Abstract 4137820: Extreme heat and cardiovascular disease in a changing climate: An urgent need for risk management and health research

Background: Extreme heat can trigger or exacerbate cardiovascular disease (CVD) through ischemia or thrombosis, and its deleterious impacts are inclined to worsen as increased heat exposure and heightened vulnerability from climate change interacted with natural and social environment. Research Questions: Previous studies have primarily focused on quantifying the increased risk of CVD due to heat exposure, while lacking a comprehensive understanding of the association, underlying mechanisms, and vulnerability in CVD patients. Consequently, there is a scarcity of clinical and public health interventions aimed at preventing the convergence of extreme heat exposure and the risk of CVD within the context of climate change. Methods: We conducted a systematic search in PubMed, Embase, and Web of Science from inception to December, 2023, and we retrieved articles which assessed the effects of extreme heat or climate change on CVD. Results: In this review, we outline the existing evidence on the epidemiology and pathophysiological mechanisms that elucidate how extreme heat affects the risk of CVD. Extreme heat is associated with increased risks for CVD morbidity and mortality, where older persons, low socioeconomic status, pre-existing medical conditions, and unfavorable living environments confer greater susceptibility to heat. The adverse effects of extreme heat on cardiovascular system involved a wide range of complex mechanisms between different organs and regulatory pathways (Figure 1). Additionally, we identify the factors that contribute to the vulnerability of CVD patients to heat exposure. The discrepancy in heat-related risk can be attributed to individual susceptibility, sociocultural factors, population temperature adaptations, and environmental factors. Future climate change is projected to exacerbate the burden of extreme heat, particularly due to the interaction of air pollution, population aging, and urbanization (Figure 2). Conclusions: Addressing extreme heat should be within the framework of the prevention of CVD. Health professionals and scientists are responsible for mitigating the cardiovascular effects mediated by extreme heat, with an emphasis on engaging in risk management tactics and health research to implement preventive strategies. As CVD is a climate sensitive disease, evidence-based interventions during heat extremes are urgently needed to cope with the cardiovascular risks associated with the inevitable trajectory of climate change.