Association of residential green space, blue space, and natural environment with the incident heart failure and cardiac morpho-functional phenotypes: a UK biobank-based prospective cohort and imaging study

AIMS: Environmental exposures are increasingly recognized as modifiable risk factors for heart failure (HF), yet the roles of residential green space, blue space, and natural environments in cardiac structural/functional remodelling and HF development remain underexplored. We aimed to prospectively evaluate associations between residential green space, blue space, and natural environment exposure with incident HF and cardiac morpho-functional phenotypes. METHODS AND RESULTS: We analyzed 437 429 UK Biobank participants free of baseline HF, who were enrolled between 2006 and 2010. Residential green space, blue space, and natural environment were quantified as land coverage percentages within 300-m and 1000-m buffers. Incident HF was ascertained via linked health records. Cox proportional regression models adjusted for sociodemographic, lifestyle, clinical, polygenic risk score, and air pollution covariates assessed HF risk. Cardiac magnetic resonance (CMR) imaging data from the UK Biobank data was analyzed for associations with ventricular/atrial structure and function. During the median follow-up duration of 13.9 (IQR: 13.1, 14.5) years, 16 564 incident HF cases were identified. Within a 1000-m buffer, higher exposure to green space (HR 0.87, 95% CI 0.82-0.92), blue space (HR 0.77, 95% CI 0.75-0.80), and natural environment (HR 0.85, 95% CI 0.80-0.90) (for 3rd vs. 1st tertile) was consistently associated with a reduced risk of HF. Similar trends were observed for the 300-m buffer, with comparable protective associations for green space, blue space, and natural environment. In CMR analyses, higher green space exposure correlated with reduced odds of concentric remodelling (OR 0.72, 95% CI 0.54-0.96), eccentric hypertrophy (OR 0.66, 95% CI 0.55-0.79), and concentric hypertrophy (OR 0.29, 95% CI 0.13-0.63) within 1000-m buffers. For blue space (within the 1000-m buffer), higher exposure showed a reduced odds of (OR 0.73, 95% CI 0.59-0.90) and concentric hypertrophy (OR 0.43, 95% CI, 0.25-0.76). Natural environment exposure within a 1000-m buffer demonstrated attenuation of adverse remodelling comparable to green space effects. CONCLUSION: Residential exposure to green space, blue space, and natural environments is associated with lower HF incidence and healthier cardiac phenotypes, independent of genetic predisposition and air pollution. Green space demonstrates the most robust cardioprotective effects.