Between February 2015 and May 2016,
136 patients with an anterior acute ischemic stroke with less than 8 hours from symptoms onset were evaluated. Patients with an occlusion of the intracranial internal carotid artery (TICA) or M1 segment of the middle cerebral artery (MCA) by CTA treated with endovascular reperfusion treatment were evaluated.
After excluding those patients without evaluable mCTA and/or CTP,
90 patients were finally included in the study.
Baseline clinical characteristics of the series are described on Table 1.
Mean age was 72.8±12.4 years and median NIHSS was 18 (IQR 15.5-21).
Sixty-five patients (72.2%) presented with M1-MCA occlusion and 25 (27.8%) with a TICA occlusion.
On mCTA,
70 (77.8%) patients showed good CC (Calgary score 3-5) and 20 (22.2%) poor CC (Calgary score 0-2).
Complete recanalization (TICI 2b-3) was achieved in 74 (82.2%) cases.
At 24 hours,
median NIHSS was 10 (3-18) and mean infarct volume 47.5±8.5 ml.
After 3 months,
48.6% of patients were functionally independents (mRS<3).
Different absolute and relative to contra-lateral hemisphere CTP parameters are described in the Table 2.
Univariate analysis showed that almost all absolute and relative CTP parameters were associated with CC by mCTA on the cROI,
but not the sROI.
The CTP values with stronger association with mCTA CC classification were selected for secondary analysis (absolute (cROI-CBV) and relative to contralateral cortical ROI-CBV (REL-cROI-CBV)).
We designed a Receiver Operating Characteristic (ROC) curve to identify the cut-off points with higher sensitivity and specificity to predict good CC on mCTA (Figure 1).
An absolute value of the cROI-CBV >2.83 ml/100mg predicted good CC with an 80% of sensitivity and 70% of specificity (AUC 0.79,
p<0.001).
A REL-cROI-CBV value >0.93 predicted good CC with an 83% of sensitivity and 80% of specificity (AUC 0.80,
p<0.001).
A logistic regression model with cROI CTP parameters adjusted by age,
baseline NIHSS and complete recanalization was performed to identify independent predictors of 24h low infarct volume on control CT (vol <50cc). cROI-CBV>2.83 emerged as independent predictor of lower 24 hours infarct volume (OR 6.9,
CI 95% 2.3-21.2; p<0.001),
together with complete recanalization (OR 9.2,
CI 95% 2.5-33.9; p<0.001).
Both cROI-CBV and REL-cROI-CBV were associated with higher NIHSS decrease at 24 hours (p=0.007 and p<0.001).
However,
logistic regression analysis adjusted by age,
baseline NIHSS,
complete recanalization and both cROI-CBV and REL-cROI-CBV showed that only complete recanalization emerged as an independent predictor of early clinical improvement (OR 5.1,
CI 1.5-16.6,
p=0.007).