Residential Greenness and Risk of Coronary Artery Disease Following COVID‐19: A Nationwide Cohort Study in South Korea

BACKGROUND: Residential greenness has been associated with lower ischemic heart disease risk in general populations; however, its relevance after SARS-CoV-2 infection is unclear. We evaluated the associations between residential greenness and incident coronary artery disease following COVID-19. METHODS: 30 days after infection. Inverse probability of treatment weighting was used to balance covariates, and weighted Cox models were applied to estimate adjusted hazard ratios (aHRs) with 95% CIs. Analyses were stratified by COVID-19 severity, vaccination status, variant period, sex, age, and income. RESULTS: Among 3 097 179 individuals (61.4% men), 25.3%, 59.7%, and 15.0% were classified as having low, moderate, and high NDVI exposure, respectively. Although NDVI was not associated with risk of acute coronary syndrome, higher NDVI was associated with lower risk of chronic ischemic heart disease (aHR, 0.86 [95% CI, 0.84-0.88] for moderate NDVI; aHR, 0.82 [95% CI, 0.80-0.84] for high NDVI). Associations were stronger in moderate to severe COVID-19, vaccinated individuals, males, and younger individuals. CONCLUSIONS: Residential greenness was not associated with post-COVID acute coronary events but was consistently associated with lower chronic ischemic heart disease risk, suggesting a potential role in long-term cardiovascular health after SARS-CoV-2 infection.