Health systems should warn high risk patients by smartphone when cold weather is predicted

Be extra vigilant about heart attack symptoms during cold weather. That’s the advice from the authors of a large Taiwanese study which found that heart attacks are more likely to strike when temperatures drop. The study is being presented at the Asian Pacific Society of Cardiology (APSC) Congress 2018.

Dr Po-Jui Wu, study author and cardiologist, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung City, Taiwan, explained: “We found that the number of heart attacks 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, 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.”

This study assessed the association between climate and heart attack occurrence. To the best of the authors’ knowledge, it is the largest study on this topic in Taiwan. The study used three databases covering the period 2008 to 2011. This is the first time these three large databases have been combined to investigate the impact and interaction of weather on heart attack occurrence.

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 the participants 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 said: “Despite improved treatment for cardiovascular disease and almost 100% coverage of citizens by our national health insurance programme, the number of acute myocardial infarction patients is increasing and overall cardiovascular mortality is rising in Taiwan. We speculate that this is the result of societal ageing, extreme change of climate, and environmental pollution.”

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

ProfessorJiunn-Lee Lin,Chair of the APSC Congress 2018 and President, Taiwan Society of Cardiology, concluded: “This study from Taiwan adds important information on how to prevent acute myocardial infarction.

Source: European Society of Cardiology (ESC)