Diagnostic accuracy of 18-lead versus 12-lead electrocardiography in acute coronary syndrome: A systematic review and meta-analysis

Abstract

Objective

To evaluate the diagnostic accuracy and clinical impact of 18‑lead electrocardiography compared with conventional 12‑lead ECG in patients with suspected acute coronary syndromes (ACS).

Methods

A systematic review and meta-analysis were conducted by searching PubMed, Embase, Scopus, and the Cochrane Library from inception to August 2025. Eligible studies compared 18‑lead with 12‑lead ECG using angiography, biomarkers, or imaging as reference standards. Data were extracted to construct 2 × 2 tables where available, and pooled sensitivity, specificity, and risk ratios were calculated using random-effects models. Risk of bias was assessed with QUADAS-2, and certainty of evidence was graded with GRADE.

Results

Seven studies met the inclusion criteria, of which four provided extractable diagnostic accuracy data (n ≈ 535). Across studies, 18‑lead ECG significantly improved sensitivity for posterior myocardial infarction (≈80–85 % vs 55–65 % with 12‑lead) and right ventricular infarction (≈78 % vs 58 %) while preserving specificity (≈90 %). Pooled analysis demonstrated a 34 % relative improvement in diagnostic yield (RR 1.34, 95 % CI 1.18–1.55; p < 0.01). Approximately 10–15 % of patients initially classified as NSTEMI were reclassified as STEMI-equivalents using 18‑lead recordings. Evidence of earlier catheterization laboratory activation was noted in emergency department cohorts.

Conclusion

Eighteen‑lead ECG enhances detection of posterior and right ventricular infarctions without loss of specificity and supports earlier intervention. Broader clinical adoption and outcome-focused trials are warranted.