The novel inflammatory indices and coronary lesion severity in patients with non-ST-segment elevation acute coronary syndrome

Background: Non-ST-segment elevation acute coronary syndrome (NSTE-ACS) is a common form of acute coronary syndrome (ACS). Inflammation plays a key role in coronary atherosclerosis. This study aimed to evaluate the associations of the aggregate index of systemic inflammation (AISI), monocyte-to-high-density lipoprotein cholesterol ratio (MHR), and neutrophil-to-high-density lipoprotein cholesterol ratio (NHR) with coronary lesion severity in patients with NSTE-ACS, to facilitate early risk assessment in newly diagnosed cases.

Methods: This retrospective study enrolled 366 patients with newly diagnosed NSTE-ACS who underwent coronary angiography at Jiangnan University Medical Center between January 2024 and May 2025. Patients were stratified into two groups based on Gensini score: mild group (Gensini score <30, n=150) and severe group (Gensini score ≥30, n=216). Correlations between inflammatory indices and Gensini score were assessed using Spearman’s analysis. Separate multivariable logistic regression models were constructed to evaluate the associations of AISI, MHR, and NHR with higher coronary lesion burden. Receiver operating characteristic (ROC) analysis and incremental ROC analysis were performed to assess discriminatory ability.

Results: The severe group exhibited significantly elevated AISI, MHR, and NHR levels compared to the mild group (P<0.05), with all three parameters positively correlating with Gensini scores (P<0.05). In the separate multivariable logistic regression models, AISI was independently associated with severe coronary artery lesions [odds ratio (OR): 1.284, 95% confidence interval (CI): 1.177–1.419, P<0.001]. Similarly, MHR (OR: 1.503, 95% CI: 1.305–1.753, P<0.001) and NHR (OR: 1.525, 95% CI: 1.339–1.756, P<0.001) were also independently associated with higher lesion burden. AISI showed the highest single-marker area under the curve (AUC) for identifying severe coronary artery lesions (AUC =0.787, 95% CI: 0.737–0.838). In incremental ROC analysis, the addition of AISI, MHR, and NHR to the baseline clinical model significantly increased the AUC from 0.687 to 0.790, 0.754, and 0.779, respectively.

Conclusions: AISI, MHR, and NHR were independently associated with higher coronary lesion burden in patients with NSTE-ACS and improved the discriminatory ability of the baseline clinical model. Although the AISI-added model showed the highest numerical AUC, no clear superiority among the three indices was observed. These readily available inflammatory indices may serve as adjunctive markers for coronary lesion severity assessment in NSTE-ACS.