The Predictive Value of Novel Inflammatory Markers for Silent Myocardial Ischemia in High-Risk Diabetic Patients: A Retrospective Cohort Study

Background: Silent myocardial ischemia (SMI) is a major cause of morbidity and mortality in patients with type 2 diabetes mellitus (T2DM), yet routine screening protocols remain suboptimal. Emerging evidence suggests that novel inflammatory ratios, such as the Neutrophil-to-Lymphocyte Ratio (NLR) and the Platelet-to-Lymphocyte Ratio (PLR), may serve as cost-effective surrogates for coronary artery disease burden. Objective: The objective of the present study was to assess the diagnostic accuracy of baseline neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) to predict the presence of stress myocardial ischemia (SMI) detected by stress echocardiography or myocardial perfusion imaging in high-risk diabetic patients. Methods: A retrospective cohort study was performed at King Hussein Medical Center, Royal Medical Services, Jordan. Adult patients (≥18 years) with type 2 diabetes mellitus screened for SMI from January 2021 to September 2025 were included. Data collected included demographic characteristics, glycemic controls (HbA1c), lipids and complete blood counts for calculating NLR/PLR. Patients were stratified into two groups according to the presence or absence of SMI on stress testing. Multivariate logistic regression identified independent predictors of SMI. ROC analysis evaluated the diagnostic accuracy of NLR and PLR. Results: Among 387 patients (mean age 62.4 ± 9.8 years, 54.2% male), SMI was detected in 98 patients (25.3%). Patients with SMI had significantly higher NLR (3.8 ± 2.1 vs. 2.4 ± 1.4, p<0.001) and PLR (142.6 ± 58.4 vs. 108.2 ± 42.6, p<0.001) compared to those without SMI. On multivariate analysis, independent predictors of SMI included: NLR ≥3.0 (OR=3.42, 95% CI: 2.18–5.36), PLR ≥130 (OR=2.84, 95% CI: 1.82–4.43), HbA1c ≥8.5% (OR=2.45, 95% CI: 1.56–3.85), duration of diabetes >10 years (OR=2.12, 95% CI: 1.34–3.36), and LDL ≥100 mg/dL (OR=1.78, 95% CI: 1.12–2.83). ROC analysis demonstrated that NLR (AUC=0.82, 95% CI: 0.78–0.86) and PLR (AUC=0.79, 95% CI: 0.74–0.84) had good discriminatory ability for SMI. A combined model incorporating NLR, PLR, HbA1c, and diabetes duration achieved excellent discrimination (AUC=0.88, 95% CI: 0.84–0.92). Conclusion: Baseline NLR and PLR are independent predictors of silent myocardial ischemia in high-risk diabetic patients and demonstrate good diagnostic accuracy. These simple, cost-effective inflammatory markers may serve as useful screening tools to identify diabetic patients who warrant further cardiovascular evaluation.