A study in the February issue of JAMA, reports that female heart attack patients are more likely to go to hospital without chest pain and have a much higher rate of in-hospital death following a heart attack, compared to men of the same age group. The study, by John G. Canto, M.D., M.S.P.H., of the Watson Clinic and Lakeland Regional Medical Center, Lakeland, Fla., and colleagues, analyzed the links between; the gender of the patient, the symptoms of myocardial infarction (heart attack) they develop, and risk of death in hospital.

The authors state that chest pain is one of the critical symptoms of heart attack, noting that those who do not have such symptoms have a higher short-term mortality rate:

“Optimal recognition and timely management of myocardial infarction [MI; heart attack], especially for reducing patient delay in seeking acute medical care, is critical. The presence of chest pain/discomfort is the hallmark symptom of MI. Furthermore, patients without chest pain/discomfort tend to present later, are treated less aggressively, and have almost twice the short-term mortality compared with those presenting with more typical symptoms of MI.”

The study involved analyzing over 1,143,513 registry patients, from the National Registry of Myocardial Infarction, 1994-2006. Women accounted for 42.1% of such cases and were found to be, on average, older than men at time of hospital presentation. The average age for men at presentation was 67 years, whereas the average female age was 74 years.

The authors add:

“It is plausible that women’s older age at presentation is related to whether they present with chest pain, as well as subsequent hospital mortality. However, a limited number of studies have taken age into account in examining sex differences in MI clinical presentation.”

Around a third – 35.4 percent – of the MI patients did not experience chest discomfort at hospital presentation, with the percentage for women (42.0 percent) being considerably higher than for men (30.7 percent). The analyses found an important association between age and sex, with most of the sex-specific differences in MI presentation found to become less evident as age increased.

Female patients had an in-hospital mortality rate of 14.6 percent, significantly higher than the rate of 10.3 percent among men, the authors found that young women presenting without any chest pains had the highest rates. This suggests that the absence of chest pain among young women with MI could be a key predictor of death.

The authors said:

“Younger women presenting with chest pain/discomfort had a greater hospital case-fatality rate than men with chest pain/discomfort in the same age group, but differences in hospital death rates between men and women decreased with advancing age (no longer significant in the oldest group). These data suggest that the absence of chest pain may be a more important predictor of death in younger women with MI compared with other similarly aged groups.”

There is still a need for further research to be carried out to confirm their findings and provide more insight into the underlying pathophysiology. Without confirmation from other studies, the findings won’t have much influence on health messages given out by providers.

They conclude:

“Our results of sex-based differences in MI symptom presentation in younger patients are provocative and should be confirmed by others with clinical databases of MI or acute coronary syndromes. From a public health perspective, it is appropriate to target high-risk groups for delay (young women) with information on the American Heart Association/National Institutes of Health heart attack message, but until additional research is conducted, the current chest pain/discomfort heart attack symptom message, which targets women and men equally irrespective of age, should remain unchanged.”

Written by Joseph Nordqvist