Development and internal validation of a parsimonious model for neurological deterioration at 48 h after endovascular thrombectomy

The incremental value of routine admission measurements for predicting early neurological deterioration after endovascular thrombectomy (EVT) remains unclear.

This retrospective single-center reanalysis used a 2020-2022 registry. END48 was defined as an increase of at least 4 National Institutes of Health Stroke Scale (NIHSS) points from admission to the fixed 48-h postoperative assessment. The conservative primary cohort excluded an unresolved longitudinal data segment. A revision-stage locked five-predictor logistic regression model included admission NIHSS scores, age, glucose levels, white blood cell count, and ln triglyceride value, with the NIHSS-only model serving as the comparator. Internal validation used 1,000 bootstrap samples and paired nested intervals of 1,000 outer × 100 inner samples.

Of the 253 records representing 251 unique patients, 214 adults entered the primary cohort; 51 (23.8%) had END48. The primary model had an apparent area under the curve (AUC) of 0.651 and an optimism-corrected AUC of 0.601 (0.511 to 0.723). The corrected AUC difference vs. the NIHSS-only model was 0.038 (-0.025 to 0.171). The corrected Brier score was 0.180, compared to a prevalence-only reference of 0.182, resulting in a Brier skill score of 0.9%. The corrected primary calibration slope was 0.731 (0.519 to 0.892). Incremental net benefit was -0.015, 0.036, and 0.013 at 10%, 20%, and 30% thresholds, respectively; all corresponding 95% confidence intervals crossed zero. Post-hoc Riley assessments across plausible model-fit assumptions indicated that the available cohort was below the sample size desirable for model development. The reconstructed cohort sensitivity analysis did not change the overall interpretation.

Discrimination was limited, improvement in probability accuracy was marginal, and incremental discrimination and net benefit were uncertain. The model should be regarded as exploratory rather than clinically implementable; independent validation and improved outcome ascertainment are required.