Inflammation-Based C-Reactive Protein-to-Albumin Ratio for No-Reflow Prediction in STEMI

Background: The C-reactive protein/albumin ratio (CAR) has increasingly attracted attention as a reliable predictive marker in patients with acute myocardial infarction (AMI). Purpose: This study aimed to evaluate the predictive value of the CAR for no-reflow development. Methods: A total of 201 patients with STEMI who underwent PCI were included in the study. Admission laboratory tests included CRP, albumin, CK, CK-MB, troponin T, and other biochemical parameters. The CAR was calculated as CRP divided by albumin ×100, while the CUAR was calculated as the base-10 logarithm of CRP × UA divided by albumin. Patients were then divided into two groups based on CAR levels. Results: A total of 201 STEMI patients were included: 106 (52.7%) in the low-CAR group (≤48.4) and 95 (47.3%) in the high-CAR group (>48.4). Significant differences between groups were observed for smoking, albumin, cholesterol, CRP, CUAR, and TIMI flow grade ≤ 2. Logistic regression analysis identified albumin, cholesterol, CRP, BUN, uric acid, CK-MB, CAR, and CUAR as significant predictors of TIMI flow grade. A receiver operating characteristic (ROC) curve of CRP, albumin, CAR, and CUAR was used to plot the true positive rate against the false positive rate across various cut-off points; the area under the curve (AUC) was 0.87 (95% CI, 0.81–0.94, p < 0.0001) for CRP, 0.73 (95% CI, 0.65–0.81, p < 0.0001) for albumin, 0.9 (95% CI, 0.84–0.95, p < 0.0001) for the CAR, and 0.94 (95%, 0.89–0.99, p < 0.0001) for the CUAR. The cut-off values were 2.11 for the CUAR, 48.4 for the CAR, 18 for CRP, and 38 for albumin. Conclusions: The ratio of C-reactive protein to albumin (CAR) may serve as a reliable and clinically accessible marker associated with the no-reflow phenomenon in STEMI patients undergoing PCI. A defined CAR cut-off has been proposed to help stratify patients at increased risk of no-reflow.