Long-term PM_2.5 exposure and survival among cardiovascular disease patients in Beijing, China

Previous studies have proved that particulate air pollution was related to adverse cardiovascular effects. However, most studies focused on the acute effects of short-term fine particulate matter (PM_2.5) exposure and the general population. Evidence from long-term cohort studies based on the cardiovascular disease (CVD) patients was scarce. Our study aimed to explore the impact of long-term exposure to PM_2.5 on the mortality among post-CVD patients. This is a cohort study that involved 5143 post-CVD patients in Beijing, China. We collected records of CVD patients from hospitals in Beijing, China from 1 January 2012 to 31 December 2012 and followed up these patients from hospital admission until December 31, 2016. The vital status of the patients was determined using the National Death Surveillance Point System (DSPs). The PM_2.5 concentrations were obtained from the Atmospheric Composition Analysis Group. The Cox regression models were used for data analyses. Our findings suggested that increased mortality of CVD patients with an HR of 1.43 (95% CI: 1.24, 1.63) was related to long-term exposure to PM_2.5. The association was stronger for cardiovascular-related mortality, especially for mortality from myocardial infarction (MI). The HR for any CVD mortality was 1.57 (95% CI: 1.27, 1.94), HR for MI mortality was 1.82 (95% CI: 1.16, 2.83). Long-term PM_2.5 exposure may significantly affect the survival of CVD patients. Compared with the general population, patients with CVD are more susceptible to PM_2.5 exposure. Increased attention to the management of CVD patients is warranted.