In a 16-year prospective follow-up of 6,785 multi-ethnic adults (MESA cohort, 2000–2002), four baseline biomarkers — IL-6, D-dimer, CRP, and fibrinogen — each independently predicted incident heart failure (485 events). Hazard ratios per 1-SD increment ranged from 1.13 (fibrinogen) to 1.20 (IL-6). A composite inflammatory burden index explained 53.7% of variance across biomarkers and carried an HR of 1.25. Crucially, sequential biomarker adjustment reduced the Black-White log-hazard difference by 57.5%, and no race-by-biomarker interaction was detected, suggesting uniform biological susceptibility across groups but unequal structural exposure driving higher inflammatory load.
These findings matter because they reframe a persistent public-health puzzle. Rather than biology differing between racial groups, the data point toward differential structural exposures — neighbourhood pollution, chronic stress, socioeconomic adversity — elevating inflammatory burden disproportionately in Black adults, who then bear excess heart failure risk. This mechanistic pathway is, in principle, modifiable. The robustness to PM2.5 and NO2 co-adjustment is reassuring but does not eliminate unmeasured confounding from other environmental or social stressors. The 57.5% mediation estimate is striking but, as the authors acknowledge, not proof of causality from observational data. As a preprint not yet peer-reviewed, effect sizes and interpretations may shift after scrutiny. Still, this is more than incremental: it quantifies a plausible, actionable pathway — reducing systemic inflammation — as a potential equity lever in cardiovascular prevention.