Relationship of serum calprotectin, angiopoietin‑1, and angiopoietin‑2 levels with coronary collateral circulation in patients with stable coronary artery disease

Background: In patients with chronic stable coronary artery disease (CAD), well‑developed coronary collateral circulation (CCC) is known to reduce long‑term mortality. Aims: The objective of this study was to determine the relationship of serum calprotectin (S100A8 / S100A9), angiopoietin‑1 (Ang‑1) and angiopoietin‑2 (Ang‑2) concentrations with CCC in patients with stable CAD. Methods: This prospective cross‑sectional study included 147 patients with stable angina pectoris. The Cohen–Rentrop classification was used to assess CCC. Patients were divided into 2 groups: with poor CCC (Cohen–Rentrop score, 0–1; n = 79) and with good CCC (Cohen–Rentrop score, 2–3; n = 68). Serum calprotectin, Ang‑1, and Ang‑2 concentrations were compated between groups. Results: Compared with the group with good CCC, serum calprotectin and Ang‑1 levels were higher (P < 0.01 and P < 0.001, respectively), while serum Ang‑2 levels were lower (P < 0.01) in the poor‑CCC group. C‑reactive protein levels showed a moderate positive correlation with calprotectin levels (r = 0.359; P < 0.001). In a multivariate regression analysis, only calprotectin (P < 0.05) and Ang‑1 (P < 0.05) were found to be independent predictors of good and poor CCC. Conclusions: Our study showed that Ang‑2 levels were lower, while serum calprotectin and Ang‑1 levels were higher, in patients with stable CAD and poor CCC regardless of the complexity and severity of coronary arteriosclerosis. If these results are confirmed in future studies, calprotectin may be considered a useful biomarker for guiding anti‑ischemic treatment