United States: Research shows heart attacks become fatal at higher rates during multiphase heatwaves where temperatures stay elevated during day and night hours.
Heatwaves Pose Greater Danger
Scientists reported in the Journal of the American College of Cardiology on April 1 that compound heatwaves, which persist through the nighttime, cause more fatalities than temperature spikes during daytime alone.
Scientists discovered that compound heatwaves lead people to experience an 86% mortality risk from heart problems, while single-day heatwaves result in death risks of 19%, and nightly heatwaves create a 16% vulnerability.
According to the senior researcher Renjie Chen, a professor at Fudan University School of Public Health in Shanghai, China, “Traditional heatwave definitions fail to capture the full scope of these risks,” US News reported.
Heart Risks Soar During Multiphase Heat Events
The analysis covered approximately 2.4 million Chinese heart disease deaths between 2013 and 2019 and their correlation to temperature measurements through each hour.
Heart-related death probabilities rise steadily throughout a compound heatwave event, yet they show both maximum and declining rates during single-period daytime and nighttime heatwaves.
Heart Failure Surge With Sustained Heat
Research revealed that sudden cardiac arrest deaths, along with heart attack deaths and heart failure deaths, became most common during compound heatwaves.
The risk of sudden cardiac arrest death during compound heatwaves reached 86% higher than during nighttime, and daytime heatwaves brought 37% and 24% increased risks, respectively.
Heart attacks proved fatal at an 88% higher rate when people experienced a compound heatwave, even though nighttime and daytime heatwaves only resulted in 16% and 13% respective rise in deaths.
The risk of heart failure mortality increased by 97% throughout a compound heatwave, although daytime heatwaves and nighttime heatwaves individually raised this risk by just 24%.
The research revealed heart failure deaths were 3 times higher in compound heatwaves, yet they remained at a minimum during both daytime and nighttime heatwaves.
Research findings indicate a need to enhance heat protection strategies, which include building both city cooling shelters and improving residential climate control systems, according to scientists, US News reported.
Furthermore, as Chen stated, “Given the increasing frequency and intensity of compound heatwaves due to climate change, our findings highlight the need for disease-specific prevention strategies and revised public health guidelines to better protect at-risk populations.”