By Elodie Vaz | Published on March 27, 2026 | 4 min read
Cardiovascular
diseases are the leading cause of death in many countries. While their classic
determinants are well identified, the influence of environmental
factors—particularly temperature—remains insufficiently integrated into
prevention strategies. Yet exposure to extreme climatic conditions may
significantly modulate the risk of cardiovascular events.
Quantifying
the impact of cold on mortality
A study
published on March 24 in the American Journal of Preventive Cardiology
and presented at the annual congress of the American College of Cardiology
(ACC.26) aimed to comprehensively assess the association between ambient
temperatures and cardiovascular mortality in the United States. It addresses a
gap in large-scale data, as previous research was often limited to specific
regions or populations.
As the lead
author, Pedro Rafael Vieira De Oliveira Salerno, notes: “this is the first time
we have concrete figures for most of the United States, and we found that the
burden of excess deaths associated with cold is substantial.”
A
population-based analysis over two decades
Researchers
analyzed data from 819 U.S. locations, representing approximately 80% of the
population aged over 25. The study spans a twenty-year period, from 2000 to
2020, correlating monthly temperatures with total cardiovascular deaths.
This
approach identified an optimal temperature associated with the lowest
mortality, estimated at 23°C. Variations around this threshold were then
analyzed to assess their impact on mortality.
A
U-shaped relationship dominated by the effect of cold
The results
reveal an asymmetric U-shaped relationship between temperature and
cardiovascular mortality. While extreme temperatures—both cold and heat—are
associated with increased deaths, the impact of cold is markedly greater.
Over the
study period, cold was responsible for approximately 40,000 additional
cardiovascular deaths per year, representing 6.3% of all deaths related to
these conditions, with a total of 800,000 deaths over twenty years. By
comparison, extreme heat was associated with around 2,000 additional deaths per
year.
These
effects can be explained by several pathophysiological mechanisms:
vasoconstriction, increased blood pressure, and activation of inflammatory
processes—all factors that promote cardiovascular events. Older populations and
patients with chronic diseases appear particularly vulnerable.
Increased
vulnerability in the context of epidemiological transition
The study
also highlights the interaction between climatic conditions and the rising
prevalence of chronic diseases. “With increasing rates of chronic conditions
such as diabetes, heart failure, and chronic kidney disease in the United
States, we can expect a growing number of individuals to be more vulnerable to
the effects of extreme temperatures,” explains Professor Salerno.
Anticipating
an underrecognized risk
These
findings call for a reassessment of the role of cold in public health policies
and climate adaptation strategies. “We tend to focus on the impacts of climate
change related to heat, but climate change also includes extreme cold. We need
to implement mitigation measures not only for heat but also for cold,” the
professor emphasizes.
Beyond
prevention, these data also have organizational implications. “It is important,
both for public health planning and for institutions, to anticipate an increase
in emergency service calls and in-hospital mortality during cold periods. Our
systems must be prepared for this influx of patients,” he adds.
Toward
climate-informed medicine
Despite
certain limitations—particularly the use of monthly data and a population-level
analysis—this study provides a robust framework for understanding the impact of
temperature on cardiovascular health.
At a time
when climate change is reshaping risk profiles, these findings support a more
systematic integration of climatic variables into cardiovascular prevention.
Such an approach could ultimately contribute to a more anticipatory form of
medicine at the intersection of environment and health.
Read
next: Less plaque, but not less risk: a
female paradox in coronary artery disease
About the Author – Elodie Vaz
Health journalist, CFPJ graduate (2023).
Élodie explores the marks diseases leave on bodies and, more broadly, on
human life. A registered nurse since 2010, she spent twelve years at patients’
bedsides before exchanging her stethoscope for a notebook. She now investigates
the links between environment and health, convinced that the vitality of life
cannot be reduced to that of humans alone.
