CXC Chemokine Ligand 16 as a Prognostic Marker in Patients with Intermediate Coronary Artery Lesions: A 2-Year Follow-Up Study

There is no reliable way to identify the high-risk patients with intermediate coronary artery lesions (diameter stenosis 20%-70%) in early stage. Soluble CXC chemokine ligand 16 (CXCL16) is a newly discovered chemokine that can mediate inflammatory responses. It is released by proteolytic cleavage of its membrane-bound form, named scavenger receptor for phosphatidylserine and oxidized lipoprotein (SR-PSOX) that can promote the uptake of oxidized low-density lipoprotein cholesterol by macrophages. We have hypothesized that CXCL16 is an indicator of the prognosis of intermediate coronary artery lesions, and thus assessed the association between plasma CXCL16 concentrations and the 2-year prognosis in 616 patients with intermediate coronary artery lesions. The primary endpoint was a composite of all-cause death, non-fatal myocardial infarction, revascularization and angina pectoris requiring re-hospitalization. During the median follow-up time of 24 months, 69 events occurred. The plasma concentrations of CXCL16 (median 7712.88 pg/ml vs. 6792.43 pg/ml, P = 0.014) and high-sensitivity C-reactive protein (hs-CRP) (median 2.82 mg/L vs. 1.68 mg/L, P < 0.001) were higher in patients with events than patients without events. Cox hazard proportion analysis showed patients in upper CXCL16 quartile were more likely to suffer from adverse outcome than patients in lower quartile (RR = 1.271, P = 0.029, 95% CI: 1.025-1.577) after adjusting for sex, age, smoking, hypertension, diabetes, fat, dyslipidemia, hs-CRP, and medication use. In conclusion, plasma level of CXCL16 is an independent predictor of the prognosis of the patients with intermediate coronary lesions. Elevated plasma CXCL16 is associated with higher risk for these patients.