Recanalization, reperfusion, and recirculation in stroke

Impact of cerebral collateral recycle status on clinical outcomes in elderly patients with endovascular stroke treatment

BACKGROUND

Elderly patients are at high risk of acute ischemic stroke caused by large vessel occlusion (AIS-LVO) and usually suffer disability and fatality from stroke even after receiving endovascular treatment (EVT). Previous studies lacked the knowledge of comprehensive cerebral collateral for elderly patients. Hence, we explore the role of cerebral collateral recycle (CCR) status in clinical outcomes in a real-world setting among elderly AIS-LVO patients undergoing EVT.

METHODS

This was a multicenter retrospective cohort study. Computed tomographic angiography (CTA) at admission was applied to evaluate cerebral venous outflow profiles by the Cortical Vein Opacification Score (COVES) and pial arterial collaterals by the Tan scale. According to the status of cerebral collaterals, enrolled patients were divided into the poor, moderate, and favorable CCR groups. The primary outcome was functional independence (90-day modified Rankin Scale score 0-2).

RESULTS

Among 860 AIS-LVO patients receiving EVT, a total of 338 elderly patients were included in the present study after strict screening. Compared with the poor CCR group, the moderate CCR group (31.1 % vs. 10.2 %; adjusted odds ratio[aOR] 3.80; 95 % confidence interval[CI] 1.71-8.44; P = 0.001) and the favorable CCR group (63.3 % vs. 10.2 %; aOR 8.49; 95 % CI 4.02-17.92; P < 0.001) both had a significantly higher rate of functional independence. In subgroup analysis, similar results were found in AIS-LVO patients with older age, large core infarction, or late time window.

CONCLUSION

The cerebral collateral status in elderly patients with AIS-LVO treated by EVT is a strong predictor of functional outcomes and more robust CCR means better outcomes.

The benefit of favorable venous outflow profiles is mediated through the reduced risk of intracranial hemorrhage in acute ischemic stroke patients undergoing endovascular treatment

BACKGROUND

Favorable venous outflow (VO) has been recognized as an independent predictor of excellent clinical outcomes in acute ischemic stroke caused by anterior circulation large vessel occlusion (AIS-LVO) patients who received endovascular treatment (EVT). However, the reasons why VO affects clinical outcomes have not been fully explained. In this study, we aimed to identify the potential mediators of VO affecting prognosis.

METHODS

We conducted a multicenter retrospective cohort study of consecutive patients with AIS-LVO who underwent EVT. Baseline computed tomographic angiography (CTA) was applied to assess VO by the Cortical Vein Opacification Score (COVES). The primary outcome was functional independence at 90 days (modified Rankin Scale (mRS) score of 0-2). Classifying subtypes of intracranial hemorrhage (ICH) to explore the relationship between ICH subtypes and VO. Multivariate logistic regression and causal mediation analyses were used to evaluate the relationship among VO, functional independence, and potential mediators.

RESULTS

Among 860 AIS-LVO patients undergoing EVT, a total of 515 patients were included in the present study after strict screening. In multivariate logistic regression analysis, favorable VO profiles (defined as COVES 3-6) were significantly associated with a lower incidence of ICH (24.2% vs 46.9%, adjusted odds ratio (aOR) 0.48, 95% confidence interval (CI) 0.30 to 0.77, P=0.002) and a higher proportion of functional independence (58.9% vs 15.0%, aOR 4.07, 95% CI 2.41 to 6.88, P<0.001). Mediation analysis showed that favorable VO profiles significantly reduced the incidence of parencuymal hematoma (PH) 2 accounting for 8.0% (95% CI 0.9% to 19.0%) of its beneficial effect on functional independence.

CONCLUSION

This study demonstrated the potential mediating effects of severe ICH for the beneficial effect of favorable VO on clinical prognosis among patients with AIS-LVO who underwent EVT.

Predicting Futile Recanalization by Cerebral Collateral Recycle Status in Patients with Endovascular Stroke Treatment: The CHANOA Score

RATIONALE AND OBJECTIVES

The correlation between collateral circulation and futile recanalization (FR) is still controversial, and few studies have explored the influence of comprehensive cerebral collateral circulation on FR after endovascular stroke treatment. Therefore, based on cerebral collateral recycle (CCR) status, we aimed to establish an effective scoring system to identify the probability of FR.

METHODS

This was a multicenter retrospective cohort study. FR was defined as a 90-day modified Rankin Scale (mRS) score of 3-6, despite having successful recanalization (modified Thrombolysis in Cerebral Infarction score of 2b-3). The discrimination and calibration of this score were assessed using the area under the receiver operator characteristic curve, calibration curve, and decision curve analysis.

RESULTS

Out of 860 patients receiving endovascular stroke treatment, 478 were enrolled in this study after strict screening. In multivariate regression analysis, the CCR status (poor CCR, adjusted OR[aOR] 9.99, 95%CI 5.11 to 17.06, P < 0.001; moderate CCR, aOR 2.94, 95%CI 1.71 -5.06, P < 0.001), age ≥ 80 years (aOR 3.77, P < 0.001), baseline NIHSS ≥ 15 (aOR 1.81, P = 0.018), baseline ASPECTS ≤ 6 (aOR 1.95, P = 0.006), the time from stroke onset to revascularization (OTR) ≥ 600 min (aOR 2.02, P = 0.007) and any intracranial hemorrhage within 48 h (aOR 3.54, P < 0.001) were significantly associated with FR. These factors make up the CCR-hemorrhage-age-NIHSS-OTR-ASPECTS (CHANOA) score. The CHANOA score demonstrated good discrimination and calibration in this cohort, as well as the fivefold cross validation.

CONCLUSION

The CHANOA score reliably predicted FR in patients with endovascular stroke treatment, based on comprehensive cerebral collateral and clinical features.

Neuroprotective effects of all-trans-retinoic acid are mediated via downregulation of TLR4/NF-κB signaling in a rat model of middle cerebral artery occlusion

OBJECTIVES

To determine the effects of all-trans-retinoic acid (ATRA) on the post-stroke inflammatory response and elucidate the underlying molecular mechanisms.

METHODS

This animal experiment was conducted at Central Laboratory, the First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou, China during 2020-2022. Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO) for 1.5 h, and treated with ATRA at 2 and 24 h after reperfusion. Neurological deficit scores on behavioral tests, and cerebral infarct volume, microglial polarization, and the expression levels of inflammatory cytokines and proteins associated with TLR4/NF-κB signaling were assessed.

RESULTS

The ATRA administration reduced cerebral infarct volume and ameliorated neurological deficit scores in MCAO rats. Additionally, ATRA relieved cerebral edema and downregulated the secretion of proinflammatory cytokines after stroke. Finally, ATRA attenuated the polarization of the microglia toward the M1 phenotype and promoted the activation of the beneficial M2 phenotype; the underlying mechanism potentially involved the suppression of the TLR4/NF-κB signaling pathway.

CONCLUSION

The ATRA treatment promoted functional recovery in an experimental model of ischemic stroke by attenuating neural inflammation. ATRA potentially modulated microglia-mediated neuroinflammation via the downregulation of the TLR4/NF-κB signaling pathway, which makes it a candidate treatment for post-stroke neuroinflammation.

Evaluation of extent vs velocity of cortical venous filing in stroke outcome after endovascular thrombectomy

PURPOSE

Abnormal venous drainage may affect the prognosis of patients undergoing endovascular reperfusion therapy (ERT). Herein, time-resolved dynamic computed tomography arteriography (dCTA) was applied to evaluate the relationship between the velocity and extent of cortical venous filling (CVF), collateral status and outcomes.

METHODS

Thirty-five consecutive patients with acute anterior circulation occlusion who underwent ERT within 24 h of onset and successfully recanalized were enrolled. All patients underwent dCTA before ERT. Slow first or end of CVF was considered to occur when the time point of CVF appearance or disappearance on the affected side occurred after than that on the healthy side, whereas an equal CVF, a CVF reduced by ≤ 50%, or by > 50% on the affected side, were considered good, intermediate, and poor CVF extent, respectively.

RESULTS

Slow first CVF (29 patients, 82.8%), slow end of CVF (29, 85.7%), and intermediate extent of CVF (7, 20.0%) were not associated with collateral status or outcomes. Poor extent of CVF (6, 17.1%) was associated with poor collateral status, higher proportion of midline shift, larger final infarct volume, higher modified Rankin Scale (mRS) score at discharge, and higher proportion of in-hospital mortality. All patients with transtentorial herniation had poor extent of CVF, and those with poor CVF extent had an mRS score ≥ 3 at discharge.

CONCLUSION

Poor CVF extent, as assessed by dCTA, is a more accurate and specific marker than slow CVF to identify patients at high risk for poor outcomes after ERT.

Poor Internal Jugular Venous Outflow Is Associated with Poor Cortical Venous Outflow and Outcomes after Successful Endovascular Reperfusion Therapy

Many patients show poor outcomes following endovascular reperfusion therapy (ERT), and poor cortical venous outflow is a risk factor for these poor outcomes. We investigated the association between the outflow of the internal jugular vein (IJV) and baseline cortical venous outflow and the outcomes after ERT. We retrospectively enrolled 78 patients diagnosed with an acute anterior circulation stroke and successful ERT. Poor IJV outflow on the affected side was defined as stenosis ≥50% or occlusion of ipsilateral IJV, and poor outflow of bilateral IJVs was defined as stenosis ≥50% or occlusion of both IJVs. Poor cortical venous outflow was defined as a cortical vein opacification score (COVES) of 0 on admission. Multivariate analysis showed that poor outflow of IJV on the affected side was an independent predictor for hemorrhagic transformation. The poor outflow of bilateral IJVs was an independent risk factor for poor clinical outcomes. These patients also had numerical trends of a higher incidence of symptomatic intracranial hemorrhage, midline shift >10 mm, and in-hospital mortality; however, statistical significance was not observed. Additionally, poor IJV outflow was an independent determinant of poor cortical venous outflow. For acute large vessel occlusion patients, poor IJV outflow is associated with poor baseline cortical venous outflow and outcomes after successful ERT.

Early diagnosis and prediction of intracranial hemorrhage using dual-energy computed tomography after mechanical thrombectomy in patients with acute ischemic stroke

PURPOSE

This study assesses the clinical value of dual-energy computed tomography (DECT) in the early diagnosis of intracranial hemorrhage and evaluates the risk of hemorrhagic transformation in patients with acute ischemic stroke (AIS) after mechanical thrombectomy.

METHODS

Patients with AIS who have undergone thrombectomy with Solitaire stent and DECT within one hour after surgery were prospectively enrolled. Linear mixed energy images, virtual non-contrast (VNC) image, and iodine overlay map (IOM) were obtained. Routine CT scan was performed 24 h postoperatively. The sensitivity, specificity, positive and negative predictive values, and accuracy of DECT in the early diagnosis of intracranial hemorrhage was evaluated. The iodine concentration of intracranial lesions was measured by IOM with the follow-up results taken as reference. Receiver operating characteristic (ROC) analysis was performed to obtain the threshold of hemorrhagic transformation and increased bleeding.

RESULTS

Among the 44 patients enrolled in this study, 25 (56.8 %) were diagnosed with simple extravasation of iodinated contrast agent, and 19 (43.2 %) showed intracranial hemorrhage in DECT. Compared with the follow-up CT 24 h after surgery, early diagnosis of postoperative intracranial hemorrhage using DECT demonstrated a sensitivity of 90.5 %, specificity of 100 %, positive predictive rate of 100 %, negative predictive rate of 92.0 %, and accuracy of 95.5 %. Among the 86 intracranial lesions that underwent iodine concentration measurement, 19 were diagnosed with hemorrhagic transformation or increased bleeding, and 67 were diagnosed without the aforementioned conditions. The sensitivity and specificity for differentiating the two groups were 73.7 % and 92.5 %, respectively, with a cut-off value of 2.7 mg/mL.

CONCLUSION

DECT is clinically valuable in early diagnosis and prediction of intracranial hemorrhage after mechanical thrombectomy in AIS patients.

Management of Elevated Blood Pressure After Stroke Thrombectomy for Anterior Circulation

Thrombectomy is superior to intravenous thrombolysis for patients with large vessel occlusion in acute ischemic stroke, but nearly half of the patients still experience poor functional outcomes. Elevated blood pressure (BP) is widely observed in acute ischemic stroke, and BP may be one of the modifiable parameters that can potentially influence the outcomes; however, only observational studies exist to support current guidelines, and the recommended range for BP after thrombectomy is too wide to meet the clinical requirement. Randomized controlled trials are therefore needed to better understand the relationship between BP and outcomes after thrombectomy. In this review, we introduce the current management of BP after thrombectomy and several aspects of postthrombectomy BP management that should be resolved in future clinical trials.

Argatroban Increased the Basal Vein Drainage and Improved Outcomes in Acute Paraventricular Ischemic Stroke Patients

Background

Since venous drainage in acute arterial ischemic stroke has not been thoroughly researched, we evaluate the effect of argatroban, a selective direct thrombin inhibitor, as a therapy to increase the rate of basal vein Rosenthal (BVR) drainage and improve patients’ post-stroke outcomes.

Material/Methods

In this multicenter clinical trial, 60 eligible patients at 4.5 to 48 hours after the stroke onset were recruited. After being randomly allocated into 2 groups, they were treated with standard therapy either alone or with argatroban.

Results

Compared to the contralateral brain hemisphere, the mean flow velocity (MFV) in BVR drainage was significantly reduced in the stroke-afflicted ipsilateral hemisphere. After treatment with argatroban for 7 days, the MFV from BVR of the ipsilateral hemisphere in the argatroban treated group was significantly increased when compared to the control group. At 90 days after the onset of stroke, the MFV of BVR in the ipsilateral hemisphere was similar in both groups. Compared with controls, the argatroban-treated patients had smaller lesions from baseline to 7 days. Argatroban also improved National Institutes of Health Stroke Scale (NIHSS) scores on day 7 after the onset of stroke. Furthermore, the argatroban group’s neurological functions were superior to those of their untreated counterparts after 90 days. No difference was found in the incidence of adverse reactions between the 2 groups.

Conclusions

These observations indicate that vein drainage change may contribute to the acute phase of brain edema and the outcomes of ischemic stroke patients.

Clinical Trial Registration

URL-http://www.chictr.org

Unique identifier: ChiCTR-IPR-16008663

The efficacy of intravenous thrombolysis in acute ischemic stroke patients with white matter hyperintensity

OBJECTIVES

We aimed to investigate effects of deep white matter hyperintensity (DWMH) and periventricular hyperintensity (PVH) on the efficacy of intravenous thrombolysis (IVT) in patients with acute ischemic stroke (AIS).

METHODS

A total of 113 AIS patients with WMH were categorized into the PVH group and the DWMH group according to the lesion location, with the division of two subgroups based on whether or not they received IVT treatment: the thrombolysis group and the control group. Kaplan-Meier analysis was used for proportional hazards of recurrent stroke. Further, multivariate Cox regression analysis was employed.

RESULTS

Of total patients, there were 62 PVH patients and 51 DWMH patients: 27 of PVH patients and 22 of DWMH patients received IVT, and the remaining patients only received routine treatment. DWMH patients had a higher risk of END (36.4% vs. 11.1%; p = 0.034) and HT (22.7% vs. 3.7%; p = 0.038) than PVH patients in the thrombolysis group. Moreover, DWMH patients undergoing IVT also had a higher risk of END (36.4% vs. 10.3%; x²  = 5.050; p = 0.025) and HT (22.7% vs. 3.4%; x²  = 4.664; p = 0.031) than DWMH patients without IVT. Again, PVH patients had a higher rate of recurrent stroke (20.0% vs. 3.4%; p = 0.034) than DWMH patients in the control group after 90-day follow-up. Kaplan-Meier analysis showed a significant difference in cumulative probability of no major endpoint events (p = 0.039). Further, multivariate Cox regression revealed that PVH is an independent risk factor for stroke recurrence in AIS patients after adjusting confounding factors.

CONCLUSIONS

The location of WMH is closely associated with the efficacy of IVT in AIS patients.

eTICI reperfusion: defining success in endovascular stroke therapy

Background

Revascularization after endovascular therapy for acute ischemic stroke is measured by the Thrombolysis In Cerebral Infarction (TICI) scale, yet variability exists in scale definitions. We examined the degree of reperfusion with the expanded TICI (eTICI) scale and association with outcomes in the HERMES collaboration of recent endovascular trials.

Methods

The HERMES Imaging Core, blind to all other data, evaluated angiography after endovascular therapy in HERMES. A battery of TICI scores (mTICI, TICI, TICI2C) was used to define reperfusion of the initial target occlusion defined by non-invasive imaging and conventional angiography.

Results

Angiography of 801 subjects was available, including 797 defined by non-invasive imaging (154 internal carotid artery (ICA), 583 M1, 60 M2) and 748 by conventional angiography (195 ICA, 459 M1, 94 M2). Among 729 subjects in whom the reperfusion grade could be established, using eTICI (3=100%, 2C=90–99%, 2b67=67–89%, 2b50=50–66%) of the conventional angiography target occlusion, there were 63 eTICI 3 (9%), 166 eTICI 2c (23%), 218 eTICI 2b67 (30%), 103 eTICI 2b50 (14%), 100 eTICI 2a (14%), 19 eTICI 1 (3%), and 60 eTICI 0 (8%). Modified Rankin Scale shift analyses from baseline to 90 days showed that increasing TICI grades were linked with better outcomes, with significant distinctions between TICI 0/1 versus 2a (p=0.028), 2a versus 2b50 (p=0.017), and 2b50 versus 2b67 (p=0.014).

Conclusions

The benefit of endovascular therapy in HERMES was strongly associated with increasing degrees of reperfusion defined by eTICI. The eTICI metric identified meaningful distinctions in clinical outcomes and may be used in future studies and routine practice.

Circular noncoding RNAs as potential therapies and circulating biomarkers for cardiovascular diseases

Recent advancements in genome-wide analyses and RNA-sequencing technologies led to the discovery of small noncoding RNAs, such as microRNAs (miRs), as well as both linear long noncoding RNAs (lncRNAs) and circular long noncoding RNAs (circRNAs). The importance of miRs and lncRNAs in the treatment, prognosis and diagnosis of cardiovascular diseases (CVDs) has been extensively reported. We also previously reviewed their implications in therapies and as biomarkers for CVDs. More recently, circRNAs have also emerged as important regulators in CVDs. CircRNAs are circular genome products that are generated by back splicing of specific regions of pre-messenger RNAs (pre-mRNAs). Growing interest in circRNAs led to the discovery of a wide array of their pathophysiological functions. CircRNAs have been shown to be key regulators of CVDs such as myocardial infarction, atherosclerosis, cardiomyopathy and cardiac fibrosis. Accordingly, circRNAs have been recently proposed as potential therapeutic targets and biomarkers for CVDs. In this review, we summarize the current state of the literature on circRNAs, starting with their biogenesis and global mechanisms of actions. We then provide a synopsis of their involvement in various CVDs. Lastly, we emphasize the great potential of circRNAs as biomarkers for the early detection of CVDs, and discuss several patents and recent papers that highlight the utilization of circRNAs as promising biomarkers.

Collateral pial circulation relates to the degree of brain edema on CT 24 hours after ischemic stroke

Background Cerebral edema is frequent in patients with acute ischemic stroke (AIS) who undergo reperfusion therapy and is associated with high mortality. The impact of collateral pial circulation (CPC) status on the development of edema has not yet been determined. Methods We studied consecutive patients with AIS and documented M1-middle cerebral artery (MCA) and/or distal internal carotid artery (ICA) occlusion who underwent reperfusion treatment. Edema was graded on the 24-hour non-contrast computed tomography (NCCT) scan. CPC was evaluated at the acute phase (≤6 hours) by transcranial color-coded Doppler, angiography and/or CT angiography. We performed an ordinal regression model for the effect of CPC on cerebral edema, adjusting for age, baseline National Institutes of Health Stroke Scale, Alberta Stroke Program Early Computed Tomography Score (ASPECTS) on admission, NCCT, parenchymal hemorrhagic transformation at 24 hours and complete recanalization at six hours. Results Among the 108 patients included, 49.1% were male and mean age was 74.2 ± 11.6 years. Multivariable analysis showed a significant association between cerebral edema and CPC status (OR 0.22, 95% CI 0.08-0.59, p = 0.003), initial ASPECTS (OR 0.72, 95% CI 0.57-0.92, p = 0.007) and parenchymal hemorrhagic transformation (OR 23.67, 95% CI 4.56-122.8, p < 0.001). Conclusions Poor CPC is independently associated with greater cerebral edema 24 hours after AIS in patients who undergo reperfusion treatment.