Admission CALLY Index and Angiographic No-Reflow After Primary PCI in a Retrospective STEMI Cohort

Background/Objectives: The CALLY index draws on three admission tests—C-reactive protein, albumin, and lymphocyte count. We investigated whether it was associated with angiographic no-reflow after primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI). Methods: We reviewed 1245 patients treated at one center between January 2024 and January 2026. Logistic regression accounted for clinical risk factors, baseline Thrombolysis in Myocardial Infarction (TIMI) flow, culprit artery, thrombus grade 5, Killip class at the start of PCI, and door-to-balloon time. We also tested alternative endpoint definitions, assessed influential observations, and compared correlated receiver operating characteristic (ROC) curves. Results: No-reflow occurred in 206 patients (16.5%). CALLY was lower in this group than in the reflow group (median 1.11 [0.39–1.92] vs. 1.33 [0.73–2.11]). Each one-unit increase in ln(CALLY) was associated with lower odds of no-reflow after adjustment (odds ratio [OR] 0.800, 95% confidence interval [CI] 0.693–0.923; p = 0.0023). The association remained when the endpoint was limited to impaired final angiographic reperfusion (OR 0.832, 0.717–0.965; p = 0.015). Discrimination by CALLY alone was poor (area under the curve [AUC] 0.578, 0.534–0.623); it was not significantly better than its components or the other indices studied. At a displayed threshold of ≤0.905, positive and negative predictive values were 22.8% and 86.8%. The association weakened after removal of the upper and lower 1% of values (p = 0.063). Conclusions: Admission CALLY was associated with recorded angiographic no-reflow, even after broader adjustment. Its weak discrimination and small incremental contribution, however, do not support use for individual risk classification without further study.