Abstract
BACKGROUND: Functionally significant coronary artery disease (CAD) leads to myocardial perfusion deficits and cardiac dysfunction. Quantitative flow ratio (QFR) allows accurate assessment of functional stenosis without the need for pressure wire or adenosine. Traditional transthoracic echocardiography (TTE) and speckle-tracking echocardiography (STE) are commonly used to evaluate myocardial structure and function. This study aimed to evaluate and compare the diagnostic value of TTE and STE in identifying functionally significant coronary stenosis. METHODS: A total of 112 hospitalized patients with suspected CAD underwent QFR assessment. Patients were divided into two groups based on QFR (QFR ≤0.8 and >0.8). TTE and STE were performed within 24 hours prior to coronary angiography. Logistic regression and receiver operating characteristic (ROC) curve analyses were used to evaluate the diagnostic performance of echocardiographic parameters. RESULTS: Compared to the QFR >0.8 group, patients in the QFR ≤0.8 group showed significantly higher interventricular septal thickness (IVS, P=0.007), posterior wall thickness (P=0.038), and left ventricular mass index (LVMI, P=0.006). Basal longitudinal strain (Basal LS) was significantly lower in the QFR ≤0.8 group (P=0.008). Multivariate logistic regression identified Basal LS as an independent predictor of functionally significant CAD [odds ratio (OR) =1.148, P=0.039]. ROC analysis revealed comparable diagnostic performance for Basal LS [area under the curve (AUC) =0.634, P=0.016], IVS (AUC =0.653, P=0.005), and LVMI (AUC =0.683, P=0.001), with no statistically significant difference among them (all P>0.05). CONCLUSIONS: Basal LS is independently associated with functionally significant CAD. However, its diagnostic efficacy is limited and comparable to structural parameters such as IVS and LVMI. Combining STE with other imaging modalities, such as myocardial contrast echocardiography, may improve diagnostic accuracy.