Copeptin: Limited Usefulness in Early Stroke Differentiation?

Area of Science:

• Neurology
• Biomarkers
• Emergency Medicine

Background:

• Diagnosing stroke in emergency settings presents significant challenges.
• Differentiating between ischemic stroke (IS), transient ischemic attack (TIA), and stroke mimics is crucial for timely and appropriate treatment.

Purpose of the Study:

• To evaluate the utility of copeptin as a biomarker for distinguishing IS, TIA, and stroke mimics.
• To assess copeptin levels in patients presenting with suspected stroke symptoms within 4.5 hours of onset.

Main Methods:

• Copeptin levels were measured in blood samples from 36 patients with suspected stroke.
• Final diagnoses were determined by vascular neurologists blinded to copeptin results.
• Diagnostic accuracy, sensitivity, and positive predictive value of copeptin for IS were calculated.

Main Results:

• Copeptin levels were higher in IS patients (19.1 pmol/L) compared to TIA patients (9.4 pmol/L).
• Stroke mimics exhibited a broad range of copeptin values (33.3 pmol/L).
• Copeptin showed a diagnostic accuracy of 63% for IS, with 80% sensitivity and 64% positive predictive value.

Conclusions:

• While copeptin levels were elevated in IS compared to TIA, their broad variability in stroke mimics restricts diagnostic utility.
• Copeptin may aid in differentiating IS from TIA but is less reliable for excluding stroke mimics.