Impact of climate change and air pollution on cardiovascular disease: A systematic review and meta-analysis protocol

Climate change and increasing environmental pollution are emerging as significant threats to global health, notably through their impact on cardiovascular diseases (CVD). The World Health Organization (WHO) attributes millions of premature deaths annually to air pollution and extreme temperatures. Despite extensive research on air pollution and temperature extremes separately, their combined effects on cardiovascular health remain inadequately explored.

We plan to conduct a systematic review and meta-analysis to assess the impact of climate change, including extremes of temperature and air pollution, on CVD. We will search PubMed, CINAHL, SCOPUS, ClinicalTrials.gov, and additional databases for studies published between August 12, 2019, and August 11, 2024. The review will include observational and quasi-experimental (pre and post-test) studies. Data extraction and quality assessment will be performed using EndNote, Rayyan.ai, and the National Heart, Lung, and Blood Institute (NHLBI) quality appraisal tool. The statistical analysis will be conducted using RevMan 5.4, with risk ratios, mean differences, and heterogeneity evaluated.

This review aims to synthesize evidence on how ambient air pollutants (PM_2.5, CO, O₃) and extreme temperatures contribute to cardiovascular morbidity and mortality. It will highlight the synergistic effects of air pollution and temperature extremes, with a particular focus on low- and middle-income countries where the burden is most pronounced.

By integrating the impacts of both climate change and air pollution on cardiovascular health, this review will provide comprehensive insights into the global health burden of CVD. The findings will inform public health strategies and interventions to mitigate the adverse effects of environmental factors on cardiovascular health.