The C-reactive protein–albumin–lymphocyte index is associated with coronary collateral circulation in patients with chronic total occlusion

OBJECTIVE: Well-developed coronary collateral circulation (CCC) protects the myocardium from ischemia, but its development varies among individuals. The C-reactive protein-albumin-lymphocyte (CALLY) index is a composite marker of nutritional and inflammatory status. This study evaluated its association with well-developed CCC in patients with chronic total occlusion (CTO). METHODS: We included 369 patients with stable angina pectoris and CTO in at least one major epicardial coronary artery. The CALLY index was calculated from serum albumin, lymphocyte, and C-reactive protein levels. Patients were classified as having poor CCC (Rentrop 0-1, n = 140) or good CCC (Rentrop 2-3, n = 229). RESULTS: Patients with good CCC had higher CALLY index values than those with poor CCC [3.13 (interquartile range: 1.92-5.01) vs. 1.89 (1.17-2.66)]. The CALLY index showed moderate discrimination for good CCC [area under the receiver operating characteristic curve (AUC): 0.704, cutoff: 2.23, sensitivity: 64.2%, specificity: 65.7%]. In multivariable analysis, CALLY was independently associated with good CCC [odds ratio: 1.617, 95% confidence interval (CI): 1.374-1.902]. Adding CALLY to the baseline clinical model increased the AUC from 0.666 (95% CI: 0.609-0.723) to 0.761 (95% CI: 0.712-0.810; ΔAUC = 0.095; DeLong P < 0.001). CALLY also improved discrimination (integrated discrimination improvement: 0.120, 95% CI: 0.070-0.179, P < 0.001; continuous net reclassification improvement: 0.107, 95% CI: 0.004-0.229; P = 0.030). CONCLUSION: CALLY was independently associated with well-developed CCC and showed the highest discriminative performance among the evaluated inflammatory and nutritional indices. Its addition to the clinical model significantly improved discrimination, suggesting potential value in assessing CCC in patients with CTO.