Association of Platelet–Albumin–Bilirubin and Albumin–Bilirubin Scores with Angiographic No-Reflow in Patients with ST-Segment Elevation Myocardial Infarction Undergoing Primary PCI

Background: The platelet–albumin–bilirubin (PALBI) and albumin–bilirubin (ALBI) scores integrate routinely available laboratory parameters with potential relevance to microvascular injury. We investigated their associations with angiographic no-reflow and incremental predictive value in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). Methods: This retrospective, single-center study included 1539 consecutive patients with STEMI undergoing primary PCI. No-reflow was defined by final TIMI flow < 3 and/or myocardial blush grade 0–1 in the absence of a mechanical cause. Associations of PALBI and ALBI with no-reflow were assessed using multivariable logistic regression. Discrimination, calibration, reclassification, internal bootstrap validation, and restricted cubic spline analyses were performed. Results: No-reflow occurred in 146 patients (9.5%). Both PALBI (adjusted odds ratio [aOR] per 0.1-point increase, 1.315; 95% confidence interval [CI], 1.228–1.408; p < 0.001) and ALBI (aOR, 1.165; 95% CI, 1.115–1.218; p < 0.001) were independently associated with no-reflow. PALBI showed greater discrimination than ALBI (AUC, 0.722 vs. 0.681; DeLong p = 0.018). Adding PALBI to the clinical model increased the AUC from 0.688 to 0.785 (ΔAUC = 0.098; p = 0.001), with significant NRI (0.777) and IDI (0.102), and improved the Brier score from 0.083 to 0.073. The optimism-corrected AUC was 0.762. PALBI demonstrated a non-linear association with no-reflow (p for non-linearity <0.001), whereas ALBI showed a predominantly linear association. Conclusions: Higher PALBI and ALBI scores were independently associated with angiographic no-reflow after primary PCI in STEMI. PALBI demonstrated stronger discrimination and incremental predictive performance; however, external validation and prospective evaluation are required to determine its potential clinical utility.