Albumin-based inflammatory-nutritional indices and early neurological deterioration in patients with branch atheromatous disease: a retrospective cohort study

Introduction Early neurological deterioration (END) is a frequent and clinically relevant complication of branch atheromatous disease (BAD); however, it remains uncertain whether readily available albumin-based inflammatory-nutritional indices can help identify patients at higher risk. Methods In this retrospective cohort study, we examined associations between neutrophil percentage-to-albumin ratio (NPAR), prognostic nutritional index (PNI), and controlling nutritional status (CONUT) score with END among consecutive patients with BAD admitted to the China–Japan Union Hospital of Jilin University between January 2020 and October 2025. We defined END as an increase of ≥2 points in the total National Institutes of Health Stroke Scale score or ≥1 point in the motor score within 7 days after symptom onset. Associations were examined using logistic regression. We also assessed discrimination, calibration, exploratory net benefit, subgroup consistency, and possible nonlinearity. Results Among 338 patients, 61 (18.0%) developed END. In the primary multivariable model, each 0.1-unit increase in NPAR was associated with higher odds of END [odds ratio (OR) = 1.41, 95% confidence interval (CI): 1.23–1.61, p < 0.001], whereas higher PNI was associated with lower END risk (OR = 0.90, 95% CI: 0.84–0.97, p = 0.004). A higher CONUT score was also associated with greater END risk (OR = 1.28, 95% CI: 1.04–1.57, p = 0.020). NPAR showed the numerically highest area under the curve (AUC) among the three indices (AUC = 0.697, 95% CI: 0.620–0.773). A clinical model incorporating baseline NIHSS score, age, and systolic blood pressure had an apparent AUC of 0.608, compared with 0.731 after adding NPAR; bootstrap optimism-corrected AUCs were 0.582 and 0.710, respectively. Discussion Albumin-based inflammatory-nutritional indices, particularly NPAR, were associated with END in patients with BAD. NPAR remained associated with END after excluding first END within 24 h after admission and cases with unknown END timing. Prospective external validation is necessary prior to routine clinical use.