Introduction

The no-reflow phenomenon is a major complication in patients with acute coronary syndrome undergoing percutaneous coronary intervention, significantly impacting prognosis. Endothelial dysfunction and systemic inflammation are central to its pathogenesis.

Aim

This study aimed to evaluate the predictive value of the endothelial stress ratio – a novel composite index incorporating fibrinogen, albumin, C-reactive protein, and lymphocyte count – for the occurrence of the no-reflow phenomenon in patients with acute coronary syndrome.

Material and methods

This retrospective study included 1256 patients with acute coronary syndrome treated with percutaneous coronary intervention. Clinical and procedural data, including Killip class, presentation type, and angiographic findings such as infarct-related artery, multivessel disease, and pre-procedural Thrombolysis in Myocardial Infarction flow, were evaluated. The endothelial stress ratio was calculated using pre-procedural blood samples. To address multicollinearity, two separate multivariate logistic regression models were constructed: Model 1 included the fibrinogen-to-albumin ratio, while Model 2 evaluated the independent predictive value of the endothelial stress ratio alongside clinical variables.

Results

The no-reflow phenomenon occurred in 73 (5.8%) patients. Patients with no-reflow had significantly higher endothelial stress ratio values (138 (102–198) versus 72 (49–104), p < 0.001). In multivariate analysis, the endothelial stress ratio was the strongest independent predictor of no-reflow (Model 2, odds ratio: 1.48, 95% confidence interval: 1.21–1.82, p < 0.001). Receiver operating characteristic analysis demonstrated a strong discriminative performance, with an area under the curve of 0.82 (p < 0.001).

Conclusions

The endothelial stress ratio is a novel, independent biomarker for predicting no-reflow. Incorporating this ratio into pre-procedural assessment may help identify high-risk patients and guide therapeutic strategies.