Identification of Regional Wall Motion Abnormalities by Emergency Physicians in Acute Coronary Syndromes: Systematic Review and Meta-Analysis

Introduction: Chest pain accounts for approximately six million emergency department (ED) visits annually in the United States. Early detection of acute occlusive myocardial infarction (OMI) is challenging, especially in patients without classic ST-elevation on initial electrocardiography (ECG). Regional wall motion abnormalities (RWMA) often precede ECG changes and can be sensitive indicators of acute coronary occlusion on transthoracic echocardiography (TTE). However, the accuracy of emergency physician-performed TTE for RWMA detection has not been well defined. In this review we aim to determine how accurate emergency physicians are in detecting RWMAs. Methods: We conducted a systematic review of studies including adult ED patients who underwent cardiac ultrasound performed or interpreted by emergency physicians, with test characteristics compared to cardiology-performed or interpreted echocardiography as the reference standard. Primary outcomes were sensitivity and specificity for RWMA detection. Secondary outcomes included likelihood ratios, and area under the receiver-operator curve (AUC). Risk of bias was assessed using QUADAS-2, and evidence certainty was evaluated using GRADE methodology. Results: The search identified 2,463 studies, of which 32 underwent full-text review; nine studies including 1,191 participants from the US, Turkey, and Iran are included. Sonographers across studies ranged from medical students and residents to fellowship-trained and senior emergency physicians with varying levels of prior ultrasound and RWMA-specific training. Pooled sensitivity and specificity for RWMA detection were 86% (95% CI, 76-93%) and 85% (95% CI, 70-94%), respectively, with an AUC of 0.918. Pooled positive and negative likelihood ratios were 5.42 (95% CI, 2.51-11.68) and 0.17 (95% CI, 0.09-0.33), respectively. Four of the nine studies were judged to have a high risk of bias in at least one domain. Substantial heterogeneity was observed in the secondary univariate analyses (>80%). The overall certainty of evidence was moderate. Conclusion: Emergency physician-performed or interpreted cardiac ultrasound demonstrates high accuracy for detecting RWMAs compared with cardiology-performed or interpreted echocardiography. Although heterogeneity was observed across studies, the overall certainty of evidence was moderate. Structured training and standardized protocols may optimize diagnostic performance.