Abstract & Commentary
Source: Marsan RJ, et al. Evaluation of a clinical decision rule for young adult patients with chest pain. Acad Emerg Med 2005;12:2632.
The authors developed a clinical decision rule for adult (younger than 40 years) chest pain patients, minimizing the risk of 30-day adverse cardiovascular (CV) events. Slightly more than 1000 patients ages 2439 years who received electrocardiograms (ECG) for chest pain during a 33-month period met criteria for enrollment; cocaine users were excluded. The main outcome was 30-day adverse CV events (e.g., death, acute myocardial infarction, percutaneous intervention, and coronary artery bypass graft); 30-day follow-up was done by telephone. The majority of patients were female (61%) and African American (73%). Overall, the risks of acute coronary syndrome (ACS) and 30-day adverse CV events were 5.4% and 2.2%, respectively. However, for the patients with no cardiac history and no cardiac risk factors, the risk of ACS and 30-day adverse CV event was 1.8%. Furthermore, in patients with no cardiac history and a normal ECG, the risk was reduced to 1.3%. Finally, patients with no cardiac history, no cardiac risk factors, and a normal ECG had a risk of 1.0%. A modified clinical decision rule using the above factors plus serum markers for cardiac ischemia, found that in young adult patients: 1) without a known cardiac history, 2) with either no classic cardiac risk factors or a normal ECG, and 3) initially normal cardiac marker studies, the risk of ACS also was extremely low (0.14%); there were no adverse CV events at 30-day follow-up (95% CI, 0.1% to 0.2%).
Commentary by Richard Hamilton, MD, FAAEM, ABMT
There is a great deal of wisdom in the approach the authors take to our daily confrontation with low-risk chest pain patients — especially in the young. Simply put, their research takes the position that it may be easier to determine which patients seemingly never have an ACS, rather than to ascertain which patients are more likely to have it. As I often remind my exasperated residents, you could admit every single patient with chest pain and still miss a myocardial infarction; some patients with ACS, especially the elderly, present with other complaints, such as dyspnea. The more enlightened approach is take each patient and combine the information from the history and physical examination and the data from the ECG and cardiac markers to stratify and manage the risk—not always resulting in an admission. A far cry from the day when some ED physicians were compelled to admit anyone they had tested for CK-MB elevation, under the adage, "you can’t rule out an MI with one set of enzymes." In fact, the authors present a very convincing argument that you can—but only if you carefully select and screen your population, increasing the prior probability that your approach will be successful. That also reveals the only real flaw in this paper: The population was overwhelmingly female and African American. To ascertain the validity of the approach, it will be necessary to repeat the study in other demographically diverse populations. Until then, the advocated concept of risk stratification, with a more liberal approach to the outpatient workup in the low probability patient age range 25 to 40 years, is an intelligent and acceptable, if not entirely proven, approach.
Dr. Hamilton, Associate Professor of Emergency Medicine and Residency Program Director, Department of Emergency Medicine, Drexel University College of Medicine, Philadelphia, PA, is on the Editorial Board of Emergency Medicine Alert.