Acute coronary syndrome (ACS) is an umbrella term used to cover a variety of conditions that share a common factor—dangerously insufficient blood supply to the heart. When the blood supply to the heart is impaired, a person may experience angina (chest pain), a heart attack , or possibly death. Many patients with coronary heart disease have stable angina, which usually responds promptly to rest or medications. In patients with ACS, however, the situation is more unstable, and they require prompt medical attention to increase their chances of survival.

The most common symptom of ACS is chest pain. But, not all people who have ACS experience chest pain. In a study published in the August 2004 issue of Chest , researchers looked at the people who had ACSs and did not experience chest pain, but experienced other symptoms, and compared their treatment and outcomes to those who did experience chest pain.

About the study

To identify patients for this study, researchers used the Global Registry of Acute Coronary Events (GRACE), which is a large multinational registry of patients who have been hospitalized with ACS. In GRACE, the dominant symptom that a patient presented with was captured in the medical record. In a typical presentation, the patient experienced chest pain; in an atypical presentation, chest pain was not reported as a symptom.

Using the registry, the researchers identified almost 21,000 patients who were admitted to the hospital with ACSs over a three-year period. Of this group, 1,763 or 8.4% had atypical presentation. The dominant symptoms in patients with an atypical presentation were:

  • Difficulty breathing (dyspnea): 49.3%
  • Excessive sweating (diaphoresis): 26.2%
  • Nausea or vomiting: 24.3%
  • Fainting (Syncope): 19.1%

Interestingly, the patients with atypical symptoms were more likely to be older women who had a history of hypertension, diabetes, or heart failure.

The findings

The researchers found that almost one in every four people who presented to the hospital with atypical presentation (no chest pain) were misdiagnosed. Of the people with an atypical presentation, 23.8% were given an incorrect diagnosis compared with 2.4% of those with a typical presentation (chest pain).

More importantly, people without chest pain were three times as likely to die compared with those with chest pain—13% of patients with atypical symptoms died compared with 4.3% of patients with typical symptoms. This greater risk of dying was seen for all atypical symptoms except excessive sweating.

In addition, the atypical symptom group was more likely to experience heart failure, dangerously low blood pressure, disturbed heart rhythmms, and renal failure. Lastly, people who did not have chest pains were less likely to receive the appropriate medications or medical interventions compared with the group who experienced chest pains.

How does this affect you?

The study’s authors suggest that a possible limitation of the study may be due to the fact that the GRACE data is extracted from medical records, which could make it subject to second-hand interpretation or error. Even still, this study’s findings are rather startling. This alarming gap in treatment and outcomes between people experiencing ACS who have chest pain and those who do not can be closed.

Educating emergency department and coronary care personal about this study’s finding is an important step. But, educating yourself is the first step—especially if you are in the group more likely to present with atypical symptoms (older individual with hypertension, diabetes, or heart failure). Be aware of what is considered an atypical symptom for ACS: shortness of breath, excessive sweating, nausea and vomiting, lightheadedness, or fainting. And, if you are experiencing any of these symptoms, tell your doctor that you are concerned about ACS.