Abstract / Summary
Abstract Background Metabolic and inflammatory dysregulation have been implicated in the phenotypic heterogeneity of hypertrophic cardiomyopathy (HCM). A recent study demonstrated that the triglyceride-glucose (TyG) index is independently associated with left ventricular outflow tract (LVOT) obstruction in HCM using echocardiography, but the relationship between metabolic and inflammatory biomarkers and cardiac magnetic resonance (CMR)-derived measures of structural severity and myocardial fibrosis remains unexplored. We aimed to investigate associations between metabolic (atherogenic index of plasma [AIP], TyG index) and inflammatory (neutrophil-to-lymphocyte ratio [NLR], platelet-to-lymphocyte ratio [PLR], systemic immune-inflammation index [SII]) biomarkers, individually and as composite profile scores, and CMR-derived structural and functional severity in patients with HCM. Methods In this single-center, retrospective, cross-sectional analytic study, 63 patients with HCM who underwent CMR were included. A metabolic profile score (z-AIP + z-TyG) and an inflammatory profile score (z-PLR + z-SII) were constructed following collinearity assessment. Associations with LVOT obstruction and late gadolinium enhancement (LGE) extent ≥ 5% were assessed using multivariable logistic regression adjusted for age, sex, hypertension, diabetes mellitus, and dyslipidemia, and receiver operating characteristic (ROC) analysis. Results LVOT obstruction was present in 27 patients (42.9%), and LGE ≥ 5% in 46 (73.0%). AIP, the TyG index, and the metabolic profile score were significantly higher in patients with LVOT obstruction (all P < 0.001). The metabolic profile score remained independently associated with both LVOT obstruction (OR 3.07, 95% CI 1.57–6.01, P = 0.001) and LGE ≥ 5% (OR 1.50, 95% CI 1.04–2.15, P = 0.030) after adjustment, with good discriminatory performance (AUC 0.864 and 0.780, respectively); exploratory analyses indicated that AIP was the principal driver of this performance, with a limited independent contribution from TyG, particularly for LVOT obstruction. No inflammatory marker, individually or as a composite score, was associated with any measure of structural or functional severity. Conclusions A composite metabolic profile score combining AIP and the TyG index was independently associated with both LVOT obstruction and myocardial fibrosis burden on CMR in patients with HCM, extending prior echocardiography-based findings, although AIP appeared to be the main contributor to this association. Hematological inflammatory indices showed no comparable association. These hypothesis-generating findings warrant prospective, multicenter validation.