Stop Waiting on That CXR for Heart Failure

September 8, 2021

Written by Megan Hilbert

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In older adults (> 50 years old) presenting with shortness of breath, point-of-care lung ultrasound was more sensitive in making the diagnosis of acute heart failure as compared to a radiologist-read CXR.

Why does this matter?
Shortness of breath is a common presenting chief complaint. Older individuals are particularly prone to this complaint given a myriad of underlying conditions including COPD and heart failure. In the undifferentiated patient, making the most accurate diagnosis is important in order to implement appropriate treatment in a timely manner.

Pull out that POCUS for dyspnea!
This article was a cohort study that reviewed the final diagnoses of older individuals who presented to the ED for evaluation of dyspnea. It sought to clarify the performance of lung ultrasound as compared to CXR to identify acute heart failure, as opposed to initial presumed diagnosis of COPD exacerbation. An ultrasound positive for pulmonary edema (and presumed heart failure) was defined as at least three B-lines in two zones using an eight zone technique.

While this study has its limitations – including small sample size (81) and high prevalence of pre-existing heart failure (35.8%) – it demonstrated a statistically significant increase in sensitivity (92.5%; 95%CI 83.4-97.5%) of identifying acute heart failure exacerbation with use of lung ultrasound over CXR (63.6%). Ultrasound did not, however, demonstrate statistically significant increase in specificity. These findings are consistent with prior studies and are not inherently ground breaking, but do highlight the importance of early use of ultrasound in identification of acute heart failure in your undifferentiated dyspneic patient. So stop waiting on that CXR and pick up a probe!

Source
Diagnostic Accuracy of Lung Point-Of-Care Ultrasonography for Acute Heart Failure Compared With Chest X-Ray Study Among Dyspneic Older Patients in the Emergency Department. J Emerg Med. 2021 Aug;61(2):161-168. doi: 10.1016/j.jemermed.2021.02.019. Epub 2021 Mar 29.