Alperen Elek, Ferhat Kıran, Parya Valizadeh, Adil Ahmed, Mehmet Can Pence, Ram Kadirvel, Waleed Brinjikji, Girish Bathla, David F Kallmes, Cem Bilgin
Baseline pc-ASPECTS is a clinically useful, imaging-modality-independent marker of 90-day functional outcome after EVT for posterior circulation stroke. Prognostic performance did not differ significantly across modalities; however, the absence of a statistically significant difference should not be interpreted as formal equivalence, and pc-ASPECTS is best applied as one component of multimodal risk stratification rather than as a stand-alone threshold for treatment selection.
BACKGROUND: The posterior circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS; range 0-10) is a region-based scoring system designed to quantify early ischemic change in the vertebrobasilar territory and is increasingly used to inform patient selection for endovascular therapy. However, whether its prognostic performance depends on the imaging modality used to derive the score remains incompletely characterized.
METHODS: PubMed, Scopus, and Web of Science were searched for studies reporting pc-ASPECTS prior to endovascular therapy (EVT) ± IVT and 90-day modified Rankin Scale (mRS) outcomes across diffusion-weighted imaging (DWI), CT angiography source imaging (CTA-SI), and non-contrast computed tomography (NCCT). When studies reported both perfusion-derived parameters and pc-ASPECTS, only pc-ASPECTS-derived data were extracted. Between-group differences in pc-ASPECTS and other clinical metrics were quantified as Standardized Mean Differences (SMDs) using either a Bayesian framework or restricted maximum likelihood (REML) estimation.
RESULTS: Forty-eight studies (4,853 patients) were included; five cohorts contributed two modality-specific datasets each, yielding 51 imaging datasets that were used only in the modality-stratified analyses. Across all imaging modalities, patients with favorable outcomes had significantly higher pc-ASPECTS values (Bayesian pooled SMD 0.78, 95% credible interval [CrI] 0.61-0.95). Modality-specific analyses showed consistent effects for DWI (SMD 1.01, 95% CrI 0.74-1.29), NCCT (SMD 0.76, 95% CrI 0.29-1.24), and CTA-SI (SMD 0.59, 95% CrI 0.26-0.92) with no statistically significant between-modality difference detected (p = 0.26). In per-point analyses, each 1-point decrease in pc-ASPECTS was associated with a 1.48-fold increase in the odds of unfavorable outcome (OR 1.48, 95% CI 1.33-1.54; I2 = 31.8% p <0.01). Sensitivity analyses confirmed the robustness of the primary findings.
CONCLUSIONS: Baseline pc-ASPECTS is a clinically useful, imaging-modality-independent marker of 90-day functional outcome after EVT for posterior circulation stroke. Prognostic performance did not differ significantly across modalities; however, the absence of a statistically significant difference should not be interpreted as formal equivalence, and pc-ASPECTS is best applied as one component of multimodal risk stratification rather than as a stand-alone threshold for treatment selection.