Improvements in heart disease prevention and treatment have led to substantial declines in cardiovascular deaths over recent decades. However, climate change caused by the continued combustion of fossil fuels may undermine this progress. NASA reports that the average global temperature has risen by more than two degrees Fahrenheit over the last century, leading to significant shifts in weather patterns, ecosystem disturbances, and rising sea levels. Notably, the ten hottest years on record have all occurred in the past decade.
CARDIOVASCULAR HEALTH ; SYSTEMATIC REVIEW OF ENVIRONMENTAL STRESSORS
In a comprehensive study, researchers at Beth Israel Deaconess Medical Center (BIDMC) conducted a systematic review of 492 observational studies to explore the link between climate change-related environmental stressors and cardiovascular disease (CVD). The findings, published in JAMA Cardiology, reveal that extreme temperatures and hurricanes are strongly associated with increased CVD mortality and incidence, disproportionately affecting older adults, racial and ethnic minorities, and individuals from lower wealth communities.
CARDIOVASCULAR HEALTH ; THE IMPACT OF EXTREME TEMPERATURES
“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,” explained Dhruv S. Kazi, associate director of the Richard A. and Susan F. Smith Centre for Outcomes Research at BIDMC. Additionally, long-term changes in climate are projected to reduce agricultural productivity and the nutritional quality of food supplies, further compromising cardiovascular health.
CARDIOVASCULAR HEALTH ; SCREENING AND STUDY SELECTION
Kazi and his team screened nearly 21,000 peer-reviewed studies published between 1970 and 2023. These studies evaluated associations between acute cardiovascular events, cardiovascular mortality, CVD healthcare utilization, and climate change-related phenomena such as extreme temperatures, wildfires, ground-level ozone, and extreme weather events including hurricanes, dust storms, and droughts.
CARDIOVASCULAR HEALTH ; KEY FINDINGS FROM THE REVIEW
Temperature and Cardiovascular Disease; Out of the 492 global observational studies, 182 examined the impact of extreme temperature, 210 focused on ground-level ozone, 45 investigated wildfire smoke, and 63 studied extreme weather events. The results showed that exposure to extreme temperature significantly increased the incidence of cardiovascular disease and mortality. The impact varied based on the severity and duration of temperature exposure. For instance, extreme weather events like hurricanes and floods were linked to increased cardiovascular risk, with effects lasting months or even years beyond the event.
Wildfire Smoke and Cardiovascular Events; Studies on wildfire smoke exposure presented mixed results. Some indicated an increased risk of events like cardiac arrest, while others did not. Given the frequent exposure to wildfire smoke, particularly in areas like New York City affected by Canadian wildfires, further research is essential to quantify this risk accurately.
CARDIOVASCULAR HEALTH ; ADDRESSING KNOWLEDGE GAPS
A significant gap identified by the researchers is the lack of data on the impact of climate change-related cardiovascular risk in low-income nations. Only one study included in the review was conducted in a low-income country, and merely five were based in Africa, where the effects of climate change are expected to be severe.
“Though data on outcomes in low-income countries are lacking, our study shows that several environmental stressors that are increasing in frequency and intensity with climate change are linked with increased cardiovascular risk,” said Mary B. Rice, MD, MPH, senior author and a pulmonary and critical care physician at BIDMC.
CARDIOVASCULAR HEALTH ; RECOMMENDATIONS FOR CLINICIANS AND HEALTH SYSTEMS
Evaluating Cardiovascular Risk; The findings suggest that clinicians should assess patients’ CVD risk from climate change exposures based on individual, community, and health system factors. Clinicians should also be aware of local environmental exposure risks, such as extreme temperatures, wildfire smoke, or extreme weather events. In hurricane or flood-prone areas, healthcare providers should help patients develop contingency plans to ensure uninterrupted access to medications and healthcare services.
Building Resilient Health Systems; Health systems need to evaluate the resilience of their infrastructure to withstand climate change impacts. This includes ensuring reliable power supplies, robust supply chains, and preparedness for natural disasters that could disrupt healthcare delivery.
Climate change, driven by fossil fuel combustion, is already adversely affecting cardiovascular health worldwide. Immediate action is required to mitigate these risks, particularly among the most vulnerable populations. The study underscores the urgent need for comprehensive strategies that incorporate environmental, social, and healthcare measures to protect cardiovascular health in the face of a changing climate.
FAQs
How does climate change affect cardiovascular health?
Climate change affects cardiovascular health through various pathways, including extreme heat, air pollution from wildfires, psychological distress from natural disasters, and disruptions in healthcare delivery.
What populations are most at risk?
Older adults, racial and ethnic minorities, and individuals from lower wealth communities are disproportionately affected by climate change-related cardiovascular risks.
What environmental stressors were studied?
The study examined extreme temperatures, wildfire smoke, ground-level ozone, and extreme weather events like hurricanes and floods.
What are the recommendations for clinicians?
Clinicians should evaluate patients’ cardiovascular risk from climate change exposures and help them develop contingency plans for extreme weather events. They should also be aware of local environmental exposure risks.
Why is further research needed?
Further research is needed to accurately quantify the cardiovascular risk associated with wildfire smoke and to understand the impacts in low-income countries, which are expected to be disproportionately affected by climate change.
What actions can health systems take?
Health systems should evaluate and strengthen their infrastructure’s resilience to climate change, ensuring reliable power supplies, robust supply chains, and preparedness for natural disasters.
