A large body of research has reported that women may present differently than men in terms of MI. A study published Feb. 22 in the Journal of the American Medical Association reaffirmed this observation when researchers reported that women were more likely to present without chest pain, but also had higher rates of mortality.
“Optimal recognition and timely management of myocardial infarction (MI), especially for reducing patient delay in seeking acute medical care, is critical,” according to background information from the study. However, previous research has shown that younger women with MI may have a higher risk factor for mortality compared with men due to the fact that often they present without chest pain.
Women and men present differently with MI. To better understand sex differences in MI presentation, John G. Canto, MD, MSPH, of the Watson Clinic and Lakeland Regional Medical Center in Lakeland, Fla., and colleagues, conducted an analysis of 1,143,513 patients within the National Registry of MI (NRMI) database (1994-2006) to examine the association of those hospitalized for MI between sex and symptom presentation.
Of the total patient cohort, 481,581 were women and 661,932 were men. Women presenting with MI tended to be older than men, 73.9 years vs. 66.5 years, respectively. While MI patients who presented without chest pain tended to have a higher frequency of diabetes and delayed hospital arrival, those who presented with chest pain had higher instances of STEMI and anterior MI.
The authors also reported that those patients who presented without chest pain were less likely to receive PCI or fibrinolytic therapies, and were also less likely to receive aspirin or other antiplatelet agents.
Men younger than age 65 without chest pain and those with chest pain, regardless of age, were more likely to receive CABG surgery. A little more than 35 percent of MI patients presented without chest pain but more women presented without chest pain when compared with men, 42 percent vs. 30.7 percent.
The researchers stratified patients by age: younger than 45 years; 45 to 54 years; 55 to 64 years; 65 to 74 years; and 75 years or older. The researchers found that younger women who presented without chest pain symptoms had a greater rate of hospital mortality rates compared with men, and this trend continued with increasing age.
Canto et al reported that in-hospital mortality rates were 14.6 percent for women compared with 10.3 percent for men.
“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,” the authors wrote. “The three-way interaction (sex, age and chest pain) on mortality was significant.”
The absence of chest pain was linked to increased mortality, particularly among younger women MI patients, the authors said. “[Y]ounger women presenting without chest pain/discomfort had higher hospital death rates than similarly aged men, but this finding reversed with increasing age,” Canto et al wrote.
Despite the fact that women less frequently presented with chest pain upon MI presentation, it was still listed as the most common MI symptom, with 58 percent of women presenting with chest pain and 69 percent of men presenting with chest pain.
The researchers said that the most important step in MI care is identifying new symptoms and seeking medical care.
“Our results show that age is an important factor of sex-based differences in MI presentation, which is especially relevant because women are older than men when they present with an acute coronary syndrome,” the authors wrote.
From the findings, the researchers said that age may be a more important proponent in MI compared with sex in terms of presentation of MI in the absence of chest pain.
“In the current study, comorbidity, clinical characteristics, and, to a modest extent, differences in treatments accounted for the majority of excess mortality in MI patients without chest pain/discomfort, which was especially notable in women younger than 55 years,” the authors wrote.
Although the authors did find sex-based differences of MI presentation, they said the reasons for these differences of presentation remain unknown.
“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