.0 g/m2; p ≤ 0.05). The global circumferential strain (GCS) differed significantly between these groups: its absolute value was the lowest in the NCMP and the highest in the control group (NCMP vs. H-TRAB vs. control: -30.2% vs. -34.3% vs. -35.9%; p < 0.05). Similar results were found in the comparison of the mean segmental circumferential strain values of the apical-, mid- and basal-parts between the three groups. The absolute values of these parameters were the lowest in the NCMP patients, followed by the H-TRAB, and were the highest in the control group. These results suggest that the LV functional and strain values of the H-TRAB population are more similar to NCMP patients than healthy controls. Further studies are necessary to determine the pathological implications and consequences of this morphology.