External validation of the MR PREDICTS@24H model: predicting functional outcome after endovascular treatment in stroke

Abstract

Background: Chalos et al recently developed the MR PREDICTS@24H model to predict 90 days functional outcomes in ischaemic stroke patients following endovascular treatment (EVT). We aimed to validate this model in the real-world situation of endovascular stroke patients admitted to a tertiary care hospital.

Methods: We conducted a retrospective cohort study including a selection of adult (≥18 years old) ischaemic stroke patients eligible for EVT in a tretiary care center between January 2014 and May 2023. Model performance was assessed using C-statistics for discrimination and calibration plots for goodness of fit.

Results: Among 254 eligible stroke patients, the model demonstrates a strong discriminatory performance for both functional independence (C-statistics 0.92; 95% CI 0.88 to 0.95) and survival (C-statistic 0.83; 95% CI 0.76 to 0.90). Compared with the MR CLEAN Registry, no significant differences were observed in discriminative ability (functional independence: z-score 0.54, p=0.590; survival: z-score -1.66, p=0.0962).

Conclusions: The MR PREDICTS@24H model reliably predicts outcomes in a real-world setting and may help clinicians in the communication with patient relatives.

Keywords: STROKE.

Figure 1. The model input and model performance results for ischaemic stroke patients (n=254). The model input data (A) is provided as median (q1–q3) or frequency (%). (B) The predicted probability of patients with a functional independence (mRS 0–2, n=139; 55%) and (C) the predicted probability of patients who survive (mRS 0–5, n=215; 85%). In addition, the distribution of the probabilities is given. For functional dependence/dead the value 0, and functional independence/alive the value 1. C-statistics, calibration and outcome results are shown in D. Percentages may not sum to 100% due to rounding. CTA, CT angiography; eTICI, Extended Thrombolysis in Cerebral Infarction; ICA, internal carotid artery; ICH, intracerebral haemorrhage; mo, months; mRS, modified Rankin Scale; NIHSS, National Institutes of Health Stroke Scale; No., number.