Key result
Faster angiographic MTT during endovascular rescue therapy is linked to ~13-point higher postprocedural autoregulatory time.
Why the study?
Endovascular rescue therapy is used for refractory vasospasm after aneurysmal subarachnoid hemorrhage, but it was unknown whether angiographic perfusion improvement during treatment is associated with increased postprocedural time within the individualized autoregulatory range.
Does angiographic perfusion improvement (reduction in mean transit time) during endovascular rescue therapy increase postprocedural time within the individualized autoregulatory range in patients with aneurysmal subarachnoid hemorrhage and anterior-circulation vasospasm?
Cohort (n=29)
No
Does angiographic perfusion improvement (reduction in mean transit time) during endovascular rescue therapy increase postprocedural time within the individualized autoregulatory range in patients with aneurysmal subarachnoid hemorrhage and anterior-circulation vasospasm?
Intraprocedural reductions in angiographic mean transit time during endovascular rescue therapy for subarachnoid hemorrhage vasospasm are associated with greater postprocedural time spent within the individualized cerebral autoregulatory range, suggesting mean transit time as a candidate physiological biomarker of treatment response.
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MTT reductions during ERT were associated with more postprocedural time in autoregulatory range; leaves open MTT as candidate biomarker pending prospective validation.
BACKGROUND: Endovascular rescue therapy (ERT) is used for refractory vasospasm after aneurysmal subarachnoid hemorrhage, but it is unknown whether angiographic perfusion improvement during ERT is associated with increased time within the individualized autoregulatory range after treatment. We tested whether reductions in angiographic mean transit time (MTT) during ERT were associated with greater postprocedural time within the near-infrared spectroscopy-derived autoregulatory range. METHODS: We performed a retrospective single-center cohort study of patients with aneurysmal subarachnoid hemorrhage who underwent ERT for anterior-circulation vasospasm and had continuous near-infrared spectroscopy monitoring. Cerebral autoregulation was assessed using the cerebral oximetry index to derive optimal mean arterial pressure (MAP Opt ) and the lower and upper limits of autoregulation. Angiographic MTT and time to maximum of the residue function were calculated from digital subtraction angiography. Mixed-effects models tested associations between angiographic perfusion measures, MAP Opt , and change in time within the autoregulatory range after ERT. RESULTS: In 99 observations from 29 patients, the relationship between verapamil dose and ΔMAP Opt depended on pre-ERT MAP Opt (MAP Opt, Before × verapamil interaction: β, −0.0442 [95% CI, −0.0722 to −0.0162]; P =0.0023), meaning the direction of change in MAP Opt differed across baseline autoregulatory states. In 94 baseline angiographic observations, higher pre-ERT MAP Opt was associated with shorter MTT (β, −0.01448 per mm Hg; P =0.011) and shorter time to maximum of the residue function (β, −0.00960 per mm Hg; P =0.0317). In 23 paired observations from 15 patients, each 1-second reduction in MTT during ERT was associated with a 12.9 percentage-point increase in post-ERT time within the autoregulatory range (95% CI, 4.5–21.3; P =0.0085); Δ time to maximum of the residue function was not significantly associated with this outcome. CONCLUSIONS: In this small, single-center cohort, larger intraprocedural reductions in angiographic MTT were associated with increased postprocedural time within the individualized autoregulatory range. These preliminary, hypothesis-generating findings identify angiographic MTT as a candidate physiological biomarker of ERT response that requires prospective validation.
Stoehr et al. (2026) conducted a cohort in Refractory anterior-circulation vasospasm after aneurysmal subarachnoid hemorrhage (n=29). Intraprocedural reduction in angiographic mean transit time (MTT) during endovascular rescue therapy (ERT) was evaluated on Postprocedural change in percentage-point time within the near-infrared spectroscopy-derived autoregulatory range per 1-second reduction in angiographic mean transit time (MTT) (β 12.9 percentage points per 1-s MTT reduction, 95% CI 4.5-21.3, p=0.0085). Each 1-s reduction in angiographic MTT during endovascular rescue therapy increased postprocedural time in the autoregulatory range by 12.9 percentage points (95% CI, 4.5-21.3; P=0.0085).