Differential Risks of Incident Heart Failure Subtypes Associated with PM2.5 Chemical Constituents in China between 2006 and 2021

Despite substantial declines over the past decade, China’s PM2.5 levels remain far above current WHO guidelines. PM2.5 is a recognized non-negligible risk factor for heart failure (HF), as a mixture, but the specific chemical constituents driving risks across HF subtypes remain unclear. Considering the significant heterogeneity in the etiology and pathophysiology among different HF subtypes, we explored the relationship between chemical constituents of PM2.5 and these HF subtypes. Additionally, we identified the most critical toxic constituent in the Kailuan prospective cohort of 101,521 Chinese adults followed from 2006 to 2021. Over a 14.83-year median follow-up, all chemical constituents of PM2.5 were associated with elevated risk across various HF subtypes, with notably stronger effects on early onset compared to late-onset HF. Moreover, black carbon (BC) (40.2%–48.7%) was the main contributor to overall HF, late-onset HF, and HF with reduced ejection fraction (HFrEF) and mildly reduced (HFmrEF), whereas NH4+ (28.2%) and BC (28.1%) primarily drove early onset HF, and OM (34.8%) was the key constituent for HFpEF. Chronic exposure to specific-constituents of PM2.5 increases various HF subtypes risk, underscoring the importance for regional and constituent-specific regulations to alleviate HF burden.