Neurology: time to stroke, collateral score, and functional outcomes following endovascular treatment for acute ischemic stroke

In ischaemic stroke patients receiving endovascular therapy (EVT), the duration of treatment and collateral status are important predictors of
prognosis.
Recently, experts from the MR CLEAN trial aimed to assess the relationship between the timing of CT angiography (CTA) and a quantitatively determined bypass score, and to assess whether the bypass score changed the relationship between
recanal timing and functional outcomes.
The results were published in the
journal Neurology.

The researchers analyzed data from patients with acute ischemic stroke who had M1 occlusion in the carotid artery or brain and received EVT within 6.
5 hours of symptom onset
, included in the registry of multicenter randomized controlled trials of endovascular treatment of acute ischemic stroke between 2014 and 2017.
Using a validated automated image analysis algorithm, a quantitative score (qCS)
was determined from the baseline CTA.
A visual collateral score (vCS)
of 4 was also determined.
Multivariate regression models were used to assess the relationship between imaging time and qCS, and between re-pass-through time and functional outcomes (90-day mRS score).

A total of 1813 patients
were analyzed.
The median time from symptom onset to CTA was 91 minutes (IQR: 65-150 minutes) and the median qCS was 49% (IQR 25%-78%)
.
The longer time to CTA was not associated with logarithmic converted qCS (adjusted β every 30 min, 0.
002, 95% CI -0.
006 to 0.
011).

Higher qCS (acOR: for each 10% increase: 1.
06, 95% CI 1.
03-1.
09) and shorter re-pass times (acOR per 30 minutes: 1.
17, 95% CI 1.
13 to 1.
22) were independently associated
with the transition to better functional outcomes.
qCS did not change the relationship between re-on-time and functional results (p=0.
28 for interaction).

The results of sensitivity analyses using vCS were similar
.

In summary, in the first 6.
5 hours of ischemic stroke due to carotid artery terminal or M1 occlusion, the collateral state is not affected by the imaging time, and the shorter recanalization time is independent
of the baseline collateral state.

References:

Time Since Stroke Onset, Quantitative Collateral Score, and Functional Outcome After Endovascular Treatment for Acute Ischemic Stroke.
Neurology Oct 2022, 99 (15) e1609-e1618; DOI: 10.
1212/WNL.
0000000000200968