The following is a summary of “FOCUS may detect wall motion abnormalities in patients with ACS,” published in the July 2023 issue of Emergency Medicine by Bracey et al.

Approximately 6 million visits to the Emergency Department (ED) are attributed to chest pain. The electrocardiogram (ECG) is the primary diagnostic tool for identifying acute coronary syndrome (ACS). It is used to screen for electrocardiographic findings representing acute coronary occlusion. It is known that ischemia caused by an acutely occluded coronary artery produces a wall motion abnormality that can be visualized by echocardiogram; however, emergency physician-performed focused cardiac ultrasound (FOCUS) does not currently play a formal role in the diagnosis of OMI within the emergency department. Before undergoing cardiac catheterization or formal echocardiography, the researchers attempted to define the characteristics of FOCUS performed by emergency physicians with varying levels of training in identifying RWMA in patients presenting to the emergency department with a high suspicion of ACS. 

In addition, they investigated whether RWMA was linked to OMI in these patients. They conducted a structured retrospective review of adult patients with suspected ACS who presented to a large academic tertiary care center between July 1, 2019, and October 24, 2020. Patients were included if they underwent FOCUS in the ED during the time mentioned above period for suspected ACS in search of RWMA. FOCUS images were stored and accessible via their middleware software. The primary outcome was FOCUS’s accuracy, sensitivity, and specificity compared to conventional echocardiography in detecting RWMA. Secondary outcomes included the sensitivity of FOCUS compared to formal echocardiography for detecting RWMA in patients with and without cardiac catheterization-proven OMI and the sensitivity and specificity of FOCUS operators based on training. 

The sensitivity of FOCUS for RWMA performed by emergency physicians was 94% (95% CI, 82–98), the specificity was 35% (95% CI, 15–61), and the overall accuracy was 78% (95% CI, 66–87). About 82% of all subjects underwent urgent or emergency coronary angiography, with 71% suffering from OMI at the time of the procedure. FOCUS identified RWMA in 87% of coronary angiography-confirmed OMI patients. Residents (PGY-1 – PGY-3) (n = 31) had a sensitivity of 86% (95% CI, 64–96), a specificity of 56% (95% CI, 23–85%), and an accuracy of 77% (95% CI, 58–90%) when detecting RWMA. Fellows and attendings in emergency ultrasound (n = 34) were able to see RWMA with a sensitivity of 85% (95% CI, 64–95%), a specificity of 75% (95% CI, 36–96%), and an accuracy of 82% (95% CI, 65–93%). Their retrospective study concludes that FOCUS performed by emergency physicians can be used to detect RWMA in patients with a high risk for acute coronary syndrome. This may be most useful in patients presenting without STEMI, with equivocal ECG. Still, the clinician is deeply concerned about OMI, in which RWMA may result in urgent cath lab activation, although further investigation is required. In such cases, the presence of RWMA may help establish OMI as a cause; however, the absence of RWMA should rule out OMI. Additional research is required to corroborate these results.

Source: sciencedirect.com/science/article/abs/pii/S0735675723001717