Residential exposure to greenness and mortality in a cardio-oncologic population

Abstract Background Knowledge is lacking on the relationship between greenness and all-cause mortality in cancer survivors who subsequently experience an acute coronary syndrome (ACS), a cardio-oncologic population. We aimed to investigate the association between residential greenness exposure and mortality in this cardio-oncologic population. Methods Cancer survivors undergoing percutaneous intervention at a medical center in Israel between 2004 and 2014 were included in the study. Clinical data were collected from medical records during index hospitalization. Residential greenness was estimated by the normalized difference vegetation index (NDVI), a satellite-based index derived from Landsat imagery at 30 m spatial resolution, with larger values indicating higher levels of vegetative density (ranging between -1 to 1). NDVI values were retrieved for a buffer within 300 m radius around each patient’s home address. Mortality follow-up data (through the end of 2021) were obtained from the Ministry of Health. Data on residential socioeconomic status (rSES) were obtained from Central Bureau of Statistics based on home addresses. Cox models were used to assess the hazard ratios (HRs) for all-cause mortality per 1SD increase in NDVI. Results Among 1,331 patients analyzed median age, 77 (IQR 69-83) y, 373 (28%) females, the mean (SD) NDVI-300 was 0.12 (0.03). During a median follow-up period of 12.0 (IQR 9.2-14.7) years, 883 (66%) participants died. After adjustment for potential confounding factors, including rSES, smoking, and residential NOx exposure, NDVI-300 was linearly associated with lower mortality HR (95% CI) = 0.93 (0.86, 1.00); p=.04. Individuals with lower rSES scores had a lower point estimate for the HR, compared with individuals with higher rSES (Figure 1). The association was more robust among individuals with recently diagnosed cancer (up to ten years prior to ACS onset; Figure 2). Conclusions In a cohort of cardio-oncologic patients, greenness was associated with lower mortality. The association was strongest among individuals from deprived neighborhoods and with recently diagnosed cancer.