Where do patients who are diagnosed with ACS obtain their health information? In decades past, such patients were frequently hospitalized and would receive education and counseling from physicians and nurses during their hospital stay. Unfortunately, structural changes in health care delivery have led to decreased lengths of hospital stay and increased use of outpatient facilities for cardiac diagnosis and treatment, which in turn have had a dramatic effect on the time available for the education of patients with ACS. In a recent study of the discharge education given to heart failure patients, only 54% received the instructions comprising the Joint Commission (TJC) process-of-care measure.17
This percentage was achieved given the impetus of TJC standards and it is likely that the percentage for non-mandated discharge education is much lower. Thus, there is an increasing onus on physicians to insure that patients who are at high risk for a future AMI are knowledgeable about ACS symptom presentation and that these patients understand the importance of responding quickly to cardiac symptoms to optimize survival and treatment outcomes.
Our study is the first large-scale, international study conducted to assess the knowledge of patients with documented ACS about their disease and its symptoms. Given that individuals with coronary heart disease have a five to seven times greater risk of AMI or death than the general population,18
we also assessed their sense of perceived risk for a future AMI with the assumption that a heightened sense of perceived risk may contribute to quicker action to seek treatment at the onset of symptoms and reduced prehospital delay time. Physicians and other health professionals might appropriately believe that this group of high-risk patients will be knowledgeable about the actions to take in the face of new ACS symptoms and will act quickly to access the emergency medical system. However, numerous investigators have documented that patients who have experienced an AMI in the past have prehospital delay times that are not significantly different than patients with no history of AMI.7,19
Given the relatively low level of knowledge in this high-risk population, it is perhaps not surprising that persons with a previous history of AMI are not more likely to recognize AMI symptoms and seek treatment early when compared to previously healthy individuals. 19
Our findings about what patients with documented heart disease know about the symptoms of AMI and appropriate actions to take, as well as their perceived risk of vulnerability for a future AMI, provide important insights into this phenomenon that is counterintuitive for clinicians. Their knowledge about heart disease was relatively low and perceptions of personal risk lower than expected in this high-risk group with a history of heart disease. In an attempt to identify which patients in clinical practice may need extra attention by physicians in medical follow-up visits, we identified characteristics associated with higher and lower levels of knowledge about heart diseases. Gender, age and education were all significant predictors of knowledge, with male sex, older age, and less formal education associated with less knowledge.
The findings about gender were particularly surprising, because women have often underestimated their risk for heart disease in years past20,21
and have had longer pre-hospital delay times than men,22,23
suggesting a lack of knowledge about AMI symptoms or a lack of appreciation for the importance of heart disease as a cause of death in women. In recent large community samples of healthy individuals, gender made no difference in knowledge about heart disease and its symptoms,24,25
findings that are in direct contrast to the findings in the current study. In our study that included only people with known coronary artery disease, we found that women were more knowledgeable than men about ACS symptoms and more likely to see themselves at higher risk than age-matched healthy controls.
The findings related to gender differences suggest that physician counseling of female patients, coupled with a number of community-based, public education programs conducted over the past decade by the federal government and organizations such as the American Heart Association and the National Heart Foundation of Australia have had a positive effect. Some of the campaigns such as the American Heart Association’s “Go Red” and the National Heart, Lung, and Blood Institute's "Heart Truth" campaign have focused specifically on women to alert them to their risk for heart disease, and our findings support recent evidence that such campaigns have had a positive effect.21
We found that women were more likely than men to identify less well appreciated symptoms of AMI and were more likely to identify the appropriate actions to take in the face of new AMI symptoms. Compared to men, women were significantly more likely to know about the possibility of reperfusion therapy and the need to call the Emergency Medical System (EMS) rather than drive themselves to the hospital. Other investigators have found that the majority of information for women about ACS symptoms comes from the media,25
suggesting that the recent media campaigns have been successful in raising women’s level of knowledge and sense of perceived risk.
Two other clinical variables were associated with higher levels of knowledge; namely, being under the care of a cardiologist and having attended a cardiac rehabilitation program. Both underscore the importance of specialty care for patients with heart disease, findings that are well supported in previous studies of clinical outcomes. For example, patients with heart disease who are seen by cardiologists rather than generalists for their care are more likely to receive care recommended in clinical guidelines and more likely to have positive clinical outcomes.26
Although not yet documented, a perceived sense of vulnerability to a future AMI may be helpful in getting patients to pay attention to cardiac symptoms when they occur and to seek treatment promptly by calling EMS. Patients were more likely to feel at appropriately high risk if they were older, a current smoker, and had a history of AMI, angioplasty or hypercholesterolemia, all of them highly accurate perceptions given epidemiological data about cardiac risk factors. Higher levels of knowledge were also associated with higher levels of perceived risk, suggesting that instruction about ACS symptoms and steps to take in an emergency may influence patients’ understanding of their vulnerability for a future heart attack. This inverse relationship of knowledge and perceived risk suggests that the lower levels of knowledge about ACS documented in men compared to women underscores the need for continuing reinforcement of the information in physician-patient encounters. A sense of perceived risk or vulnerability may decrease prehospital delay to treatment, although this association awaits further study.
In summary, knowledge about ACS symptoms and correct actions to take in seeking care is required for appropriate self care. Physicians can identify patients who are less likely to have necessary knowledge and an appreciation of their high risk status and provide extra education and counseling. Our findings suggest that men, the elderly, those with low levels of education and those who have not attended a cardiac rehabilitation program are more likely to require special efforts during medical office visits to review symptoms of AMI and to learn the appropriate actions to take in the face of new symptoms of ACS.