Over the past 15 years, the medical community has come to understand that heart disease in men and heart disease in women can be very different creatures. From presenting symptoms to treatment choices, gender-based differences apparently affect the outcomes associated with acute coronary syndromes, which involves two of the most serious manifestations of heart disease: unstable angina (UA) and heart attack .

Past research, for example, has shown that short term mortality rates for UA in women are better or equal than in men. Still others have found that, in the short term, mortality rates from heart attack were higher in women than in men. However, none has explored the role of gender on long term (five year) mortality rates over the full spectrum of acute coronary syndromes.

To address this issue, a group of researchers in Canada conducted a seven year study. The purpose of the study was to learn whether or not gender had an effect on long term (five year) mortality rates after unstable angina or heart attack. The study, published in the November 10, 2003 issue of The Archives of Internal Medicine found that while certain women were more likely to be diagnosed with unstable angina, the five-year mortality rate for those women who experience a heart attack was significantly higher than in men.

About the study

The researchers collected information from the Ministry of Health and Wellness database in Alberta, Canada. They examined the files of 22,967 patients who had been diagnosed with acute myocardial infarction (AMI) and 8441 patients who had been diagnosed with unstable angina (UA), all of whom had been discharged from acute care hospitals in Alberta, Canada between April 1, 1993 and March 31, 2000.

The patients were grouped according to their age, gender, and preexisting health conditions or treatment (eg, diabetes, previous heart attack, or previous angioplasty ).

The findings

The researchers found that women who were older and who also suffered from some type of preexisting health condition, such as diabetes, high blood pressure , congestive heart failure (CHF) , or chronic obstructive pulmonary disease (COPD) were more likely to be diagnosed with UA, and less likely (by as much as 30%) to undergo a CABG procedure than men. And while five-year mortality for both genders were similar after UA (women 21.6% vs men 19.5%), it was significantly higher for women after AMI (women 38.5% vs men 26.6%).

How does this affect you?

The researchers found that once admitted to the hospital, women with UA had better long-term survival rates than men. However, this was true only of women over 65 years of age. When women were admitted to the hospital during a heart attack, however, this advantage was lost and in some cases reversed. Interestingly, this loss occurred only in women who were under 65 years of age, a finding that supports other studies showing a greater risk of heart attack death for younger women compared to men.

What is not clear is why heart attack is a greater threat to the lives of women than men. Researchers believe it is likely due to a combination of factors. For example, women are more likely than men to have other serious illnesses, many of which could add to the risk of mortality from heart disease. Also, younger women are statistically less likely to develop acute coronary syndromes (UA, AMI) than men. Although a postmenopausal woman’s risk eventually catches up to her male counterpart’s, doctors may be slower to diagnose and treat a condition they are less likely to expect. This problem could be compounded by the fact that diagnosing coronary heart disease can be more challenging in women than men. Chest pain, the classic symptom of heart attack in men, is often not a symptom in women. Indeed, far less is known about the early warning symptoms of heart attack in women compared to men.

With heart disease being the single largest killer of women in the United States, it is imperative that patients and their physicians take seriously the impact of acute coronary syndromes in this population. Until more research is done to better explain the reasons for these inconsistent outcomes between men and women, doctors should diagnose and treat acute coronary syndromes with equal zeal in all of their patients.