Role of Hypoperfusion Intensity Ratio in Vessel Occlusions: A Review on Safety and Clinical Outcomes

Efficacy of intravenous thrombolysis in patients with mild acute ischemic stroke and large vessel occlusion with different hypoperfusion volumes

OBJECTIVES

To investigate early treatment strategies for patients with mild acute ischemic stroke and large vessel occlusion, we evaluated the efficacy of intravenous thrombolysis in patients with mild stroke and large vessel occlusion in different hypoperfusion volumes.

METHODS

Cohort data of consecutive patients (October 2021 to June 2024) with anterior circulation large vessel occlusion mild stroke (NIHSS ≤ 5) with onset < 24 h were retrospectively analyzed. We compared the outcomes of patients treated with intravenous thrombolysis (IVT) and dual antiplatelet therapy (DAPT). The outcomes of patients on IVT and DAPT were then compared between the large-volume hypoperfusion group (> 65 ml) and the small-volume hypoperfusion group (≤ 65 ml) based on the hypoperfusion volume of CT perfusion (Tmax > 6s).

RESULTS

A total of 222 patients were enrolled in the study (62 IVT, 160 DAPT). In 111 patients with small-volume hypoperfusion, there was no statistically significant difference in the rate of good prognosis (mRS0-1) at 90 days, the rate of early neurological deterioration and the rate of intracranial hemorrhage between the IVT and DAPT groups (P > 0.05). In another 111 patients with large-volume hypoperfusion, the IVT group had a higher rate of good prognosis (mRS0-1) at 90 days (OR:3.639,95%CI:1.249 ~ 10.601, P:0.018) and a higher rate of intracranial hemorrhage (OR:11.029, 95%CI:1.015 ~ 119.873, P:0.049) compared to the DAPT group.

CONCLUSIONS

In mild acute ischemic stroke patients with large-volume hypoperfusion and large-vessel occlusion, IVT has a higher rate of intracranial hemorrhage but a higher proportion of excellent functional outcomes compared with DAPT. Further randomized controlled trials are needed.

Clinical outcomes of patients with unsuccessful mechanical thrombectomy versus best medical management of medium vessel occlusion stroke in the middle cerebral artery territory

BACKGROUND

Current randomized controlled trials are investigating the efficacy and safety of mechanical thrombectomy (MT) in patients with medium vessel occlusion (MeVO) stroke. Whether best medical management (MM) is more efficient than unsuccessful vessel recanalization during MT remains unknown.

METHODS

This was a retrospective cohort study using data from 37 academic centers across North America, Asia, and Europe between September 2017 and July 2021. Only patients with occlusion of the distal branches (M2 and M3) of the middle cerebral artery territory were included. Unsuccessful MT was defined as a modified Thrombolysis in Cerebral Infarction score of 0-2a. Propensity score matching was used to control for confounders. The primary outcome was functional independence, defined as a modified Rankin Scale (mRS) score of 0-2 at 90 days after treatment. Multivariable regression analysis was used to assess factors associated with the primary outcome.

RESULTS

Of 2903 patients screened for eligibility, 532 patients were analyzed (266 per group) after propensity score matching. The MM group had superior functional outcomes, with 32% achieving mRS 0-1 at 90 days compared with 21% in the MT group (P=0.011). Patients in the MM group also had significantly lower rates of symptomatic intracranial hemorrhage (sICH) (3.4% vs 16%, P<0.001) and any hemorrhage (18% vs 48%, P<0.001). On multivariable regression, unsuccessful MT was associated with reduced odds of functional independence (OR 0.50, 95% CI 0.29 to 0.85, P=0.011) and increased odds of sICH (OR 4.32, 95% CI 1.84 to 10.10, P<0.001). Mortality rates were similar between groups (27% in MM vs 29% in MT, P=0.73).

CONCLUSION

Unsuccessful MT for MeVO was linked to worse outcomes than best MM. These findings highlight the risks of prolonged attempts and emphasize the importance of efficient procedural decision-making to reduce complications and improve patient outcomes.

The relative cerebral blood volume (rCBV) < 42% is independently associated with hemorrhagic transformation in anterior circulation large vessel occlusion

BACKGROUND

Pretreatment CT perfusion (CTP) marker relative cerebral blood volume (rCBV) < 42% lesion volume has recently shown to predict poor collateral status and poor 90-day functional outcome. However, there is a paucity of studies assessing its association with hemorrhagic transformation (HT). Here, we aim to assess the relationship between rCBV < 42% lesion volume with HT.

METHODS

In this retrospective study, we included patients with acute ischemic stroke secondary to large vessel occlusion (AIS-LVO) of anterior circulation who had successful recanalization from two comprehensive stroke centers between 9/1/2017 and 10/01/2023. Successful recanalization was defined as modified treatment in cerebral infarction (mTICI) 2b or greater. Logistic regression analysis and ROC analysis were used to assess the relationship between rCBV <42% and HT.

RESULTS

In total, 150 patients (median age: 69 years, 58.7% female) met our inclusion criteria. On multivariable logistic regression analysis, taking into account age, sex, hypertension, hyperlipidemia, diabetes, prior stroke or transient ischemic attack, admission National Institute of Health stroke scale (NIHSS), Alberta Stroke Program Early CT Score (ASPECTS), and intravenous thrombolysis, rCBV <34% (aOR:1.01, P < .05), rCBV <38% (aOR:1.01, P < .05) and rCBV <42% (aOR:1.01, P < .05) lesion volumes were independently associated with HT. On ROC analysis rCBV < 42% (AUC = 0.61, P < .05) performed slightly better than rCBV < 38% (AUC = 0.59, P < .05) and rCBV < 34% (AUC = 0.59, P < .05) in predicting HT.

CONCLUSION

The rCBV <42% lesion volume is independently associated with HT in AIS-LVO patients who underwent successful recanalization.

Factors Associated With Prolonged Venous Transit in Large Vessel Occlusion Acute Ischemic Strokes

BACKGROUND AND PURPOSE

Prolonged venous transit (PVT), derived from computed tomography perfusion (CTP) time-to-maximum (Tmax) maps, reflects compromised venous outflow (VO) in acute ischemic stroke due to large vessel occlusion (AIS-LVO). Poor VO is associated with worse clinical outcomes, but pre-treatment markers predictive of PVT are not well described.

METHODS

We conducted a retrospective analysis of 189 patients with anterior circulation AIS-LVO who underwent baseline CT evaluation, including non-contrast CT, CT angiography, and CTP. PVT was assessed on Tmax maps; PVT+ was defined as Tmax ≥ 10 s within the posterior superior sagittal sinus or torcula. Baseline clinical data were collected. Multivariable logistic regression identified independent associations between pre-treatment markers and PVT.

RESULTS

PVT+ was identified in 65 patients (34%). In multivariable analysis, higher admission National Institutes of Health Stroke Scale (NIHSS) scores (adjusted odds ratio [aOR], 1.05 per point; 95% confidence interval [CI], 1.01-1.11; P  =  0.028) and male sex (aOR, 1.98; 95% CI, 1.03-3.89; P  =  0.043) were independently associated with PVT+.

CONCLUSIONS

Higher admission NIHSS scores and male sex are independently associated with PVT in anterior circulation AIS-LVO, suggesting that readily available clinical markers may help identify patients with poor VO profiles.