Introduction and objectives: Previous studies have reported an inverse association between the extent of green space and the risk of cardiovascular disease (CVD). However, longitudinal research focusing on individuals residing within the same geographic area remains scarce. Moreover, comprehensive investigations evaluating the impact of urban green space (UGS) on both CVD incidence and cardiovascular mortality are limited.

Methods: This retrospective cohort study used data from the National Health Insurance Service National Sample Cohort. We included 74 925 individuals aged ≥ 20 years residing in 7 metropolitan cities in South Korea, who maintained consistent residential addresses throughout the study period. UGS exposure was quantified as the area of UGS per 1000 residents in 2010. Participants were followed up from January 1, 2011 to December 31, 2019. Cox proportional hazard regression analysis was conducted to evaluate the risk of CVD and mortality, adjusting for potential confounders, including lifestyle behaviors.

Results: The highest UGS coverage was associated with a reduced risk of CVD (aHR = 0.84; 95%CI, 0.77-0.91), with a significant trend (P for trend < .001). These overall trends remained consistent among various CVD subtypes. A reduced cardiovascular mortality risk was observed in the highest UGS coverage group (aHR = 0.74; 95%CI, 0.56-0.97).

Conclusions: This study identified an association between higher levels of UGS coverage and a reduced risk of both CVD and CVD-related mortality. The study holds significant value in focusing on individuals residing within the same area. Therefore, UGS should be considered as a key factor in future urban planning efforts to reduce the burden of CVD and associated mortality.