A recent study published by the American Heart Association shows that mortality rates are higher for women in Ohio who have a heart attack (myocardial infarction or MI). The reason for this is that women are less likely than men to present with classic findings of chest pain. We have long known that physician bias results in misdiagnosis of MIs in women. This study is concerning because it makes it more likely that a physician will misdiagnosis a woman having a heart attack.
All physicians are trained to use the so-called “differential method” to list all possible causes of a patient’s symptoms. Then, the physician must rule out those conditions on the list that do not fit. Of course, physicians are supposed to start by ruling out life threatening conditions first, like heart attack. They do this by taking a complete history, conducting a thorough physical exam and performing appropriate tests in a timely manner. When a condition cannot be ruled out, treatment must be started.
Unfortunately, physicians all too often bypass steps in the differential method and thereby put their patients at unnecessary risk of harm. Studies show that physicians frequently use “heuristics,” or short cuts in thinking, to jump to conclusions regarding their patients. Sometimes these heuristics are useful timesavers or help narrow down the differential. Other times, heuristics are just plain dangerous.
In the case of physicians missing MIs in women who do not present with chest pain, two dangerous heuritics are at work. First, there is a bias toward believing that heart disease is primarily a male condition. So, a woman presenting with symptoms of a heart attack may be underassessed for that condition. Second, if women are less likely to present with classic chest pain, MI may not be listed in the differential until it is too late.
Using the differential method properly, a physician must recognize that patients, irrespective of their sex, who present with risk factors and signs of MI other than chest pain, like shortness of breath, back pain or vital sign abnormalities, may have an MI. In other words, MI cannot be ruled out simply because the patient does not have chest pain, and therefore, must remain in the differential. Since it is a life-threatening condition, testing for that condition must be commenced urgently. Fortunately, the tests for MI are easy, quick and cheap — blood is drawn to assess for cardiac enzymes, and an EKG and chest xray are done to look for other telltale abnormalities. It is only by following the differential method, and not taking shortcuts, that women will be reliably diagnosed and treated for heart attacks.