Exercising under stress could double your risk of a heart attack, according to new research published in the journal Circulation. The study, by McMaster University in Canada, involved 12,461 cardiac arrest patients from 52 countries with an average age of 58.
The participants each completed a questionnaire on the events leading up to their first heart attack. The researchers found a link between emotional turmoil and physical exertion and a higher risk of heart attack, which remained when other risk factors such as smoking and high blood pressure were taken into account.
The researchers also discovered that those who were emotionally upset while taking part in strenuous physical activity were over three times more likely to have a heart attack.
Dr. Andrew Smyth, the study’s lead author, said:‘[Emotional and physical factors] can raise blood pressure and heart rate, changing the flow of blood through blood vessels and reducing blood supply to the heart. This is particularly important in blood vessels already narrowed by plaque, which could block the flow of blood leading to a heart attack.’
‘Regular physical activity has many health benefits, including the prevention of heart disease, so we want that to continue. However, we would recommend that a person who is angry or upset who wants to exercise to blow off steam not go beyond their normal routine to extremes of activity.’
This was a multi-centre case crossover study looking at the precipitating factors involved in heart attack. It observed 12461 patients, and tried to elucidate the precipitating activities and triggers that may have been involved in the eventuality of a first heart attack. The rationale was that >90% of MIs were attributable to exposure to 9 risk factors long term.
Prior studies suggested that physical activity, emotional upset and anger were related to precipitating the cardiac event. The study looked at patients in different countries to see whether the precipitating factors were similar across different geographical circumstances.
A standardised questionnaire and examination was performed by study participants, whereby subjects were asked questions such as ‘Were you engaged in heavy physical exertion?’ and ‘Were you angry or emotionally upset?’ in the 1 hour before symptoms commenced. Control participants were asked the same questions pertaining to the last 24 hours. Socioeconomic data was also collected, as was anthropometric data and a medical history.
Ultimately, the results suggested that anger or emotional upset was reported by 14.4% of participants during the case period and 9.9% during the control period.
However, I have reservations about the nature and design of the study – the participants who had cardiac events also acted as their own controls in the crossover, and this could be subject to recall bias. In addition, while stress and exertion may well precipitate a cardiac event, the study sought to find whether these factors existed and consequently, the study could not be argued as being equipoise. It is similar to me asking a question in General Practice while nodding my head. I am guilty of this from time to time; subliminally, I am looking for a particular answer as opposed to asking the patient openly what happened on the preceding day.
It also looks specifically at hospitalised heart attacks, and therefore may select against the other presentations that could occur.
Lastly, it could also be argued: ‘So what?’. Cardiac events invariably could have a precipitant. They also could not; what the goal in the research is is questionable. Do we avoid stress, emotional upset or anger to stop having heart attacks? I feel this is part of life; and a daily occurrence, unless we happen to live in a monastery.