Study unveiles Impact of Temperature on Cardiovascular Mortality: A Global Perspective

The study that tracked mortality over 20 years revealed that worldwide, nearly one in 10 cardiovascular deaths may be attributed to “nonoptimal” temperatures.

The findings suggest that globally, 1,801,513 cardiovascular deaths yearly were linked to nonoptimal temperatures over the two decades, comprising 8.86% of total global cardiovascular (CV) deaths, or 26 excess cardiovascular deaths per 100,000 people.

"Nonoptimal temperatures contribute substantially to CV mortality, with heterogeneous spatiotemporal patterns," the researchers wrote. "There is a need for effective mitigation and adaptation strategies, especially given the increasing heat-related cardiovascular deaths amid climate change."

The association between nonoptimal temperatures and cardiovascular mortality risk is recognized. However, there is a lack of comprehensive global assessment of this burden. Samuel Hundessa from Monash University in Melbourne, Victoria, Australia, and colleagues aimed to assess the global cardiovascular mortality burden attributable to nonoptimal temperatures and investigate spatiotemporal trends.

For this purpose, a 3-stage analytical approach was applied using daily cardiovascular deaths and temperature data from 32 countries. Firstly, the research team estimated location-specific temperature–mortality associations considering nonlinearity and delayed effects. Second, they developed a multivariate meta-regression model between location-specific effect estimates and five meta-predictors. Third, cardiovascular deaths associated with nonoptimal, hot, and cold temperatures for each global grid (55 km × 55 km resolution) were estimated, and researchers explored temporal trends from 2000 to 2019.

The study led to the following findings:

• Globally, 1,801,513 annual cardiovascular deaths were associated with nonoptimal temperatures, constituting 8.86% of total cardiovascular mortality corresponding to 26 deaths per 100,000 population.
• Cold-related deaths accounted for 8.20%, whereas heat-related deaths accounted for 0.66%.
• The mortality burden varied significantly across regions, with the highest excess mortality rates observed in Central Asia and Eastern Europe.
• From 2000 to 2019, there was a decrease in cold-related excess death ratios, while heat-related ratios increased, resulting in an overall decline in temperature-related deaths.
• Southeastern Asia, Sub-Saharan Africa, and Oceania observed the greatest reduction, while Southern Asia experienced an increase.
• The Americas and several regions in Asia and Europe displayed fluctuating temporal patterns.

As the global community grapples with the escalating challenges posed by climate change, initiatives aimed at minimizing the health risks associated with temperature extremes are imperative. Through collaborative action and evidence-based interventions, policymakers and stakeholders can mitigate the adverse effects of nonoptimal temperatures on cardiovascular health, ensuring a healthier and more sustainable future for all.

Reference:

Hundessa S, Huang W, Zhao Q, et al. Global and regional cardiovascular mortality attributable to nonoptimal temperatures over time. J Am Coll Cardiol. 2024;83:2276-2287.