A recent multi-institutional study led by Harvard T. H. Chan School of Public Health’s Center for Climate, Health, and the Global Environment has shed light on the impact of ambient temperatures on cardiovascular mortality among Swedish patients with heart failure. The research, published in JAMA Cardiology, revealed that short-term exposure to both low and high temperatures was associated with an increased risk of cardiovascular mortality, with heat-related risks intensifying in the years between 2014 and 2021.
With the growing concerns surrounding climate change and its effects on human health, the study aimed to investigate the relationship between temperature extremes and mortality in patients with heart failure. The findings highlighted a U-shaped relationship between temperature exposure and mortality, with both cold and hot extremes posing a higher risk, particularly at lower temperatures.
The study analyzed data from 250,640 patients with heart failure who passed away between 2006 and 2021, utilizing a case-crossover study design to examine the effects of short-term temperature exposure on all-cause and cardiovascular mortality. By mapping daily outdoor temperature and air pollution levels to each participant’s location, researchers were able to assess the impact of temperature fluctuations on mortality rates.
The results indicated that low temperatures increased all-cause mortality by 13% and cardiovascular mortality by 16%, while high temperatures led to a 5% increase in all-cause mortality and an 8% increase in cardiovascular mortality, particularly in the later years of the study. It was also observed that heat-related mortality risk was more pronounced in the period from 2014 to 2021 compared to the earlier years.
Certain subgroups of patients were found to be more vulnerable to temperature-related mortality risks. Men, individuals with diabetes, and those using diuretics were more susceptible to cold temperatures, while patients with atrial fibrillation or flutter and those exposed to higher ozone levels faced higher mortality risks during heatwaves.
In conclusion, the study emphasizes the importance of considering the impact of temperature extremes on cardiovascular mortality among patients with heart failure. The findings suggest that both low and high temperatures can significantly increase the risk of mortality in this population, with heat-related risks appearing to escalate over time. This research underscores the need for targeted interventions and public health strategies to mitigate the adverse effects of temperature fluctuations on vulnerable populations.
Written by Justin Jackson and edited by Sadie Harley, this article provides valuable insights into the complex relationship between ambient temperatures and cardiovascular mortality in patients with heart failure. For more information, you can access the full study published in JAMA Cardiology. Remember, your support helps keep independent science journalism alive, so consider making a donation to support our work.
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