A single drop in temperature over 2-6 days increases the risk of heart attack by 10%: study

Our hearts are sensitive to weather changes. Adding to the evidence for this link, scientists have made a remarkable discovery about the impact of short-term exposure to icy on heart health. Even a petite drop in temperature, just one unit over two to six days, can augment the risk of a heart attack by up to 11%, a recent study revealed.

In the newest test In their study, published in the JACC Journals, the researchers examined the short-term effects of lower air temperatures and icy waves on the risk of hospitalization for different types of myocardial infarction among 120,380 people from the SWEDEHEART registry in Sweden.

The researchers then found that a short-term reduction in temperature of just 1 unit over 2 to 6 days was associated with a significant augment in the rate of heart attacks: an overall augment of about 10% for all types of heart attacks, an 11% augment for non-ST-segment elevation myocardial infarction (NSTEMI), and an 8% augment for ST-segment elevation myocardial infarction (STEMI).

The study also found that when icy snaps or a sudden drop in temperature occurred during the same 2- to 6-day period, the risk of a complete heart attack increased by about 8%. Meanwhile, the risk of NSTEMI increased by about 7% and the risk of STEMI increased by about 10%.

Chilly waves were defined as periods of at least two consecutive days in which the mean daily temperature was below the 10th percentile of temperatures recorded during the study.

“This nationwide study reveals that short-term exposure to colder air temperatures and icy waves is associated with an increased risk of hospitalization for myocardial infarction (MI) two to six days later, suggesting that individuals may be particularly susceptible to acute cardiac events during periods of icy stress,” said Wenli Ni, lead author of the study in press release.

The researchers also found that exposure on days zero to one reduced the risk of hospitalization for a heart attack, possibly because people stayed indoors or delayed seeking care in icy weather. But these behaviors are short-lived and may contribute to increased hospitalizations two to six days later.

The results not only reveal a significant link between exposure to icy weather and the risk of heart attack, but also point to a delayed effect that peaks several days after the icy snap, said JACC Editor-in-Chief Harlan M. Krumholz, Ph.D.

“These findings also underscore the urgent need for targeted interventions to protect vulnerable populations during and, in particular, after icy stress,” Dr. Krumholz said.