Heat-related cardiovascular hospitalizations are on the rise 

A new study led by experts at Monash University highlights the risks of global warming for individuals with cardiovascular issues. According to the research, rising temperatures over the last two decades have led to a substantial increase in heat-related cardiovascular hospitalizations.

Heart conditions such as coronary artery disease and arrhythmias are exacerbated by extreme temperatures, both hot and cold, increasing the risk of a fatal stroke and heart attack. Climate change is increasing the frequency, intensity, and duration of extreme temperatures.

Previous studies have found a decrease in the link between extreme heat and cardiovascular deaths, suggesting that people may have adapted to the warming climate. The current research, however, indicates that the correlation between heat and fatal heart events has actually strengthened over time.

“Most studies have only focused on hot temperature and mortality,” explained the researchers. “We aim to investigate the temporal variations in the association between ambient temperature and hospitalizations for cardiovascular diseases.”

The study was focused on data involving 1,855,717 cardiovascular hospitalizations in Queensland between 1995 and 2016. During these years, the daily average temperature in Queensland increased from 20.9 degrees Celsius to 21.7 degrees Celsius, and the annual number of cardiovascular hospitalizations increased from 46,730 to 123,477. 

The relative risk of cardiovascular hospitalization associated with high temperatures was found to increase over time, regardless of the patients’ age, sex, or climate zone. On the other hand, the impact of cold temperatures was found to decrease over time. 

The adverse effects of heat were stronger in male patients. The impacts of heat were also stronger among people less than 70 years old compared to those over 70.

“The findings highlight that Queensland people have adapted to the impacts of cold temperatures, but not high temperatures,” wrote the study authors.

“Given the increased associations between hot temperatures and cardiovascular hospitalization and the acceleration of global warming, we highlight a worrying trend that the burden of cardiovascular healthcare facilities is to increase over time on high temperature days.”

The study is published in the journal PLOS Medicine.

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By Chrissy Sexton, Earth.com Staff Writer