New SASt Score Predicts Stroke Outcomes Using Arterial Stiffness Measures
Combining stroke severity with vascular aging metrics, the SASt score achieves 87% accuracy predicting poor 3-month recovery in stroke patients.
Summary
Researchers developed a new clinical scoring tool called the SASt score by combining the NIH Stroke Scale (NIHSS) with estimated pulse wave velocity (ePWV), a marker of arterial stiffness and vascular aging. Studying 2,730 acute ischemic stroke patients who underwent 24-hour blood pressure monitoring, they found ePWV alone predicted poor functional outcomes at 3 months with an AUC of 0.77. The combined SASt score achieved an impressive AUC of 0.87, outperforming existing vascular aging measures like the early vascular aging ambulatory score and 24-hour pulse pressure. These findings suggest that incorporating arterial stiffness into stroke prognosis could meaningfully improve how clinicians identify high-risk patients after stroke.
Detailed Summary
Stroke recovery is notoriously difficult to predict, and current tools often overlook the contribution of vascular aging to long-term outcomes. Arterial stiffness — a hallmark of accelerated vascular aging — is known to worsen cardiovascular risk, but its specific role in stroke prognosis has been underexplored. This study aimed to fill that gap by evaluating three non-invasive vascular aging markers and combining the strongest with a standard clinical measure into a new prognostic score.
The study enrolled 2,730 acute ischemic stroke patients with a mean age of 72 years across multiple international centers. All patients underwent 24-hour ambulatory blood pressure monitoring shortly after stroke. Three vascular aging indices were derived: estimated pulse wave velocity (ePWV), the early vascular aging ambulatory score (EVAAs), and 24-hour pulse pressure (24h-PP). The primary outcome was poor functional recovery, defined as a modified Rankin Scale score greater than 2 at three months post-stroke.
Among the three measures, ePWV demonstrated the strongest predictive power, with an AUC of 0.77 and an optimal cutoff of 12.2 m/s. EVAAs and 24h-PP showed weaker discrimination. The newly formulated SASt score — calculated as NIHSS plus twice the ePWV value — achieved an AUC of 0.87, representing an excellent improvement over stroke severity assessment alone.
These results suggest that arterial stiffness, readily estimated from standard blood pressure monitoring, adds meaningful prognostic information beyond neurological deficit scoring. The SASt score could help clinicians stratify high-risk patients earlier, enabling more intensive rehabilitation or monitoring.
However, the study is retrospective in design, and the SASt score requires prospective validation across diverse stroke populations before it can be recommended for routine clinical use.
Key Findings
- ePWV predicted poor 3-month stroke outcomes with AUC of 0.77 and optimal cutoff of 12.2 m/s.
- The novel SASt score (NIHSS + 2×ePWV) achieved AUC of 0.87 for predicting poor functional recovery.
- SASt score outperformed EVAAs and 24-hour pulse pressure as prognostic tools post-stroke.
- Study included 2,730 patients across multiple international centers, strengthening generalizability.
- Vascular aging measured non-invasively via 24-hour blood pressure monitoring adds prognostic value.
Methodology
This was a multicenter observational study of 2,730 acute ischemic stroke patients who underwent 24-hour ambulatory blood pressure monitoring. Three vascular aging indices were derived and evaluated against functional outcomes at 3 months using receiver operating characteristic analysis. The SASt score was developed by combining NIHSS with ePWV using logistic regression-informed weighting.
Study Limitations
The retrospective design limits causal inference and may introduce selection bias. The SASt score has not yet been validated in prospective or independent cohorts, limiting immediate clinical applicability. Generalizability may be constrained by the relatively older mean patient age and multicenter heterogeneity in monitoring protocols.
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