Effect of Air Pollution on Heart Failure: Systematic Review and Meta-Analysis

BACKGROUND: Heart failure (HF) poses a significant global disease burden. The current evidence on the impact of air pollution on HF remains inconsistent. OBJECTIVES: We aimed to conduct a systematic review of the literature and meta-analysis to provide a more comprehensive and multiperspective assessment of the associations between short- and long-term air pollution exposure and HF from epidemiological evidences. METHODS: Three databases were searched up to 31 August 2022 for studies investigating the association between air pollutants (PM2.5, PM10, NO2, SO2, CO, O3) and HF hospitalization, incidence, or mortality. A random effects model was used to derive the risk estimations. Subgroup analysis was conducted by geographical location, age of participants, outcome, study design, covered area, the methods of exposure assessment, and the length of exposure window. Sensitivity analysis and adjustment for publication bias were performed to test the robustness of the results. RESULTS: Of 100 studies covering 20 countries worldwide, 81 were for short-term and 19 were for long-term exposure. Almost all air pollutants were adversely associated with the risk of HF in both short- and long-term exposure studies. For short-term exposures, we found the risk of HF increased by 1.8% (RR = 1.018, 95% CI: 1.011, 1.025) and 1.6% (RR = 1.016, 95% CI: 1.011, 1.020) per 10 µg/m3 increment of PM2.5 and PM10, respectively. HF was also significantly associated with NO2, SO2, and CO, but not O3. Positive associations were stronger when exposure was considered over the previous 2 d (lag 0-1) rather than on the day of exposure only (lag 0). For long-term exposures, there were significant associations between several air pollutants and HF with RR (95% CI) of 1.748 (1.112, 2.747) per 10 µg/m3 increment in PM2.5, 1.212 (1.010, 1.454) per 10 µg/m3 increment in PM10, and 1.204 (1.069, 1.356) per 10-ppb increment in NO2, respectively. The adverse associations of most pollutants with HF were greater in low- and middle-income countries than in high-income countries. Sensitivity analysis demonstrated the robustness of our results. DISCUSSION: Available evidence highlighted adverse associations between air pollution and HF regardless of short- and long-term exposure. Air pollution is still a prevalent public health issue globally and sustained policies and actions are called for to reduce the burden of HF. https://doi.