Be extra vigilant about heart attack symptoms during cold weather

21 May 2018

By June Shannon

A new study has found that heart attacks are more likely to strike in cold weather, leading researchers to call for high risk patients to be alerted to symptoms when temperatures drop.

The study was presented at the Asian Pacific Society of Cardiology (APSC) Congress 2018 which took place last week in Taiwan.

Dr Po-Jui Wu, study author and cardiologist at the Kaohsiung Chang Gung Memorial Hospital, Kaohsiung City, Taiwan, explained: “We found that the number of heart attacks (acute myocardial infarctions) fluctuated with the seasons, with more attacks occurring in winter compared to summer. Heart attacks increased dramatically when the temperature dropped below 15 degrees Celsius.”

“When the temperature drops, people at high risk of a heart attack should be put on alert for symptoms such as chest pain and shortness of breath,” said Dr Wu.

“At-risk groups include people who had a previous heart attack, the elderly, or those with risk factors such as diabetes, high blood pressure, smoking, obesity, and sedentary lifestyles. Heart attacks can cause people to die suddenly so it is essential to urgently seek medical assistance when symptoms occur.”

Professor Ian Graham, Chair, Irish Heart Foundation Council on CVD prevention, Professor of Cardiovascular Medicine, Trinity College Dublin and ESC prevention spokesperson, said: “Cold weather is an important environmental trigger for heart attack. Given that the risk is predictable, health authorities should allocate more resources for treating heart attack victims during cold weather. And people at risk of a heart attack should be more vigilant during cold weather and dial emergency at the first sign of symptoms.”

Prof Graham also explained that the cold triggers a sympathetic (adrenalin-like) response to constrict blood vessels (including those to the heart) and increase both blood pressure and heart rate.

The study included 40,524 heart attack patients from the Taiwan National Health Insurance Research Database (NHIRD) and 919,203 adults without a history of heart attack from the Longitudinal Health Insurance Database. Regional climate data was obtained from the Taiwan Central Weather Bureau.

The researchers looked at whether patients were more likely to have experienced certain climate factors before their heart attack than those who did not have a heart attack. They found that lower temperature, temperature fluctuations, and stronger wind separately increased the risk of having a heart attack the following day.

When the lowest temperature of the day was between 15 and 20 degrees Celsius, the relative incidence of acute myocardial infarction increased by 0.45% with each one degree of temperature drop. When the lowest temperature of the day was below 15 degrees Celsius, one degree of temperature drop was associated with a 1.6% of increase in the relative incidence of acute myocardial infarction in Taiwan.

Dr Wu suggested that health systems should send smartphone messages to high risk patients when adverse weather conditions were predicted, to warn them to be extra vigilant. Health systems should also be prepared to cope with more heart attack patients during cold weather.

ENDS