• 
• 

Three Part Question

In [adult patients with chest pain and possible acute coronary syndrome] what is the [diagnostic utility] of [routine chest radiographs]?

Clinical Scenario

The patient is a 52-year-old male with history of hypertension who presents to the emergency department (ED) with complaints of chest pain that started 1 hour prior to arrival. On arrival to the ED, he appears comfortable with stable vital signs, and has a normal physical exam. His pain is reported as mild, sharp and substernal, non-radiating, and worse with certain movements but not exertion. His pain resolves after 324 mg chewable aspirin and a lidocaine patch. His lab workup and elecrocardiogram are normal. The patient has a heart score of 2. You consider ordering a chest x-ray (CXR) prior to discharging the patient.

Search Strategy

Medline 1966-08/21 using PubMed, Cochrane Library (2021), and Embase
[(emergency medical services OR emergency department OR emergency services) AND (chest pain/diagnostic imaging OR heart diseases/diagnostic imaging OR acute coronary syndrome/diagnostic imaging)]

Search Outcome

51 studies were identified; three studies addressed the clinical question.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Poku J, et. al. Sept 2012 USA	Patients over 24 years of age with a primary complaint of chest pain and possible acute coronary syndrome (ACS)	Prospective validation of clinical decision rule (CDR)	Diagnostic accuracy of a CDR for chest radiography	Sensitivity was 100% and specificity was 11.5%; positive predictive value was 6.7%	Single center study, small sample size, study did not determine when chest radiograph was used to narrow differential diagnosis
Goldschlager R, et al. March 2014 USA	Patients over the age of 18 presenting with chest pain who had a CXR and troponin level ordered	Retrospective cohort	Diagnostic accuracy of Canadian ACS guidelines for appropriate CXR use	Sensitivity of 80% and a specificity of 50%; positive predictive value of 18%	Retrospective study; small sample size
Ng JJ, et al. Dec 2008 USA	Adult patients with suspected ACS	Retrospective cohort	Proportion of patients who had an abnormal chest radiograph	130 of the 158 patients (82%) had CXR	Retrospective study; small sample size; discrepancy between the ED physician and radiologist reports
			Proportion of radiographs that changed management	40 (31%) of which had some abnormality; only 3 results altered management

Comment(s)

Acute coronary syndrome (ACS) account for a significant number of U.S. ED visits annually. The diagnostic evaluation typically includes laboratory investigation, electrocardiogram, and a CXR. The utility of the CXR in ACS work-up has been researched; rarely do the results yield significant results or alter management of the patient. Previous studies suggest that between 20-30% of patients with chest pain have abnormal chest radiographs, but these radiographic abnormalities lead to a change in management in only 2-3%. There is no current universal clinical decision rule regarding when to order a CXR in the setting of ACS chest pain. Current guidelines that attempt to reduce the number of CXRs performed do so at the expense of missing significant CXR findings in 2-3% of patients. There is room for further research in this area to better establish which patient population and/or risk factors should prompt CXR to be included in the chest pain workup.

Clinical Bottom Line

Current decision rules and ACS guidelines have the potential to reduce the numbers of unnecessary CXRs performed in ACS work-up. However, this would come at the expense of missing significant CXR findings in 2-3% of patients.

References

1. Poku J, Bellamkonda-Athmaram V, Bellolio M, Nestler D, Stiell I, Hess E. Failure of prospective validation and derivation of a refined clinical decision rule for chest radiography in emergency department patients with chest pain and possible acute coronary syndrome Acad Emerg Med 2012;19:1004–1010.
2. Goldschlager R, Roth H, Solomon J, Robson S, Green J, Green S, Spanger M, Gunn R, Cameron P. Validation of a clinical decision rule: Chest X-ray in patients with chest pain and possible acute coronary syndrome. Emerg Radiol 2014 Aug;21(4):367-372
3. Ng JJ, Taylor DM. Routine chest radiography in uncomplicated suspected acute coronary syndrome rarely yields significant pathology Emerg Med J 2008 Dec;25(12):807-810