High relative cerebral blood volume strongly predicts early neurological improvement and good functional outcome in ischemic stroke patients undergoing mechanical thrombectomy
Paweł Wrona1,2, Dominik Wróbel3, Julia Staniszewska4
1Department of Neurology, Jagiellonian University Medical College, Krakow, Poland.
Aim Of The Study:
Despite advancements in mechanical thrombectomy (MT) in the treatment of acute ischemic stroke (AIS) due to large vessel occlusion, nearly half of patients with successful recanalization do not achieve good functional outcome (GFO). We aimed to analyze the association between novel perfusion-based biomarkers and prognosis after AIS.
Clinical Rationale For The Study:
The role of perfusion imaging biomarkers, particularly relative cerebral blood volume (rCBV), as an indicator of tissue-level collateral circulation and a predictor of post-MT clinical trajectory remains insufficiently explored.
Material And Methods:
This single-center retrospective study included patients with anterior circulation AIS who achieved successful recanalization following MT at the Comprehensive Stroke Center, University Hospital, Krakow, between January 2019 and July 2023. We evaluated the predictive value of rCBV for early neurological improvement (ENI) and long-term GFO and compared its prognostic utility with other perfusion-based parameters. Furthermore, we assessed the extent to which the effect of rCBV on GFO was mediated by its influence on ENI. Early neurological improvement was defined as a ≥ 4-point reduction in the National Institutes of Health Stroke Scale score or complete symptom resolution within 24 hours post-admission. GFO was defined as a modified Rankin Scale score of < 3 at 90 days.
Results:
Relative cerebral blood volume was an independent predictor of 90-day GFO after multivariable adjustment (adjusted odds ratio [aOR] = 1.38; 95% confidence interval [CI]: 1.19-1.6; p < 0.001). Additionally, total hypoperfusion volume (T6max) independently contributed to GFO prediction when included alongside rCBV (aOR = 0.96 per 10 mL increase; 95% CI: 0.94-0.99; p = 0.019), enhancing prognostic accuracy. Relative cerebral blood volume was also a strong predictor of ENI (aOR = 1.35; 95% CI: 1.19-1.54; p < 0.001), with 35% (4-67%; p = 0.029) of its effect on GFO mediated through its impact on ENI.
Conclusion And Clinical Implications:
Relative cerebral blood volume is a robust predictor of both early neurological recovery and long-term functional outcome following MT. Moreover, T6max provides independent prognostic value when assessed in conjunction with rCBV, suggesting that these parameters complement each other. Their combined assessment provides a more comprehensive understanding of ischemic tissue fate, aiding clinical decision-making in patients selected for MT.
