Absolute myocardial mass difference and ventriculo-arterial coupling in morphologically defined left ventricular...

BackgroundLeft ventricular non-compaction (LVNC) is increasingly recognized as a morphological phenotype rather than a distinct cardiomyopathy. Current cardiovascular magnetic resonance (CMR) criteria rely predominantly on static morphologic thresholds and may not adequately reflect dynamic myocardial adaptation.PurposeTo investigate whether absolute myocardial mass difference (AD) represents a marker of structural-functional remodeling and to assess its relationship with hemodynamic and flow-related parameters in morphologically defined LVNC.Material and MethodsIn this retrospective study, 99 patients fulfilling Petersen and Grothoff CMR criteria for LVNC and 66 frequency-matched controls underwent multiparametric 1.5-T CMR. Volumetric indices, left atrial volume, cine-derived functional parameters, and aortic phase-contrast MRI flow timing indices, including time-to-peak velocity (TPV), ejection time (ET), and TPV/ET ratio, were analyzed. AD was defined as the indexed difference between end-diastolic myocardial mass and cycle-averaged myocardial mass. Between-group comparisons, effect size analysis, correlation testing, and ROC analysis were performed.ResultsAD was significantly higher in LVNC patients than in controls (3.71 ± 2.43 vs. 2.03 ± 1.49 g/m²; P < 0.001) and demonstrated a large effect size (Cohen's d = 0.81). LVNC patients exhibited increased end-diastolic and end-systolic volume indices (both P < 0.001), preserved cardiac index, and altered systolic flow timing characteristics. AD correlated positively with left atrial volume (r = 0.39; P < 0.001) and cardiac index (r = 0.27; P = 0.007), whereas no significant association was observed with TPV/ET. ROC analysis demonstrated modest discriminatory performance (AUC = 0.71).ConclusionIn morphologically defined LVNC, AD is increased and associated with atrial remodeling and preserved hemodynamic adaptation. These findings suggest that AD may represent a marker of dynamic structural-functional remodeling rather than static trabecular excess. Incorporation of AD into multiparametric CMR assessment may improve phenotypic characterization and help distinguish compensated hypertrabecularization from clinically relevant myocardial disease.