The Role of Interleukin-6 in Predicting Adverse Cardiac Outcomes in Asian Hypertrophic Cardiomyopathy

BackgroundInterleukin-6 (IL-6) is a pro-inflammatory cytokine implicated in adverse cardiac remodeling and outcomes in various cardiovascular diseases. Its role in hypertrophic cardiomyopathy (HCM), particularly in risk stratification and prognosis, remains underexplored. This study evaluates serum IL-6 levels alongside cardiac magnetic resonance (CMR) imaging parameters as predictors of major adverse cardiac events (MACE) in patients with apical HCM (ApHCM) and non-apical HCM (Non-ApHCM). MethodA cohort of 255 patients was recruited between 2013 and 2023, with blood samples collected for genetic analysis and biomarker testing. A subset of 196 patients underwent CMR imaging to assess left ventricular morphology, function, and myocardial fibrosis. MACE was defined as the composite occurrence of ventricular arrhythmias, heart failure, atrial fibrillation, stroke, or all-cause mortality. ResultsPatients with elevated IL-6 levels (above the median) demonstrated significantly higher MACE rates compared to those with lower levels (7.5 vs. 3.3 events/100 patient-years; pairwise log-rank P < 0.001). IL-6 levels correlated with adverse CMR markers, including myocardial fibrosis, increased left atrial volume, and impaired strain, regardless of HCM subtype. Combining IL-6 levels with morphological classification revealed stepwise risk stratification, with MACE rates escalating from 0.9 (ApHCM with low IL-6) to 8.8 events/100 patient-years (Non-ApHCM with high IL-6) (pairwise log-rank P < 0.001). ConclusionThis study highlights IL-6 as a critical biomarker associated with adverse outcomes in HCM. When integrated with morphological assessment, IL-6 enhances risk stratification and provides a novel approach to assessing disease severity. These findings underscore the potential for IL-6 to guide clinical decision-making and inform therapeutic strategies in HCM.