Diagnostic accuracy of point-of-care cardiac ultrasound for acute coronary syndromes in patients presenting with chest pain to the emergency department: a single-center prospective study.

Background and importance: The diagnostic accuracy of focused cardiac ultrasound (FoCUS) performed in patients presenting to the emergency department (ED) with chest pain is currently unknown.

Objective: The objective of this study was to assess the diagnostic accuracy of regional wall motion abnormalities detected with FoCUS for non-ST-elevation acute coronary syndrome (NSTE-ACS) diagnosis.

Design: A Single-center prospective observational study conducted in 2022 in the ED of the University Hospital Careggi, Italy.

Setting and participants: Adult patients presenting to the ED with acute nontraumatic chest pain were enrolled, irrespective of the presence of previous regional wall motion abnormalities. Patients with ST-segment elevation myocardial infarctions and patients with hemodynamic instability were excluded. FoCUS was performed at presentation by a trained ED physician.

Outcome measures and analysis: The final diagnosis of NSTE-ACS vs. alternative diagnosis was adjudicated by an ED physician blinded to FoCUS results after a 30-day follow-up. To assess if regional wall motion abnormalities were an independent predictor of NSTE-ACS, a multivariable logistic regression model was built. Diagnostic performance measures were calculated. A sensitivity analysis considering only type-1 NSTEMIs (i.e. plaque rupture/thrombosis) was conducted.

Main results: Among 686 patients, NSTE-ACS was adjudicated in 106 (15.5%) patients, 67 of which were NSTEMIs. A total of 87 (12.7%) patients had regional wall motion abnormalities detected by FoCUS, which were an independent predictor of NSTE-ACS in the multivariable logistic regression analysis. Regional wall motion abnormalities had a sensitivity of 42.5% (33.0-51.9), a specificity of 92.8% (90.6-94.9), a negative predictive value of 89.8% (87.4-92.2), and a positive predictive value of 51.7% (41.2-62.2), for NSTE-ACS. Results were consistent in the sensitivity analysis.

Conclusions: In ED patients with chest pain and no ST elevation, the detection of regional wall motion abnormalities was a predictor of NSTE-ACS. Despite a high specificity, which indicated a possible role of FoCUS in the rule-in of NSTE-ACS, sensitivity was too low to allow a safe rule-out using FoCUS results alone.