Refining coronary artery disease detection: integrating left ventricular longitudinal strain and high-sensitivity C-reactive protein for risk stratification

Abstract Introduction Coronary angiography (CAG) is an invasive diagnostic procedure used to identify patients with coronary artery disease (CAD). The literature reports variability in the detection rates of obstructive CAD during elective coronary angiography. Given its invasive nature and the use of iodinated contrast, careful patient selection is essential to minimize procedural risks and potential complications. Purpose Our study aimed to analyze High-sensitivity C-reactive protein (hs-CRP) and echocardiographic parameters of left ventricular (LV) longitudinal strain as predictors of obstructive and non-obstructive CAD in patients undergoing elective CAG. Methods This cross-sectional observational study included 128 patients admitted for elective CAG at our tertiary medical center, all of whom had no prior diagnosis of CAD. Speckle Tracking Echocardiography and hs-CRP were assessed in all patients. Participants were categorized into two groups based on the presence of CAD and the degree of arterial obstruction. Patients with ≥50% stenosis were classified as having obstructive CAD, while those with 50% stenosis were categorized as having non-obstructive CAD. Statistical analysis was performed using Stata/BE 18. Results As shown in Table 1, LV global longitudinal strain (GLS) (-16.8%) demonstrated strong predictive value for obstructive CAD, with an area under the curve (AUC) of 0.720, balanced sensitivity (70%), and specificity (71.19%). In contrast, hs-CRP (cutoff: 1.13 mg/L) exhibited high sensitivity (90%) but low specificity (24.58%), suggesting its potential usefulness in ruling out disease rather than confirming it. For non-obstructive CAD, GLS (-18.3%) was the most robust predictor (AUC = 0.703), followed by apical three-chamber longitudinal strain (AP3L) (-18.1%) (AUC = 0.690). In contrast, hs-CRP (cutoff: 2.16 mg/L) had the weakest predictive value (AUC = 0.531), indicating it is not a reliable marker for non-obstructive CAD. Conclusions Our findings highlight LVGLS as a valuable tool for predicting both obstructive and non-obstructive CAD, reinforcing its role in refining risk assessment beyond traditional diagnostic methods. Given its ability to detect subtle myocardial dysfunction, LVGLS may also serve as a useful marker for identifying microvascular disease, which remains undetected by conventional CAG. In contrast, hs-CRP demonstrated high sensitivity but poor specificity, suggesting that while it is not a reliable confirmatory marker, a lower cutoff value of 1.13 mg/L may help exclude CAD with high negative predictive value. These findings emphasize the potential of combining echocardiographic strain imaging with inflammatory biomarkers to enhance patient selection and risk stratification, thereby reducing unnecessary invasive procedures.