Welcome to the WSC 2022 Interactive Program

Background and Aims

Methods

Results

Conclusions

Background and Aims

It is known that high-fat diet, induce hypercholesterolemia, deterioration of arterial wall, both morphologically and mechanically. Mechanical changes include thickening of arterial wall, alteration of arterial elasticity, contraction of smooth muscle, increase in sensitivity to pharmacological stimulation and increase in arterial viscoelasticity, i.e., arteriosclerosis. The present study aimed to investigate the effect of shock wave- mediated sonoporation therapy accompanied by high-density lipoprotein (HDL) administration on mechanical parameters of atherosclerotic carotid artery.

Methods

In this study, the New Zealand white rabbits’ common carotid arteries were injured by primary intravascular radiofrequency thermal balloon angioplasty, followed by a 1.5% cholesterol- rich diet for eight weeks. Histology results showed the formation of advanced atherosclerotic plaque with severe stenosis (>70%) and neovascularization in the rabbits’ arteries. Then, the lesioned region treated using electrohydraulic focused shock wave (V= 20 Kv, F= 0.5 Hz, Impulses= 130) accompanied by intravenous HDL (80 mg/kg)- loaded PESDA (Perfluorocarbon- Exposed Sonicated Dextrose Albumin) microbubbles (100ml/kg, 2-5 ×10⁵ bubbles/ml) administration. Arterial biomechanical parameters were evaluated in the groups using B- mode ultrasound images.

Results

Results showed a significant reduction in the mean value for shear elastic modulus, resistive index and a significant increase in the mean value for radial strain, compliance and distensibility in the treatment group compared with the other groups (P<0.05).

Conclusions

Enhanced sonoporation effect of shock wave, induced by collapsed microbubbles, accompanied by Reverse Cholesterol Transport (RCT) effect of HDL and cholesterol efflux effect of shock wave, can cause to regress the advanced atherosclerotic plaque and significantly improve the arterial biomechanical parameters.

Background and Aims

Excessive lipid accumulation by macrophages plays a crucial role in atherosclerosis. Macrophages- derived foam cells are generated by uncontrolled uptake of modified LDL, especially oxidized LDL. We developed an experimental pulsed- low level focused ultrasound (F= 1.1 MHz, I= 3 w/cm², PD= 10 ms) sonotherapy system and investigated its effectiveness on macrophage- derived foam cells density (inflammation) reduction, wherein diagnostic B- mode ultrasound is combined with the therapy system, with a goal of increased safety.

Methods

Briefly, Golden Syrian hamsters underwent primary balloon dilatation at the common carotid artery followed by a 1.5% cholesterol-rich diet injury for three weeks. Histopathology results showed early stage atherosclerosis formation in all of the hamsters' arteries. Then common carotid arteries of the treatment group at the lesioned region, treated using intravenous lipid- based encapsulated methotrexate nanoparticles (10mg/kg) administration accompanied by extracorporeal low level pulsed ultrasonic waves. Foam cells and immune cells density were evaluated in the treatment group compared with the control group using ultrasonography and histopathology.

Results

Results from B-mode ultrasonography and histopathology showed a significant reduction in the mean value for immune cells and foam cells density within the early stage atherosclerotic lesion in the treatment group compared with the control group (p < 0.05).

Conclusions

Enhanced sonoporation effect of ultrasound, induced by inertial cavitation- based collapsed capsules, accompanied by cholesterol efflux and anti- inflammatory effect of ultrasonic therapy (sonotherapy), can cause to enhance cytotoxicity and apoptotic effect of methotrexate and significantly reduce the foam cells and immune cells density and regress the early stage atherosclerosis.

Background and Aims

Intermediate stage atherosclerosis is highlighted by infiltration of oxidized low-density lipoprotein (LDL) and foam cell formation, resulting in the thickening of arterial walls and decreased arterial lumen space. In this study, we aimed to investigate the effect of combined sonoporation and ultrasound therapy on intermediate stage atherosclerosis regression.

Methods

Briefly, Golden Syrian hamsters underwent endothelial denaturation using ballooning at the right common carotid artery, before being fed a 1.5% cholesterol-rich diet. After four weeks, the histopathology results showed foam cells-rich plaque formation, resulting in vessel wall thickening and intermediate stage atherosclerosis formation in all of the hamsters' arteries. Then treatment group underwent pulsed- focused ultrasound (F= 1.1 KHz, P= 15 W, I = 2.5 W/cm², PD= 200 ms) combined sonoporation and ultrasound therapy accompanied by simultaneously intravenous high- dose atorvastatin (5 mg/Kg/day)- loaded PESDA (Perfluorocarbon- Exposed Sonicated Dextrose Albumin) microbubbles (100ml/kg, 2-5 ×10⁵ bubbles/ml) administration.

Results

Results from color Doppler and B-mode ultrasonography and histopathology at the stenotic region showed a significant reduction in the mean value for blood mean velocity, wall mean thickness and the percentage of luminal cross-sectional area of stenosis and a significant increase in the mean value for blood volume flow in the treatment group compared with the other groups (P<0.05).

Conclusions

Enhanced sonoporation effect of focused ultrasound, induced by inertial cavitation effect of collapsed microbubbles, accompanied by lipophilic, pleiotropic and anti- inflammatory effects of atorvastatin and anti- inflammatory and cholesterol efflux effecst of ultrasound therapy, can cause to Intermediate stage atherosclerosis regression and significantly dilate the luminal cross-sectional area of stenosis.

Background and Aims

The prevalence of atherosclerotic carotid artery stenosis (CAS) increases with age, with the global prevalence being approximately 25%. Symptomatic CAS i.e. causing acute ischaemic stroke (AIS) or transient ischaemic attack (TIA) is found in 5-10%; surgical intervention is warranted if >70% to prevent stroke recurrence. However, there is very little evidence of the burden of symptomatic CAS in sub-Saharan Africa (SSA). We set out to ascertain symptomatic CAS in our stroke-accredited centre in Nairobi, Kenya

Methods

As a part of our quality improvement programme, we reviewed our AIS registry from 2016-2021 to elucidate the prevalence of symptomatic CAS as determined by ultrasound. We used the NASCET criteria for categorising CAS severity.

Results

Out of 538 cases, 4.6% (25/538) had multi-territory strokes and 5.0% (27/538) had TIA; none had CAS. Of the remaining patients, 54.2% (292/538) had right and 35.9% left (193/538) MCA territory stroke; 8.8% (43/485) had any degree of CAS with the average symptomatic stenosis being 32% (left) and 41% (right). Only 1.2% (6/485) had >70% CAS that would warrant intervention. Four of these patients underwent carotid endarterectomy and the remainder had best medical therapy.

Conclusions

CAS prevalence was much lower in our stroke cohort, and symptomatic CAS was even rarer when compared to global studies. One other study from Tanzania found symptomatic CAS in 1.8% (1/56) of AIS patients. These consistent findings call for more population-based studies to determine the true burden of CAS in SSA in order to help inform local health policies towards the optimisation of stroke care.

Background and Aims

Vulnerable carotid plaques are related to pathogenesis of ischemic stroke in patients with carotid stenosis. Study aims to compare atherosclerotic plaque characteristics detectable by CT and MRI between vulnerable and stable carotid plaques.

Methods

Patients from the ANTIQUE study with detected carotid artery stenosis and plaque characteristics examined by CT and MRI were included in the analysis. Plaques in vascular territory of TIA or stroke within 90 days were classified as vulnerable. Plaques without clinical or silent infarction in relevant arterial territory were classified as stable. Univariate and multivariate logistic regression analyses were performed to identify risk factors of plaque vulnerability.

Results

Totally 132 patients (91 males; aged 70.0±8.6 years) with 59 vulnerable and 157 stable carotid plaques were included to the analysis. Patients with vulnerable plaque were more likely to consume alcohol (p=0.005), had more severe stenosis detected by CT (median: 80% vs. 72%; p=0.005) and MRI (median: 79% vs. 72%; p=0.005), had more frequently plaque with lipid part (89.8% vs. 76.4%; p=0.035) and lower AHA grade (p=0.028) compared to patients with stable plaques. Multivariate logistic regression analysis identified the alcohol consumption (OR=3.571; 95% CI 1.694–7.527; p=0.001) and stenosis severity (OR=1.037; 95% CI 1.015–1.059; p=0.001) as significant predictors of the recent plaque vulnerability.

Conclusions

Alcohol consumption and degree of carotid stenosis were only predictors of carotid plaque vulnerability.

This work was supported by the Ministry of Health of the Czech Republic grants number NV-19-04-00270, NV-19-08-00362, NU21-09-00357 and NU22-04-00389.

Background and Aims

Prevalence of extracranial carotid stenosis in Sri Lankans and Asians is lower than in white Caucasians. Intracranial arterial stenosis(ICAS) is an important cause of large artery atherosclerotic strokes in Asian countries. However, there is no data on ICAS from Sri Lanka. We aimed to study the prevalence and associations of ICAS in a Sri Lankan stroke.

Methods

We studied all patients with ischaemic stroke admitted to the stroke unit of a tertiary care hospital over a one-year period. Clinical and MRI/MRA data were collected prospectively. Aetiology of strokes was classified according to TOAST criteria.

Results

Of 218 stroke admissions over the study period, 174(79.8%) were ischaemic strokes [116(67.7%) male, mean age 60.4(SD 10.51) years]. MRI +/- MRA was done in 43 ischaemic stroke patients. On TOAST classification, 17(39.9%) were large artery disease (LAD), 9(20.9%) were small vessel disease, 4(9.3%) were cardio-embolic strokes, 2(4.7%) had stroke of other defined aetiology and 11(25.6%) were strokes of undetermined aetiology. Of the LAD patients, 10(66.7%) had intracranial internal carotid artery stenosis, 2(13.3%) had extracranial carotid stenosis, and 3(20.0%) had intracranial posterior circulation stenosis. Of 26 patients who had both MRA and carotid doppler scans, 10(38.5%) had evidence of ICAS on MRA without carotid stenosis on doppler scanning.

Conclusions

These are the first data on ICAS in Sri Lankan stroke patients. Majority of LAD strokes are due to intracranial stenosis. A significant number of ICAS would be missed when only carotid/vertebral imaging studies are done without cerebral angiography.

Background and Aims

The role of surgery for asymptomatic carotid artery stenosis remains unclear due to limited data on prognosis under advanced best medical management. This study aims to investigate the progression of carotid stenosis under current medical management.

Methods

Carotid doppler ultrasound (CDU) performed in 2015 were screened. Cases with ≥60% stenosis were reviewed for follow-up CDUs and progression over 6 years.

Results

Of 2499 CDUs performed in 2015, 256 patients had ≥60% stenosis. After excluding patients with <3 months follow-ups and patients who underwent carotid endarterectomy (CEA), 50 patients were included in final analysis. 18 had complete unilateral carotid occlusion, of which 3 had worsening stenosis of contralateral carotid during 2-5 years follow-up; one of which became symptomatic and had CEA.

Of the remaining 32 patients, 14 had worsening stenosis, with 79% having <70% stenosis on initial CDUs. Seven of them had symptomatic stenosis at initial CDUs; of which 3 required carotid intervention due to recurrent events on medical management. Out of 7 asymptomatic patients, 1 required CEA at year 5.

Eighteen of the 32 patients had no progression in carotid stenosis, with 11% having <70% stenosis on initial CDUs. Four had reduced stenosis at year 4-6 follow-up. Six patients had symptomatic stenosis at initial CDUs with 3 subsequently requiring CEA, of which one had become asymptomatic at 12 months.

Conclusions

Under current advanced medical management, symptomatic stenosis has higher risk of recurrent ischaemic events (38%) than asymptomatic ones (10%) at 3-year follow-up. Patients without progression of stenosis may not preclude recurrent ischemic events.

Background and Aims

We aimed to investigate the efficacy and safety of ticagrelor versus clopidogrel in patients who carry CYP2C19 loss-of-function alleles by presence and clinical presentation of intracranial artery stenosis (ICAS) in CHANCE-2 trial.

Methods

All patients in CHANCE-2 trial were classified into 3 different groups by presence and clinical presentation of ICAS: without ICAS, symptomatic ICAS (sICAS), or asymptomatic ICAS (asICAS). The primary outcome was new stroke, and the safety outcome was severe or moderate bleeding, both within 90 days.

Results

Of all patients in CHANCE-2 trial, 3535 (59.7%) were without ICAS, 1639 (27.7%) with sICAS, and 746 (12.6%) with asICAS. No treatment-by-ICAS group interaction was observed (P=0.14). Among patients without ICAS, new stroke within 90 days occurred in 63 (3.6%) of the 1762 patients in the ticagrelor group and in 112 (6.3%) of the 1773 patients in the clopidogrel group (HR 0.56 [95% CI 0.41–0.77]; P<0.001). Among patients with sICAS, it occurred in 81 (9.6%) of 841 versus 91 (11.4%) of 798 (0.75 [0.55–1.04]; P=0.082), and among those with asICAS, it occurred in 27 (7.4%) of 366 versus 30 (7.9%) of 380 (0.77 [0.43–1.38]; P=0.375). No significant differences of severe or moderate bleeding events in the ticagrelor group compared with the clopidogrel group among patients in different ICAS groups.

Conclusions

The efficacy and safety of ticagrelor versus clopidogrel in preventing new stroke were similar between patients with and those without ICAS, which was consistent with the overall results of the CHANCE-2 trial. The without ICAS group may receive greater benefits.

Background and Aims

Small single subcortical infarction (SSSI) may be classified as parent artery disease-related or only branch involved according to the stenosis of parent artery. The study aimed to evaluate prognoses and the effectiveness of antiplatelet therapy in SSSI.

Methods

We prospectively enrolled 2890 patients with SSSI from the Third China National Stroke Registry database from August 2015 to March 2018. We assessed clinical outcomes and antiplatelet treatment effects in patients with SSSI with and without parent artery stenosis (PAS) identified by magnetic resonance angiography.

Results

Among 2890 patients with SSSI in the perforator territory of MCA and BA, there were 680 (23.53%) patients with PAS and 2210 (76.47%) patients without PAS, respectively. After adjusting for potential confounders, the PAS group had a greater initial stroke severity (OR 1.262, 95% CI 1.058 to 1.505; p=0.0097) and a higher risk of ischaemic stroke recurrence at 3 months (OR 2.266, 95% CI 1.631 to 3.149; p<0.0001) and 1 year (OR 2.054, 95% CI 1.561 to 2.702; p<0.0001), as well as composite vascular events at 3 months (OR 2.306, 95% CI 1.674 to 3.178; p<0.0001) and 1 year (OR 1.983, 95% CI 1.530 to 2.570; p<0.0001), compared with the non-PAS group. In both groups, dual antiplatelet therapy was not superior to single antiplatelet therapy in preventing stroke recurrence, composite vascular events, and disability.

Conclusions

PAS related to significantly higher rates of short-term and long-term stroke recurrence and composite vascular events, suggesting heterogeneous mechanisms in SSSI subgroups. The effectiveness of antiplatelet therapy for SSSI needs further investigation.

Background and Aims

Conventional balloon angioplasty has been challenged for the high incidence of restenosis in patients with intracranial atherosclerotic stenosis (ICAS). To date, drug-coated balloon (DCB) angioplasty has shown a promising efficacy in improving the outcomes in patients with symptomatic ICAS and preventing restenosis. The aim of this study was to compare the safety and efficacy of DCB angioplasty with plain old balloon angioplasty (POBA) for the treatment of symptomatic ICAS.

Methods

A retrospective, non-randomized, single-center case-control study of 100 patients with symptomatic ICAS who were treated with DCB angioplasty or plain old balloon angioplasty was performed at a tertiary stroke center from 2019 to 2021. 1:1 propensity score matching（PSM） was performed to eliminate differences between groups. The periprocedural events and follow-up outcomes were reported.

Results

A total of 49 (49.0%) patients received DCB angioplasty before PSM. After PSM, there were 32 people each in the DCB group and POBA group. No significant difference was found in the baseline characteristics between the two groups. Median follow-up time was 6 months. The rates of stroke and mortality in the perioperative (3.1% [1/32] vs. 6.3% [2/32], P=1) and recurrent ischemic events (6.3% [2/32] vs. 9.4% [3/32], P=1) were not statistically significant between the two groups. The incidence of restenosis (6.3% [2/32] vs. 31.3% [10/32], P=0.010) in the DCB group was significantly lower than that in the POBA group.

Conclusions

The DCB angioplasty appeared efficacious and safe in the treatment of symptomatic ICAS. Compared with plain old balloon angioplasty, DCB angioplasty could effectively reduce the incidence of restenosis.