Predictive value of combined MHR and Lp(a) for in-stent restenosis in coronary heart disease patients: a study based on GEE model

Objective To investigate the associations of monocyte count, lipoprotein(a) [Lp(a)], and monocyte-to-HDL ratio (MHR) with in-stent restenosis (ISR) in coronary heart disease (CHD) patients after drug-eluting stent (DES) implantation, and to develop a predictive risk model. Methods This study enrolled 190 CHD patients who underwent DES implantation from 2019 to 2024. Based on 1-year coronary angiography, patients were divided into an ISR group ( n = 40) and a Non-ISR group ( n = 150). Baseline characteristics, laboratory markers, coronary lesions, and stent parameters were analyzed. Logistic regression and generalized estimating equation (GEE) models were used to identify independent predictors. ROC curves assessed the diagnostic performance. A risk score was constructed and its association with major adverse cardiovascular events (MACE) evaluated. Results Compared to the Non-ISR group, ISR patients had higher monocyte count, MHR, and Lp(a) levels (all P < 0.05), and more frequent left main and multivessel disease. Monocyte count (OR = 1.949), Lp(a) (OR = 1.22), and MHR (OR = 1.009) were independent risk factors for ISR. ROC analysis showed AUCs of 0.815, 0.672, and 0.726 for monocytes, Lp(a), and MHR, respectively. Combined detection of MHR and Lp(a) improved the AUC to 0.860. The risk score effectively stratified patients, with a higher MACE incidence in the high-risk group (35% vs. 10%). Conclusion Monocyte count, Lp(a), and MHR are closely linked to ISR in CHD patients post-DES. Combined assessment enhances risk prediction, offering a basis for early identification and personalized management to reduce restenosis and improve outcomes.