Association of red cell distribution width and platelet distribution width with angiographic severity of coronary artery disease in patients with stable angina: a cross-sectional study

Objective: To assess the associations of red cell distribution width-standard deviation (RDW-SD) and platelet distribution width (PDW) with angiographic coronary artery disease (CAD) severity, using the Gensini score, in adults undergoing coronary angiography for stable angina. Methods: This single-centre cross-sectional study recruited 65 consecutive adults who underwent coronary angiography for stable angina at Mosul Cardiac Centre, Iraq, between January and August 2025. A Gensini score ≥32 defined severe CAD. Clinical and laboratory measurements, including RDW-SD and PDW, were compared by severity. Spearman correlation, logistic regression and receiver operating characteristic (ROC) analyses were performed. Results: Severe CAD occurred in 29/65 patients (44.6%); 36 (55.4%) had mild-to-moderate disease. RDW-SD was higher in severe CAD (45.85 ± 6.36 fL) than in mild-to-moderate disease (42.41 ± 3.25 fL; p = 0.003). RDW-SD correlated with Gensini score (rs = 0.358; p = 0.003) and remained associated after adjustment (adjusted OR, 1.320 per unit; 95% CI, 1.055–1.651; p = 0.015). RDW-SD AUC was 0.710 (95% CI, 0.582–0.837). PDW did not differ (15.60 ± 1.50 vs 15.80 ± 1.30 fL; p = 0.452) and showed poor discrimination (AUC, 0.430). Severe CAD also had higher fasting glucose and white blood cell count. Conclusions: In this single-centre study of stable angina, RDW-SD was related to the severity of CAD as defined by Gensini but not PDW in this sample. The discrimination of RDW-SD was limited-to-moderate. The preliminary results of this study need to be confirmed in a larger population before use in the clinic.