Reversible left ventricular trabecular remodeling after bariatric surgery in obesity: a prospective cohort study using quantitative cardiac MRI.

BACKGROUND

Obesity is associated with structural and functional cardiac remodeling; however, its quantitative imaging characteristics and the role of left ventricular trabeculation remain incompletely understood. This study aimed to characterize left ventricular trabeculation using multi-parametric cardiac magnetic resonance in patients with obesity, explore its association with subclinical cardiac dysfunction, and evaluate longitudinal changes following bariatric surgery.

METHODS

In this prospective single-center study, 30 patients with severe obesity underwent cardiac magnetic resonance imaging before and approximately 12 months after bariatric surgery, along with 30 age- and sex-matched healthy controls. Quantitative parameters included the non-compacted to compacted layer ratio (NC/C), trabecular mass fraction, left ventricular mass, left ventricular ejection fraction, global longitudinal strain, and diastolic filling indices. Left ventricular ejection fraction indexed to body surface area was analyzed as an exploratory parameter. Mediation analysis was performed to assess whether trabeculation statistically explained part of the association between body mass index and cardiac function, adjusting for age, sex, and blood pressure.

RESULTS

Compared with controls, patients with obesity showed significantly higher NC/C (1.68±0.24 vs. 1.11±0.19, P<0.001) and lower left ventricular ejection fraction (57.87%±6.22% vs. 63.40%±6.94%, P<0.05). In mediation analysis, the total effect of body mass index on left ventricular ejection fraction was -0.29 [95% confidence interval (CI): -0.56 to -0.02]. The indirect effect via the NC/C was statistically significant (β=-0.46, 95% CI: -0.81 to -0.09), while the direct effect was not significant (β=0.17, 95% CI: -0.25 to 0.59). Following bariatric surgery, trabeculation and left ventricular mass decreased significantly, while left ventricular ejection fraction, global longitudinal strain, and diastolic filling indices improved (P<0.05).

CONCLUSIONS

Quantitative cardiac magnetic resonance analysis demonstrates increased left ventricular trabeculation in obesity, which decreases following weight reduction. Trabeculation is associated with subclinical cardiac dysfunction and may contribute to the association between obesity and impaired cardiac function. These findings suggest that trabecular remodeling in obesity represents a dynamic imaging phenotype, although further studies are required to clarify underlying mechanisms.