Extremely cold temperatures increase the risk of death in people with cardiovascular disease, new research shows.
If freezing conditions brought heavy snow to much of the UK overnighta study in the journal Circulation warned that people who suffered from conditions such as an irregular heartbeat were at greater risk when the weather turns nasty.
UK weather live updates: coldest day of the year below -15C
For every 1,000 cardiovascular deaths, researchers found that extremely cold days accounted for nine more.
The trend was less pronounced on days of extreme heat, which accounted for an additional two deaths.
It comes after the UK saw temperatures north of 40C during the summer, when there are more deaths among the over-65s reached their highest level since 2004.
Among the types of heart disease, the highest number of excess deaths was found for people with heart failure, with nearly 13 during extremely cold days and nearly three on extremely hot days.
How was the study conducted?
The peer-reviewed global study was conducted by the Multi-Country Multi-City Collaborative Research Network.
It analyzed data from more than 32 million cardiovascular deaths — the leading cause of death worldwide — in 27 countries on five continents between 1979 and 2019.
Deaths were compared to the warmest and coldest 2.5% of days for each city, with those on the “optimal temperature” days, defined as the temperature associated with the lowest death rates.
“One in 100 cardiovascular deaths can be attributed to days of extreme temperatures, and the temperature effects were more pronounced when looking at heart failure deaths,” said study co-author Haitham Khraishah, of the University of Maryland.
“While we don’t know the reason, this may be explained by the progressive nature of heart failure as a disease, predisposing patients to temperature effects.
“This is an important finding, as one in four people with heart failure is readmitted to hospital within 30 days of discharge, and only 20% of heart failure patients survive 10 years after diagnosis.”
Findings ‘show importance of fighting climate change’
More work is needed to develop strategies to mitigate the impact of extreme temperatures in the face of increasing climate change, the researchers conclude.
One suggestion is to introduce targeted warning systems and advice for vulnerable people.
“We need to be aware of emerging environmental risks,” said Harvard University’s Barrak Alahmad.
“I call on the professional cardiology organizations to develop guidelines and scientific statements on the intersection of temperature extremes and cardiovascular health.
“Statements like these allow us to provide more direction to healthcare professionals, as well as identify gaps in the clinical data and future priorities for research.”