More visible greenspace, stronger heart? Evidence from ischaemic heart disease emergency department visits by middle-aged and older adults in Hubei, China

Awareness is increasing that greenspace is beneficial for people's heart health. While a plethora of studies have focused on the relationship between neighbourhood greenspace and cardiovascular diseases in the general population, scant attention has been given to ischaemic heart disease (IHD) emergency department visits for middle-aged and older adults. This study aimed to systematically explore the association between residential street view greenspace (SVG) exposure and IHD emergency department visits for middle-aged and older adults in Chinese cities. The IHD mortality and recovery time of surviving patients were treated as dependent variables. We used street view data to assess residential SVG, and we also distinguished between trees (SVG-tree) and grasses (SVG-grass) when calculating SVG. The results showed that SVG-grass is negatively associated with IHD mortality and recovery time from IHD. However, there is no evidence that SVG-tree is related to IHD. Hence, the stratified analysis indicates that that the effect of SVG on IHD varies significantly by individual demographic and socioeconomic characteristics. Male patients, older patients and patients living in low-income neighbourhoods can benefit more from SVG exposure. Our findings suggest the necessity of providing sufficient residential visible vegetation, especially grassland, to promote heart health in Chinese urban settings.