Thursday January 31 2008
The risk of an acute cardiovascular event such as heart attack doubled during a match
“Men are three times more likely to have heart attacks on days when their national football team is playing in a major match,” The Daily Telegraph reported. The newspaper continued that a German study has discovered that during the 2006 World Cup, there were massive increases in the number of heart attacks and other coronary problems. The problems peaked during particularly exciting matches, such as those with penalty shoot-outs.
The researchers who carried out the study advised that the effect was so significant, that men with known heart problems should be given medication before watching a big match.
This story is based on a study that carried out a reliable analysis on local German residents who experienced acute cardiovascular problems during the 2006 World Cup. It found that hospital admissions for heart attacks, severe angina and irregular heartbeats increased by about two to three times on the seven days that Germany played, compared to the 24 days that they did not play, periods before and after the World Cup and at the same time of year in 2005 and 2003.
This study strengthens the evidence that stressful events and emotions can trigger heart attacks and provides a warning for people with known heart disease to be aware of the risks and the need to take appropriate precautions.
Where did the story come from?
Dr Ute Wilbert-Lampen and colleagues from emergency clinics and hospitals around Munich in Bavaria, conducted the research. The study was supported by a grant from the Else Kröner-Fresenius Foundation. It was published in the peer-reviewed: The New England Journal of Medicine.
What kind of scientific study was this?
The researchers studied patients who had contacted emergency services and had been treated by an emergency doctor at the time of the World Cup, the June 9 to July 9 2006. Fifteen sites around the city and suburbs of Munich were selected; these included rural clinics as well as air rescue services and intensive care ambulances. The diagnoses of heart attack, severe (unstable) angina, irregular heart rhythm (arrhythmia) or cardiac arrest were made by an emergency medicine doctor. The researchers used the registered address of patients to make sure that only local German residents were included and visitors to the area were excluded.
Details were collected about the emergencies and the patients involved; including the date, time and location of the call, and the onset of symptoms and initial and final diagnosis. The patient’s age, sex and any known past history of heart disease was also documented.
This cross sectional study used a pooled group of historical and current controls. The researchers compared the rate of the emergency events on the seven days that Germany played with the daily average during four other time periods: May 1 to July 31 2003, May 1 to July 31 2005 and the two periods before and after the 2006 World Cup (May 1 to June 8 and July 10-31 July 2006). The year 2004 was excluded because of possible effects from the European Soccer Championship in Portugal that year.
What were the results of the study?
Four thousand, two hundred and seventy-nine people had acute cardiovascular events during the times studied, with 302 of these events occurring over the seven days that Germany had World Cup matches. Compared to the control period, six of the seven games that Germany played were associated with an increase in the number of cardiac emergencies.
Taking all seven games, the number of emergencies per day (the rate) was 2.66 times that of the control periods, and this difference was statistically significant (i.e. less likely to have occurred by chance). The rate of male emergencies was 3.26 times the rate of the control period, while the female rate was 1.82 times that of the control period.
Almost half of the people who had emergencies when Germany played already had heart disease and the rate of emergency for them was four times the rate during the control period.
What interpretations did the researchers draw from these results?
The researchers concluded, “viewing a stressful soccer match more than doubles the risk of an acute cardiovascular event (consisting of both the heart attacks and irregular heart rhythms)”.
They suggest that these additional emergencies were triggered by emotional stress in relation to soccer matches involving the national team. They call for future studies that assess how other sporting events trigger stress, and for studies that analyse the effectiveness of treatments that could reduce the stress-related excess risk of cardiovascular events.
In view of this excess risk, they call for urgent action on preventive measures, particularly for men with known coronary heart disease.
What does the NHS Knowledge Service make of this study?
There are several advantages to this study. Before the study began, the researchers clearly described the subject of interest and specified how they would collect data in a strictly defined geographical area. They were careful to choose a control group who suffered events at around the same time of year, as it is known that heart attacks are more common in winter. In addition to this, they took into account the temperature, barometric pressure and air pollution, which can also affect rates of heart attack. They also looked at the time between the beginning of a match and the onset of symptoms and showed that most of the emergency events occurred within an hour of the start of the match. The researchers acknowledge some remaining limitations:
- Because some diagnoses were not made in a hospital, the researchers were unable to confirm a heart attack using a troponin blood test (a test that is used to confirm a heart attack or severity of angina). This meant that there could be some doubt about the exact numbers of patients who had suffered angina compared to a full heart attack.
- Their results do not identify or control for potential triggers other than stress, such as lack of sleep, heavy eating, drinking, smoking or failure to comply with medication on the days of a game. It is possible that these factors contributed in some way to the results shown in this study.
Overall, this study provides good evidence that stressful events and emotions can trigger heart attacks and provides a warning for people who already know they have heart disease.
Sir Muir Gray adds...
Bill Shankly once said that football was not a matter of life and death, it was much more than that.