Climate Change, Extreme Weather Linked to Heightened Cardiovascular Risk

A new study is sounding the alarm on the impact of climate change and extreme weather patterns on risk of cardiovascular disease-related deaths.

Leveraging data from more than 490 studies, the review identified multiple environmental stressors, including heat waves, hurricanes, and more, were associated with increased cardiovascular risk.

“Climate change is already affecting our cardiovascular health; exposure to extreme heat can adversely affect heart rate and blood pressure; exposure to ozone or wildfire smog can trigger systemic inflammation; living through a natural disaster can cause psychological distress; and hurricanes and floods may disrupt healthcare delivery through power outages and supply chain disruptions; and in the long-term, the changing climate is projected to produce declines in agricultural productivity and the nutritional quality of the food supply, which could also compromise cardiovascular health,” said corresponding author Dhruv S. Kazi, MD, associate director of the Richard A. and Susan F. Smith Center for Outcomes Research at Beth Israel Deaconess Medical Center (BIDMC).² “We know that these pathways have the potential to undermine the cardiovascular health of the population, but the magnitude of the impact, and which populations will be particularly susceptible, need further study.”

Almost every corner of the US has been grappling with extreme weather events in recent years, from wildfires to hurricanes, headlines have been dominated by the impact of climate on life in the country. While many of these events grind day-to-day life to a halt for days, weeks, or even months, the long-term effect on climate events has become a focal point of research efforts in recent years.¹

An example of this growing focus on the effects of climate change on long-term health, the current study was led by Kazi and colleagues at BIDMC to provide an overview of the current evidence on the association between climate change-related stressors and adverse cardiovascular outcomes. Investigators designed their study as a systematic review of PubMed, Embase, Web of Science, and Cochrane Library.¹

Through a search for peer-reviewed publications published from January 1, 1970, through November 15, 2023, investigators identified more than 20,000 articles for inclusion in their review. Following screening, 2564 underwent full-text review and 492 were subsequently included in the systematic review. Of note, for inclusion in the review studies needed to examine associations of extreme ambient temperatures, wildfires and resulting particulate air pollution, ground-level ozone, extreme weather events, such as hurricanes, dust storms, or drought, sea level rise, saltwater intrusion and climate-related migration with acute cardiovascular events, cardiovascular mortality, and cardiovascular disease health care utilization.¹

Of the 492 studies meeting inclusion criteria, 182 were extreme temperature-related, 210 examined ground-level ozone, 45 examined wildfires, and 63 examined extreme weather events. Investigators pointed out they were unable to identify studies examining associations between sea level rise, saltwater intrusion, or climate-related migration and cardiovascular outcomes. Investigators highlighted 91% of studies were rated as being low or probably low risk of bias.¹

Upon analysis, investigators observed a sufficient strength of evidence to draw associations between cardiovascular risk and extreme temperature, ground-level ozone, tropical storms, hurricanes, and cyclones, and dust storms, but evidence appeared limited for wildfire smoke and inadequate for drought and mudslides.¹

Further analysis suggested exposure to extreme temperature was associated with increased cardiovascular mortality and morbidity, but investigators suggested the magnitude of effect varied based on temperature and duration of exposure. Investigators underlined studies indicated ground-level ozone amplified the risk associated with higher temperatures and vice versa.¹

The investigator highlighted the increased cardiovascular risk observed with hurricanes and other extreme weather events persisted for several months after the initial event. Additionally, investigators found older adults, racial and ethnic minoritized populations, and lower-wealth communities were disproportionately affected.¹

“Though data on outcomes on low-income countries are lacking, our study shows that several of the environmental stressors that are already increasing in frequency and intensity with climate change are linked with increased cardiovascular risk,” said senior investigator Mary B. Rice, MD, MPH, a pulmonary and critical care physician in the division of Pulmonary and Critical Care Sleep Medicine at BIDMC.²

References:

1. Kazi DS, Katznelson E, Liu C, et al. Climate Change and Cardiovascular Health: A Systematic Review. JAMA Cardiol. Published online June 12, 2024. doi:10.1001/jamacardio.2024.1321
2. Beth Israel Deaconess Medical Center. Climate change-related disturbances linked to worse cardiovascular health, researchers show. BIDMC of Boston. June 12, 2024. Accessed June 14, 2024. https://www.bidmc.org/about-bidmc/news/2024/06/climate-change-related-disturbances-linked-to-worse-cardiovascular-health-researchers-show.