Fragmented QRS on Baseline Electrocardiography Predicts Anatomically Significant Stenosis in Patients With Intermediate Coronary Lesions on Coronary Computed Tomography Angiography

Background: Intermediate-grade stenosis (40–70%) on coronary computed tomography angiography (CCTA) often presents diagnostic uncertainty regarding the necessity of invasive coronary angiography (ICA). Although fragmented QRS (fQRS) on electrocardiography (ECG) indicates myocardial scarring and ischemia, its predictive value remains unclear in this specific cohort. We investigated the association between baseline fQRS and anatomically severe stenosis (≥ 70%) confirmed by ICA. Methods: This study retrospectively evaluated 200 patients with CCTA-detected intermediate stenosis who underwent subsequent ICA. Patients were stratified based on angiographic findings into severe stenosis (≥ 70%, n = 89) and non-severe stenosis (< 70%, n = 111) groups. Standard 12-lead ECGs were analyzed, and independent predictors were determined using binary logistic regression and receiver operating characteristic (ROC) curves. Results: The prevalence of fQRS was significantly higher in the severe stenosis group (65.2% vs. 16.2%, P < 0.001). Diabetes mellitus (36.0% vs. 22.5%, P = 0.036), hyperlipidemia (53.9% vs. 34.2%, P = 0.005), and smoking (60.7% vs. 32.4%, P < 0.001) were also more prevalent among patients with severe lesions. Multivariate analysis identified male gender (odds ratio (OR): 4.167, 95% confidence interval (CI): 1.798–9.655, P = 0.001), hyperlipidemia (OR: 2.342, 95% CI: 1.106–4.959, P = 0.026), and the presence of fQRS (OR: 5.814, 95% CI: 2.478–13.645, P < 0.001) as independent predictors of severe stenosis. ROC analysis demonstrated moderate diagnostic performance for fQRS (area under the curve (AUC): 0.745, 95% CI: 0.673–0.816, P < 0.001), yielding a sensitivity of 65.2% and a specificity of 83.8%. Conclusion: The presence of fQRS is strongly and independently associated with anatomically severe stenosis in patients with intermediate lesions on CCTA. Incorporating baseline fQRS evaluation may help refine clinical decision-making and narrow the diagnostic “gray zone.”