Systemic immune-inflammation index predicts the severity of coronary stenosis in patients with coronary heart disease.

Background: Coronary atherosclerosis is a systemic chronic inflammatory disease with variable occurrence and progression. Some laboratory parameters, such as the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and C-reactive protein (CRP) level, are used to evaluate the degree of inflammation and the severity of coronary artery disease (CAD). The neutrophil*platelet/lymphocyte is a novel systemic immune-inflammation index (SII), and its relationship with the development and severity of CAD is unclear.

Objective: To investigate the association between the SII and the severity of CAD.

Methods: Three-hundred and ninety-five patients who underwent coronary angiography were enrolled; among whom, 285 patients were included in the CAD group and 110 patients were included in the non-CAD group according to the WHO guidelines. Patients with CAD were further divided according to the Gensini score into the severe coronary stenosis group and the mild coronary stenosis group. The SII was calculated using the following formula: neutrophil*platelet/lymphocyte.

Results: When the cutoff value of the SII was set at 439.44, the predictive power of CAD was the highest, with a sensitivity and specificity of 64.6 and 68.2%, respectively. When the cutoff value of the SII was set at 652.83, the predictive power of severe coronary stenosis was the highest, with a sensitivity and specificity of 71.0 and 86.0%, respectively. The area under the curve of the SII in predicting severe coronary stenosis was greater than that of the NLR, PLR and CRP level.

Conclusion: The SII is an independent risk factor for the occurrence and severity of CAD.