Biomechanical and Metabolic Profiling of the Liver for Cardiometabolic Risk Stratification Using 3D Magnetic Resonance Elastography

Background:
Coronary heart disease (CHD) is frequently associated with metabolic comorbidities, including visceral obesity, insulin resistance, and hepatic steatosis. While body composition metrics such as visceral adipose tissue (VAT), subcutaneous fat, and hepatic lipid accumulation are established risk markers, the integration of hepatic biomechanics may refine stratification of at-risk patients. This study explores the role of multiparametric three-dimensional (3D) magnetic resonance elastography (MRE) in conjunction with body composition profiling to assess liver tissue mechanics and their association with CHD severity.

Methods:
In this prospective cohort of 193 patients with varying degrees of hepatic and cardiovascular health, liver biomechanics were assessed using 3D MRE at 60 Hz. Quantitative metrics—including storage modulus, loss modulus, damping ratio (ξ), wave attenuation (α), and phase angle (Y)—were extracted and correlated with markers of body composition (proton density fat fraction [PDFF], VAT, and body mass index [BMI]) and CHD risk (Framingham risk score, coronary artery calcium [CAC] score). Spearman’s correlation and multivariate regression analyses were performed.

Results:
A distinct subset of patients exhibited a 'biomechanical risk phenotype', characterized by reduced phase angle (Y) and wave attenuation (α), which correlated with increased VAT (r = 0.62, p < 0.001), elevated PDFF (r = 0.58, p < 0.001), and intermediate FIB-4 scores (1.3–3.5). These patients were more likely to present with low-grade systemic inflammation (CRP >3 mg/L), elevated liver enzymes (ASAT >40 U/L), and subclinical coronary calcification (CAC score 1–100). Notably, these biomechanical changes occurred in the absence of increased liver stiffness, suggesting a pre-fibrotic, pro-inflammatory state. This phenotype was overrepresented among individuals with metabolic syndrome and early CHD features but lacked overt fibrosis or cirrhosis.

Conclusion:
3D MRE-derived biomechanical parameters, when integrated with body composition profiling, identify a pre-fibrotic hepatic state linked to metabolic dysfunction and subclinical CHD. This biomechanical-body composition axis offers a novel, noninvasive tool for early risk stratification in patients at the intersection of cardiometabolic and hepatic disease, potentially guiding preventive interventions before irreversible damage occurs.