The Role of Antiplatelet Therapy in Carotid Stenting for Ischemic Stroke Prevention

A case of de novo extra-stent ulceration induced by persistent plaque protrusion after carotid artery stenting with a CASPER stent for a large-volume unstable plaque

Plaque protrusion (PP) has been identified as a perioperative complication of carotid artery stenosis treated with carotid artery stenting (CAS). The CASPER stent (CS), a dual-layer micromesh stent, may be able to prevent PP. Despite using CS, de novo extra-stent ulceration induced by persistent PP is rare. A 75-year-old male patient, whose superficial temporal artery-middle cerebral artery bypass tended to occlude, underwent CAS using a CS for symptomatic pseudo-occlusive internal carotid artery with a large-volume unstable plaque. This led to de novo extra-stent ulceration induced by persistent PP, resulting in ischemic stroke that necessitated the application of the stent-in-stent technique. There was no recurrence of cerebral infarction postoperatively at 12 months. Here, we present, to the best of our knowledge, the first case of a patient with de novo extra-stent ulceration induced by persistent PP after CAS that led to de novo extra-stent ulceration. The inhibition of intimal formation on the stent surface caused by persistent PP was considered to be the underlying mechanism. The stent-in-stent technique is beneficial even in cases of PP accompanied by de novo extra-stent ulceration.

Predictors of symptomatic intracerebral hemorrhage after endovascular treatment for acute ischemic stroke due to tandem lesion in anterior circulation

BACKGROUND

Endovascular treatment (EVT) of tandem lesion (TL) in the anterior circulation acute ischemic stroke (IS) usually requires periprocedural antithrombotic treatment and early initiation of dual antiplatelet therapy (DAPT) after carotid stenting. However, it may contribute to an occurrence of symptomatic intracerebral hemorrhage (SICH) in some cases. We investigated factors influencing the SICH occurrence and assessed the possible predictors of SICH after EVT.

METHODS

IS patients with TL in the anterior circulation treated with EVT were enrolled in the multicenter retrospective ASCENT study. A good three-month clinical outcome was scored as 0-2 points in modified Rankin Scale (mRS) and recanalization using the TICI scale. SICH was assessed using the SITS-MOST criteria. Logistic regression analysis was used for the assessment of possible predictors of SICH with adjustment for potential confounders.

RESULTS

In total, 300 (68.7 % males, mean age 67.3 ± 10.2 years) patients with median of admission NIHSS 17 were analyzed. Recanalization (TICI 2b-3) was achieved in 290 (96.7 %) patients and 176 (58.7 %) had mRS 0-2. SICH occurred in 25 (8.3 %) patients. Patients with SICH did not differ from those without SICH in the rate of periprocedural antithrombotic treatment (64 vs. 57.5 %, p = 0.526) and in the rate of DAPT started within the first 12 h after EVT (20 vs. 42.2 %, p = 0.087). After adjustment, admission NIHSS and admission glycemia were found as the only predictors of SICH after EVT.

CONCLUSION

Admission NIHSS and glycemia were found as the only predictors of SICH after EVT for TL. No associations between periprocedural antithrombotic treatment, early start of DAPT after EVT and SICH occurrence were found.

Intravenous thrombolysis plus mechanical thrombectomy versus mechanical thrombectomy alone for acute ischemic stroke: A systematic review and updated meta-analysis of clinical trials

BACKGROUND

Mechanical thrombectomy (MT) is the gold standard treatment for large vessel occlusion (LVO). A vital factor that might influence MT outcomes is the use of intravenous thrombolysis (IVT). A few clinical trials in this domain thus far have not yielded consistent outcomes. We conducted this meta-analysis to synthesize collective evidence in this regard.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement guidelines were followed, and we performed a comprehensive literature search of four databases (PubMed, Scopus, Web of Science, Cochrane CENTRAL). For outcomes constituting continuous data, the mean difference (MD) and its standard deviation (SD) were pooled. For outcomes constituting dichotomous data, the frequency of events and the total number of patients were pooled as the risk ratio (RR).

RESULTS

Seven clinical trials with a total of 2317 patients are included in this meta-analysis. Six trials are randomized, and one trial was nonrandomized. No significant differences were found between MT plus IVT and MT alone in successful recanalization (RR 1.04, 95% Confidence Interval (CI) [0.92 to 1.17], P = 0.53), 90-day functional independence (RR 1.03, 95% CI [0.90 to 1.19], P = 0.65), symptomatic intracranial hemorrhage (sICH) (RR 1.22, 95% CI [0.84 to 1.75], P = 0.30), or mortality (RR 0.94, 95% CI [0.76 to 1.18], P = 0.61).

CONCLUSION

The current evidence does not favor either MT plus IVT or MT alone for LVO except for the procedural time. More trials are needed in this regard, and certain factors should be considered when comparing the two approaches.

Safety of Tailored Transfemoral Carotid Artery Stenting for Symptomatic Elderly Patients: A Single Center Observational Study

OBJECTIVE

Transfemoral carotid artery stenting (TFCAS) in symptomatic elderly patients (≥70 years old) may have a high periprocedural stroke rate. This study was performed to examine whether tailored TFCAS for symptomatic elderly patients is as safe as that for symptomatic nonelderly patients.

METHODS

The subjects were 185 patients with symptomatic internal carotid artery stenosis. Tailored TFCAS including postoperative management was performed based on preoperative examinations of vascular anatomy, plaque imaging, platelet aggregation activity, and cerebral hemodynamic impairment. The major 30-day perioperative stroke rates were examined.

RESULTS

The patients included 51 (27.6%) <70 (group Y) and 134 (72.4%) ≥70 (group E) years old. Group E included significantly more cases with an elongated aortic arch, tortuous target lesion, and longer plaques (all P < 0.05). Among all cases, 181 (97.8%) procedures were performed as per preoperative planning. Group E had more frequent use of a proximal embolic protection device and a closed-cell or dual-layer micromesh stent (all P < 0.05). Seven patients (3.8%) had major stroke. Rates of major ischemic stroke (2.0% vs. 3.0%, P = 1.00) and intracranial hemorrhage (2.0% vs. 0.8%, P = 0.48) were low and did not differ significantly between groups Y and E.

CONCLUSIONS

Symptomatic elderly patients have several unfavorable factors. However, tailored TFCAS for each patient based on preoperative examinations in symptomatic elderly patients may be as safe as that in symptomatic nonelderly patients.

Safety Outcomes of Antiplatelet Therapy During Endovascular Treatment of Tandem Lesions in Acute Ischemic Stroke Patients

Risk of hemorrhage remains with antiplatelet medications required with carotid stenting during endovascular therapy (EVT) for tandem lesion (TLs). We evaluated the safety of antiplatelet regimens in EVT of TLs. This multicenter study included anterior circulation TL patients from 2015 to 2020, stratified by periprocedural EVT antiplatelet strategy: (1) no antiplatelets, (2) single oral, (3) dual oral, and (4) intravenous IV (in combination with single or dual oral). Primary outcome was symptomatic intracranial hemorrhage (sICH). Secondary outcomes were any hemorrhage, favorable functional status (mRS 0-2) at 90 days, successful reperfusion (mTICI score ≥ 2b), in-stent thrombosis, and mortality at 90 days. Of the total 691 patients, 595 were included in the final analysis. One hundred and nineteen (20%) received no antiplatelets, 134 (22.5%) received single oral, 152 (25.5%) dual oral, and 196 (31.9%) IV combination. No significant association was found for sICH (ref: no antiplatelet: 5.7%; single:4.2%; aOR 0.64, CI 0.20-2.06, p = 0.45, dual:1.9%; aOR 0.35, CI 0.09-1.43, p = 0.15, IV combination: 6.1%; aOR 1.05, CI 0.39-2.85, p = 0.92). No association was found for parenchymal or petechial hemorrhage. Odds of successful reperfusion were significantly higher with dual oral (aOR 5.85, CI 2.12-16.14, p = 0.001) and IV combination (aOR 2.35, CI 1.07-5.18, p = 0.035) compared with no antiplatelets. Odds of excellent reperfusion (mTICI 2c/3) were significantly higher for cangrelor (aOR 4.41; CI 1.2-16.28; p = 0.026). No differences were noted for mRS 0-2 at 90 days, in-stent thrombosis, and mortality rates. Administration of dual oral and IV (in combination with single or dual oral) antiplatelets during EVT was associated with significantly increased odds of successful reperfusion without an increased rate of symptomatic hemorrhage or mortality in patients with anterior circulation TLs.

Tectorigenin: A Review of Its Sources, Pharmacology, Toxicity, and Pharmacokinetics

Tectorigenin is a well-known natural flavonoid aglycone and an active component that exists in numerous plants. Growing evidence suggests that tectorigenin has multiple pharmacological effects, such as anticancer, antidiabetic, hepatoprotective, anti-inflammatory, antioxidative, antimicrobial, cardioprotective, and neuroprotective. These pharmacological properties provide the basis for the treatment of many kinds of illnesses, including several types of cancer, diabetes, hepatic fibrosis, osteoarthritis, Alzheimer's disease, etc. The purpose of this paper is to provide a comprehensive summary and review of the sources, extraction and synthesis, pharmacological effects, toxicity, pharmacokinetics, and delivery strategy aspects of tectorigenin. Tectorigenin may exert certain cytotoxicity, which is related to the administration time and concentration. Pharmacokinetic studies have demonstrated that the main metabolic pathways in rats for tectorigenin are glucuronidation, sulfation, demethylation and methoxylation, but that it exhibits poor bioavailability. From our perspective, further research on tectorigenin should cover: exploring the pharmacological targets and mechanisms of action; finding an appropriate concentration to balance pharmacological effects and toxicity; attempting diversified delivery strategies to improve the bioavailability; and structural modification to obtain tectorigenin derivatives with higher pharmacological activity.

Quantification of new intracerebral lesions on diffusion-weighted magnetic resonance imaging after transcarotid artery revascularization for treatment of carotid artery stenosis

Objective

Transcarotid artery revascularization (TCAR) has been used with increasing prevalence for treatment of carotid artery stenosis. TCAR holds potential benefits over traditional carotid endarterectomy (CEA) or transfemoral carotid artery stenting by its nature of being less invasive than CEA but more neuroprotective than transfemoral carotid artery stenting. The purpose of this pilot study is to evaluate the effectiveness of the neuroprotection system of TCAR with flow reversal by quantifying the incidence and degree of new intracerebral lesions using diffusion-weighted magnetic resonance imaging (DW-MRI). This study is the first to evaluate these findings in a real-world, high-risk cohort, who would have been excluded from the ROADSTER and ENROUTE transcarotid neuroprotection system DW-MRI studies.

Methods

Patients undergoing unilateral TCAR for symptomatic or asymptomatic severe internal carotid artery disease were eligible and prospectively enrolled in the study. All patients had high risk features, including comorbidities or medications, which excluded them from industry-sponsored DW-MRI trials. Patients underwent a preoperative DW-MRI to obtain a baseline intracerebral evaluation within 1 week of the scheduled surgery. The follow-up DW-MRI occurred within 48 hours postoperatively. The primary outcome was new, acute postoperative lesion(s) identified on DW-MRI. Secondary outcomes include any major stroke, myocardial infarction, or death during hospitalization.

Results

Five consecutive patients underwent TCAR with preoperative and postoperative imaging. All five patients were on dual antiplatelet therapy before their procedure and verified to be therapeutic on these agents. All patients underwent a right-sided TCAR and three were symptomatic as the indication for their procedure. All five patients demonstrated chronic lesions on the preoperative DW-MRI. Technical success was achieved in all five patients, with one operative complication involving a dissection of the common carotid at the access site, which was stented using the TCAR system. Postoperative DW-MRI did not identify any new intracerebral lesions in any patient following the procedure. No patient had a stroke, myocardial infarction, or death during hospitalization.

Conclusions

In this real-world, high-risk cohort, TCAR was completed with no evidence of new, postoperative DW-MRI lesions. These data further demonstrate that TCAR with flow reversal is an effective neuroprotective strategy for carotid revascularization. Further study is warranted to evaluate DW-MRI differences between TCAR and CEA.

Carotid Restenosis Rate After Stenting for Primary Lesions Versus Restenosis After Endarterectomy With Creation of Risk Index

PURPOSE

Carotid artery stenting (CAS) is an option for carotid restenosis (CR) treatment with favorable outcomes. However, CAS has also emerged as an alternative to carotid endarterectomy (CEA) for the management of patients with primary carotid stenosis. This study aimed to report CR rates after CAS was performed in patients with primary lesions versus restenosis after CEA, to identify predictors of CR, and to report both neurological and overall outcomes.

MATERIALS AND METHODS

From January 2000 to September 2018, a total of 782 patients were divided into 2 groups: The CAS (prim) group consisted of 440 patients in whom CAS was performed for primary lesions, and the CAS (res) group consisted of 342 patients with CAS due to restenosis after CEA. Indications for CAS were symptomatic stenosis/restenosis >70% and asymptomatic stenosis/restenosis >85%. A color duplex scan (CDS) of carotid arteries was performed 6 months after CAS, after 1 year, and annually afterward. Follow-up ranged from 12 to 88 months, with a mean follow-up of 34.6±18.0 months.

RESULTS

There were no differences in terms of CR rate between the patients in the CAS (prim) and CAS (res) groups (8.7% vs 7.2%, χ²=0.691, p=0.406). The overall CR rate was 7.9%, whereas significant CR (>70%) rate needing re-intervention was 5.6%, but there was no difference between patients in the CAS (prim) and CAS (res) groups (6.4% vs 4.7%, p=0.351). Six independent predictors for CR were smoking, associated previous myocardial infarction and angina pectoris, plaque morphology, spasm after CAS, the use of FilterWire or Spider Fx cerebral protection devices, and time after stenting. A carotid restenosis risk index (CRRI) was created based on these predictors and ranged from -7 (minimal risk) to +10 (maximum risk); patients with a score >-4 were at increased risk for CR. There were no differences in terms of neurological and overall morbidity and mortality between the 2 groups.

CONCLUSIONS

There was no difference in CR rate after CAS between the patients with primary stenosis and restenosis after CEA. A CRRI score >-4 is a criterion for identifying high-risk patients for post-CAS CR that should be tested in future randomized trials.

Acute ischemic stroke with cervical internal carotid artery steno-occlusive lesion: multicenter analysis of endovascular approaches

BACKGROUND

Occlusion of the internal carotid artery (ICA), whether isolated or in the setting of a tandem lesion (TL) have a poor response to treatment with intravenous thrombolysis. Previous studies ​​have demonstrated the superiority of mechanical thrombectomy in the treatment of acute ischemic stroke (AIS) following large vessel occlusion, compared to standard intravenous fibrinolysis. The aim of our study was to describe endovascular treatment (EVT) in AIS due to isolated ICA occlusion or TL.

METHODS

We assessed the association between 90-day outcome and clinical, demographic, imaging, and procedure data in 51 consecutive patients with acute isolated ICA occlusion or TL who underwent EVT. We evaluated baseline NIHSS and mRS, ASPECTS, type of occlusion, stent placement, use of stent retrievers and/or thromboaspiration, duration of the procedure, mTICI, postprocedural therapy and complications.

RESULTS

A favorable 90-day outcome (mRS 0-2) was achieved in 34 patients (67 %) and was significantly associated with the use of dual antiplatelet therapy after the procedure (p = 0.008), shorter procedure duration (p = 0.031), TICI 2b-3 (p < 0.001) and lack of post-procedural hemorrhagic transformation (p = 0.001). Four patients did not survive, resulting in a mortality rate of 8 %.

CONCLUSIONS

Our study has shown that EVT in the treatment of AIS due to ICA occlusion is safe, and effective in determining a good functional outcome. ICA stenting led to good angiographic results and therapy with a glycoprotein IIb / IIIa inhibitor immediately after stent release did not result in a greater risk of hemorrhage. The use of post-procedural dual antiplatelet therapy was associated with favorable outcome, without a significant increase in hemorrhagic transformation.

Periprocedural Variability of Platelet Functions in Carotid Artery Stenting: An Analysis Using VerifyNow

Objective

The assessment of platelet functions is necessary to prevent both thromboembolic and hemorrhagic complications under dual antiplatelet therapy (DAPT). Using the VerifyNow (Accumetrics, Inc., San Diego, CA, USA) assay, this study aimed to reveal time-dependent changes in platelet functions after carotid artery stenting (CAS).

Methods

We enrolled retrospectively 43 patients who underwent CAS under DAPT. Aspirin reaction unit (ARU) and P2Y12 reaction unit (PRU) values were determined on the day before and on days 1, 3, and 7 after the procedure. Multiple comparison tests (MCTs) were performed among ARU and PRU measurement points, and the proportions of hypo- and hyper-responses were compared.

Results

The median ARU values were 408 (interquartile range: 392-497) before CAS and 418 (405-470) on day 1, 405 (393.0-460.5) on day 3, and 402 (388.5-477.5) on day 7 (not significant in MCTs). The percentages of hypo-responses were 16.3%, 7.0%, 2.3%, and 7.0%, respectively (p = 0.11). The significantly different median PRU values were 173 (116.5-209.5), 233 (166.5-273.5), 139 (70.5-205.5), and 51 (9.0-79.5), respectively. The median PRU was before the procedure within the therapeutic range but exceeded the upper cutoff on day 1 and was below the lower cutoff on day 7. The percentages of hypo-responses were 14.0%, 51.2%, 18.6%, and 11.6%, respectively (p <0.001) and the percentages of hyper-responses were 9.3%, 2.3%, 23.3%, and 62.8%, respectively (p <0.001).

Conclusion

In the periprocedural CAS period, ARU values were stable, but PRU values showed time-dependent changes. PRU values were above the therapeutic range the day after CAS but decreased below this range on day 7.

Impact of Antiplatelet Therapy During Endovascular Therapy for Tandem Occlusions

Background and Purpose—

Antiplatelet agents could be used in the setting of endovascular therapy for tandem occlusions to reduce the risk of de novo intracranial embolic migration, reocclusion of the extracranial internal carotid artery lesion, or in-stent thrombosis in case of carotid stent placement but have to be balanced with the intracerebral hemorrhagic transformation risk. In this study, we aim to investigate the impact of acute antiplatelet therapy administration on outcomes during endovascular therapy for anterior circulation tandem occlusions.

Methods—

This is a retrospective analysis of a collaborative pooled analysis of 11 prospective databases from the multicenter observational TITAN registry (Thrombectomy in Tandem Lesions). Patients were divided into groups based on the number of antiplatelet administered during endovascular therapy. The primary outcome was favorable outcome, defined as a modified Rankin Scale score of 0 to 2 at 90 days.

Results—

This study included a total of 369 patients; 145 (39.3%) did not receive any antiplatelet agent and 224 (60.7%) received at least 1 antiplatelet agent during the procedure. Rate of favorable outcome was nonsignificantly higher in patients treated with antiplatelet therapy (58.3%) compared with those treated without antiplatelet (46.0%; adjusted odds ratio, 1.38 [95% CI, 0.78–2.43]; P =0.26). Rate of 90-day mortality was significantly lower in patients treated with antiplatelet therapy (11.2% versus 18.7%; adjusted odds ratio, 0.47 [95% CI, 0.22–0.98]; P =0.042), without increasing the risk of any intracerebral hemorrhage. Successful reperfusion (modified Thrombolysis in Cerebral Ischemia score 2b-3) rate was significantly better in the antiplatelet therapy group (83.9% versus 71.0%; adjusted odds ratio, 1.89 [95% CI, 1.01–3.64]; P =0.045).

Conclusions—

Administration of antiplatelet therapy during endovascular therapy for anterior circulation tandem occlusions was safe and was associated with a lower 90-day mortality. Optimal antiplatelet therapy remains to be assessed, especially when emergent carotid artery stenting is performed. Further randomized controlled trials are needed.

Antiplatelet therapy within 24 hours of tPA: lessons learned from patients requiring combined thrombectomy and stenting for acute ischemic stroke

Objective

Although stroke guidelines recommend antiplatelets be started 24 hours after tissue plasminogen activator (tPA), select mechanical thrombectomy (MT) patients with luminal irregularities or underlying intracranial atherosclerotic disease may benefit from earlier antiplatelet administration.

Methods

We explore the safety of early (<24 hours) post-tPA antiplatelet use by retrospectively reviewing patients who underwent MT and stent placement for acute ischemic stroke from June 2015 to April 2018 at our institution.

Results

Six patients met inclusion criteria. Median presenting and pre-operative National Institutes of Health Stroke Scale scores were 14 (Interquartile Range [IQR] 5.5–17.3) and 16 (IQR 13.7–18.7), respectively. Five patients received standard intravenous (IV) tPA and one patient received intra-arterial tPA. Median time from symptom onset to IV tPA was 120 min (IQR 78–204 min). Median time between tPA and antiplatelet administration was 4.9 hours (IQR 3.0–6.7 hours). Clots were successfully removed from the internal carotid artery (ICA) or middle cerebral artery (MCA) in 5 patients, the anterior cerebral artery (ACA) in one patient, and the vertebrobasilar junction in one patient. All patients underwent MT before stenting and achieved thrombolysis in cerebral infarction 2B recanalization. Stents were placed in the ICA (n=4), common carotid artery (n=1), and basilar artery (n=1). The median time from stroke onset to endovascular access was 185 min (IQR 136–417 min). No patients experienced symptomatic post-procedure intracranial hemorrhage (ICH). Median modified Rankin Scale score on discharge was 3.5.

Conclusions

Antiplatelets within 24 hours of tPA did not result in symptomatic ICH in this series. The safety and efficacy of early antiplatelet administration after tPA in select patients following mechanical thrombectomy warrants further study.

Lipoprotein-Associated Phospholipase A2 is Linked with Poor Cardio-Metabolic Profile in Patients with Ischemic Stroke: A Study of Effects of Statins

Objectives

The objective of the study is to investigate the effects of statins on the lipoprotein-associated phospholipase A2 (Lp-PLA2) mass in patients with ischemic stroke.

Materials and Methods

A total number of 59 patient ages 43-69 years with cerebral stroke compared to 39 healthy controls that matching the age and body weight. The patients were divided into 32 patients on statins therapy assigned as statins users and 27 patients, not on statins therapy assigned as nonstatins users. Anthropometric and biochemical measurements were done including lipid profile and inflammatory biomarkers.

Results

Stroke patients on statins therapy showed a comparable low of Lp-PLA (29.82 ± 3.19 IU/mL) to nonstatins user stroke patients (15.58 ± 5.73 IU/mL). Lp-PLA2 mass levels were positively correlated with body mass index, blood pressure changes, total cholesterol, triglyceride, and very low-density lipoprotein and stroke risk (SR) percentage.

Conclusions

Patients on statins with ischemic stroke had low levels of Lp-PLA2 mass levels compared to nonstatins user with ischemic stroke. Lp-PLA2 mass levels were higher in men than women and correlated with lipid profile and SR in patients with ischemic stroke.

Antiplatelet therapy for peripheral artery disease

Atherosclerotic cardiovascular (CV) disease represents one of leading cause of mortality and morbidity in Western countries. An increased risk of CV events was identified in patients with peripheral arterial diseases (PADs), which include all arterial diseases, other than coronary arteries and the aorta. In particular, lower extremity artery disease (LEAD) and/or carotid artery disease present growing incidence in general population and a consequent increase in mortality and morbidity. Medical treatment, including antiplatelet therapy, is a cornerstone in management of these patients, even when they are treated with endovascular or surgical procedures. Despite their clinical relevance, data on optimal antiplatelet treatment in this clinical setting are lacking and often derived from clinical trials on coronary artery disease and by subgroups analysis. The purpose of this review is to examine the available data from registries, randomized trials and meta-analysis on antiplatelet treatment in patients with LEAD and carotid stenosis with the aim to provide evidence to support clinical decision making.

Does Antiplatelet Therapy during Bridging Thrombolysis Increase Rates of Intracerebral Hemorrhage in Stroke Patients?

Background

Symptomatic intracerebral hemorrhage (sICH) after bridging thrombolysis for acute ischemic stroke is a devastating complication. We aimed to assess whether the additional administration of aspirin during endovascular intervention increases bleeding rates.

Methods

We retrospectively compared bleeding complications and outcome in stroke patients who received bridging thrombolysis with (tPA+ASA) and without (tPA-ASA) aspirin during endovascular intervention between November 2008 and March 2014. Furthermore, we analyzed bleeding complications and outcome in antiplatelet naïve patients with those with prior or acute antiplatelet therapy.

Results

Baseline characteristics, previous medication, and dosage of rtPA did not differ between 50 tPA+ASA (39 aspirin naïve, 11 preloaded) and 181 tPA-ASA patients (p>0.05). tPA+ASA patients had more often internal carotid artery (ICA) occlusion (p<0.001), large artery disease (p<0.001) and received more often acute stenting of the ICA (p<0.001). 10/180 (5.6%) tPA-ASA patients and 3/49 (6.1%) tPA+ASA patients suffered a sICH (p = 1.0). Rates of asymptomatic intracerebral hemorrhage, systemic bleeding complications and outcome did not differ between both groups (p>0.1). There were no differences in bleeding complications and mortality among 112 bridging patients with antiplatelet therapy (62 preloaded, 39 acute administration, 11 both) and 117 antiplatelet naïve patients. In a logistic regression analysis, aspirin administration during endovascular procedure was not a predictor of sICH.

Conclusion

Antiplatelet therapy before or during bridging thrombolysis in patients with acute ischemic stroke did not increase the risk of bleeding complications and had no impact on outcome. This finding has to be confirmed in larger studies.

Long-term Comparative Outcomes of Carotid Artery Stenting Following Previous Carotid Endarterectomy vs De Novo Lesions

PURPOSE

To report the long-term outcomes of patients who underwent carotid artery stenting (CAS) for de novo carotid stenosis vs patients treated for restenosis after carotid endarterectomy (CEA).

METHODS

A retrospective review was conducted of all 385 patients (mean age 68.6±9.6 years; 231 men) who underwent 435 CAS procedures at a large tertiary care center between January 1999 and December 2013. For analysis, patients were stratified based on their lesion type [de novo (dn) vs post-CEA restenosis (res)] and subclassified by symptoms status [symptomatic (Sx) or asymptomatic (Asx)], creating 4 groups: (1) CAS-dn Asx, (2) CAS-dn Sx, (3) CAS-res Asx, and (4) CAS-res Sx. For the CAS-res group, the mean elapsed time from CEA to CAS was 72.4±63.6 months. Outcomes included target vessel reintervention (TVR) and in-stent restenosis (ISR), the latter defined by a carotid duplex ultrasound velocity >275 cm/s.

RESULTS

The main indication for initial carotid angiography with possible revascularization was severe carotid stenosis (≥70%-99% on duplex) in both CAS-dn and CAS-res groups (83.6% vs 83.7%, p=0.999). There were no significant differences in the percentage of patients with postintervention residual stenosis (<30%; 100% each arm) or complications between CAS-res vs CAS-dn: in-hospital stroke (1.4% vs 1.8%, respectively), myocardial infarction (0.9% vs 0%), or death (0.9% vs 0%). Mean follow-up was 62.4±45.6 months (median 53.5, range 1-180). Average clinical/TVR follow-up was greater for the CAS-res group (71.9±48.6 months) compared with 53.3±40.5 months for the CAS-dn group (p<0.001). Across the 4 study groups, there were no differences in freedom from ISR (p=0.174) or TVR (p=0.856). Multivariate analysis found peripheral vascular disease (PVD) as the sole ISR independent predictor [hazard ratio (HR) 1.92, 95% confidence interval (CI) 1.03 to 3.62, p=0.041], while significant predictors for TVR were age <65 years at the time of the procedure (HR 2.55, 95% CI 1.05 to 6.18, p=0.039) and PVD (HR 2.46, 95% CI 1.03 to 5.87, p=0.043).

CONCLUSION

The current study suggests that CAS is a feasible and durable therapeutic option for recurrent restenosis after CEA. Long-term outcomes were similar for patients treated for de novo lesions or post-CEA restenosis. Age and PVD appear to influence long-term CAS durability.

Carotid endarterectomy versus stenting: Does the flow really change? An Echo-Color-Doppler analysis

To assess potential hemodynamic differences after carotid endarterectomy (CEA) and carotid artery stenting (CAS) and their eventual impact on clinical management. Between July 2012 and October 2013 two groups of 30 patients each referred for CEA or CAS were prospectively enrolled in two tertiary hospital care centers. Pre-procedural imaging assessment of carotid artery disease was performed with Echo-Color-Doppler (ECD) and computed tomography angiography (CTA). ECD was repeated within 24 h and 1, 6 and 12 months after surgical/endovascular procedures. Peak systolic velocity (PSV) and end diastolic velocity (EDV) were assessed at two standard sites: common carotid artery (CCA) and distal internal carotid artery (ICA). Twenty-four hours ECD findings highly differ between the two populations. CCA PSV in the CEA and CAS groups was respectively 44.88 ± 9.16 and 69.20 ± 20.04 cm/s (p = 0.002); CCA EDV was 16.11 ± 2.29 and 19.13 ± 6.42 cm/s (p = 0.065); ICA PSV was 46.11 ± 7.9 and 94.02 ± 57.7 cm/s (p = 0.0012); ICA EDV was 20.22 ± 4.33 and 30.47 ± 18.33 cm/s (p = 0.025). One month, 6 months and 1 year findings confirmed the different trend in the two cohorts; in particular, at 1 year: CCA PSV was 50.94 ± 12.44 and 60.59 ± 26.84 cm/s (p = 0.181); CCA EDV was 17.11 ± 3.46 and 19 ± 16.35 cm/s (p = 0.634); ICA PSV was 51.66 ± 10.1 and 70.86 ± 20.64 cm/s (p = 0.014); ICA EDV was 25.05 ± 8.65 and 32.66 ± 13 cm/s (p = 0.0609). ECD follow-up of patients undergone CEA or CAS may play a critical role in the clinical management. Strict surveillance of blood flow velocities allows reducing false positive re-stenosis diagnosis and choosing the best anti-aggregation therapies. Within the first month CEA patients benefit from a lower risk condition in comparison with CAS patients, due to a significantly faster PSV drop; moreover, long-term CCA PSV after CEA could be used as a surrogate marker of neointima formation.

Antiplatelet effect of clopidogrel can be reduced by calcium-channel blockers

PURPOSE

Clopidogrel is metabolized by the hepatic cytochrome P450 (CYP) system into its active thiol metabolite. CYP3A4 is involved in the metabolism of both clopidogrel and dihydropyridine calcium channel blockers (CCBs). A few reports have suggested an inhibitory interaction between CCBs and clopidogrel. Accordingly, the aim of this study was to determine the effect of CCBs on the antiplatelet activity of clopidogrel by serial P2Y12 reaction unit (PRU) measurements.

MATERIALS AND METHODS

We assessed changes in antiplatelet activity in patients receiving both clopidogrel and CCBs for at least 2 months prior to enrollment in the study. The antiplatelet activity of clopidogrel was measured by VerifyNow P2Y12 assay in the same patient while medicated with CCBs and at 8 weeks after discontinuation of CCBs. After discontinuation of the CCBs, angiotensin receptor blockers were newly administered to the patients or dosed up for control of blood pressure.

RESULTS

Thirty patients finished this study. PRU significantly decreased after discontinuation of CCBs (238.1±74.1 vs. 215.0±69.3; p=0.001). Of the 11 patients with high post-treatment platelet reactivity to clopidogrel (PRU≥275), PRU decreased in nine patients, decreasing below the cut-off value in seven of these nine patients after 8 weeks. Decrease in PRU was not related to CYP2C19 genotype.

CONCLUSION

CCBs inhibit the antiplatelet activity of clopidogrel.

The current management of carotid atherosclerotic disease: who, when and how?

Ischaemic stroke represents a major health hazard in the western world, which has a severe impact on society and the health-care system. Roughly, 10% of all first ischaemic strokes can be attributed to significant atherosclerotic disease of the carotid arteries. Correct management of these lesions is essential in the prevention and treatment of carotid disease-related ischaemic events. The close relationship between diagnosis and medical and surgical management makes it necessary that all involved physicians and surgeons have profound knowledge of management strategies beyond their specific speciality. Continuous improvement in pharmacological therapy and operative techniques as well as frequently changing guidelines represent a constant challenge for the individual health-care professional. This review gives a thorough outline of the up-to-date evidence-based management of carotid artery disease and discusses its current controversies.

How Safe is Eptifibatide during Urgent Carotid Artery Stenting?

Background: Glycoprotein IIB/IIIA inhibitors are occasionally utilized during carotid artery stenting (CAS) in the presence or absence of a visualized intra-operative thrombus.

Objective: We assess the hemorrhagic and clinical outcomes associated with the use of eptifibatide during CAS.

Methods: A retrospective analysis of prospectively collected data on patients with the diagnosis of carotid artery stenosis underwent CAS in a single center. We identified those who received intravenous eptifibatide intra-operatively and compared to the rest of the cohort. Hemorrhagic outcomes included intracerebral hemorrhage (ICH) or groin hematoma that occurred during the hospital stay.

Results: In this analysis, 81 patients had CAS during a 3-year span; 16 of those had received 15 mg of intravenous eptifibatide intra-operatively. The mean age of the treated and untreated patients was similar (65.6 ± 13.4 versus 65.4 ± 10.2; P = 0.13). One patient (1.2%) in this series had ICH in the perioperative period that occurred in the non-eptifibatide group. Five patients (6.2%) in this series had groin hematoma; only one in the non-eptifibatide group required surgical repair. No mortality was reported and clinical outcomes including discharge modified Rankin scale, NIH stroke scale, as well as discharge destination were similar in both groups. A stratified analysis among those who underwent an urgent CAS showed no significant differences in the risks of hemorrhages or any clinical outcome (P > 0.05).

Conclusion: The use of eptifibatide during CAS is safe. The risk of any hemorrhagic complication is rare in this series; however, a prospective study to validate this observation will be helpful.

Diagnosis of and treatment for symptomatic carotid stenosis: an updated review

Carotid stenoses of ≥50% account for about 15-20% of strokes. Their degree may be moderate (50-69%) or severe (70-99%). Current diagnostic methods include ultrasound, MR- or CT-angiography. Stenosis severity, irregular plaque surface, and presence of microembolic signals detected by transcranial Doppler predict the early recurrence risk, which may be as high as 20%. Initial therapy comprises antiplatelets and statins. Benefit of revascularization is greater in men, in older patients, and in severe stenosis; patients with moderate stenoses may also profit particularly if the plaque has an irregular aspect. An intervention should be performed within <2 weeks. In large randomized studies comparing endarterectomy and stenting, endovascular therapy was associated with a higher risk of periprocedural stroke, yet in some studies, with a lower risk of myocardial infarction and of cranial neuropathy. These trials support endarterectomy as the first choice treatment. Risk factors for each of the two therapies have been indentified: coronary artery disease, neck radiation, contralateral laryngeal nerve palsy for endarterectomy, and, elderly patients (>70 years), arch vessel tortuosity and plaques with low echogenicity on ultrasound for carotid stenting. Lastly, in direct comparisons, a contralateral occlusion increases the risk of periprocedural complications in both types of treatment.

Prevention of stent thrombosis with reduced dose of prasugrel in two patients undergoing treatment of cerebral aneurysms with pipeline embolisation devices

Prevention of intracranial stent thrombosis with dual-antiplatelet therapy is widely used in neuroendovascular procedures. However, the rising incidence of inadequate platelet inhibition with clopidogrel may increase complications following stent placement, especially with newer devices that possess a larger total metal surface area. While there are recent reports of prasugrel as an alternative to clopidogrel, there is no clinical evidence in neurointerventional patients regarding the use of a lower maintenance dose as an alternative strategy to gain adequate platelet inhibition while possibly reducing the risk of bleeding. We present 6-month efficacy and safety outcomes of two patients undergoing elective pipeline embolisation that were found to have inadequate platelet response to clopidogrel and subsequently transitioned to prasugrel 5 mg daily for the prevention of stent thrombosis.

Cilostazol prevents progression of asymptomatic carotid artery stenosis in patients with contralateral carotid artery stenting

BACKGROUND AND PURPOSE

The progression of atherosclerosis is related to various factors. Although antiplatelet therapy is used for the management of acute ischemic stroke and for the prevention of recurrent stroke, the antiplatelet agent cilostazol may also reduce restenosis after stent implantation in any vessel. This study was performed to assess the impact of cilostazol on plaque progression in the carotid artery contralateral to a stented artery.

MATERIALS AND METHODS

Ninety-five patients who underwent contralateral CAS who also had ipsilateral 0%-79% ICS were enrolled. ICS was assessed by duplex sonography every 6 months and by MR imaging/angiography, and digital subtraction angiography if necessary, every 12 months according to the NASCET method. Patient age, sex, past history, and perioperative medical conditions were recorded.

RESULTS

While 22.1% of patients experienced disease progression, symptomatic ipsilateral stroke occurred in only 1.1% of patients over 36.2 ± 18.8 months. On multivariate analysis, precarotid stenosis (HR per 10% increase, 2.08; 95% CI, 1.43-3.05; P < .001) and cilostazol use (HR 0.16; 95% CI, 0.03-0.85; P = .03) were independent predictors for the progression of ICS.

CONCLUSIONS

A higher degree of initial stenosis is associated with progression of asymptomatic ICS. Cilostazol may reduce the rate of disease progression in patients with asymptomatic ICS.

Carotid artery stenting in acute stroke

OBJECTIVES

The purpose of this study is to demonstrate the technical success of carotid artery stenting in acute extracranial internal carotid artery (ICA) occlusion as well as the benefit in clinical outcome.

BACKGROUND

Stroke caused by acute occlusion of the ICA is associated with a significant level of morbidity and mortality. For this type of lesion, treatment with standard intravenous thrombolysis alone leads to a good clinical outcome in only 17% of the cases, with a death rate as high as 55%. Recanalization of the occluded ICA can lead to an improvement in acute symptoms of stroke, prevent possible deterioration, and reduce long-term stroke risk. At present, there is no consensus treatment for patients with acute ischemic stroke presenting with severe clinical symptoms due to atherosclerotic occlusion of the extracranial ICA.

METHODS

Carotid artery stenting was performed in 22 patients with acute atherosclerotic extracranial ICA occlusion within 6 h of stroke symptom onset. In 18 patients, there was an additional intracranial occlusion at the level of the terminal segment of the ICA (n = 4) and at the level of the middle cerebral artery (n = 14). Intracranial occlusions were either treated with the Penumbra system or the Solitaire stent-based recanalization system, or a combination of mechanical recanalization and intra-arterial thrombolysis. Recanalization results were assessed by angiography immediately after the procedure. The neurologic status was evaluated before and after the treatment with a follow-up as long as 90 days using the National Institutes of Health Stroke Scale and the modified Rankin Scale.

RESULTS

Successful revascularization of extracranial ICA with acute stent implantation was achieved in 21 patients (95%). There was no acute stent thrombosis. After successful recanalization of the origin of the ICA, the intracranial recanalization with Thrombolysis In Myocardial Infarction flow grade 2/3 was achieved in 11 of the 18 patients (61%). The overall recanalization rate (extracranial and intracranial) was 14 of 22 patients (63%). Nine patients (41%) had a modified Rankin Scale score of ≤2 at 90 days. The mortality rate was 13.6% at 90 days.

CONCLUSIONS

Carotid artery stenting in acute atherosclerotic extracranial ICA occlusion with severe stroke symptoms is feasible, safe, and useful within the first 6 h after symptom onset.

Carotid angioplasty and stenting: evolution and current status

The management of carotid stenosis is in evolution. Carotid endarterectomy has been the gold standard for the treatment of carotid stenosis for many years. However, recently, carotid angioplasty and stenting has emerged as a feasible and relatively safe management alternative. The appropriate clinical setting for its preferential use over carotid endarterectomy continues to be the subject of ongoing clinical trials. In this article, we review the evolution of carotid angioplasty and stenting, the evidence behind the current indications, and limitations of this procedure, as well as provide an overview of preprocedural evaluations and periprocedural management.

Carotid artery stenting: what you need to know

Carotid stenting has become an accepted alternative in patients with carotid stenosis. The purpose of this article is to review the relevant trials, describe the different devices available for stenting, the devices for cerebral protection, as well as describe techniques and tricks for successful carotid artery stenting. Understanding how to appropriately preoperatively evaluate patients and intra- and postoperative procedures, carotid artery stenting can be a safe procedure.

Aspirin dosing for the prevention and treatment of ischemic stroke: an indication-specific review of the literature

OBJECTIVE

To evaluate the efficacy of aspirin for the treatment and prevention of ischemic stroke and identify the minimum dose proven to be effective for each indication.

DATA SOURCES

PubMed and MEDLINE searches (up to January 2010) were performed to identify primary literature, using search terms including aspirin, stroke prevention, acute ischemic stroke, acetylsalicylic acid, atrial fibrillation, myocardial infarction, and carotid endarterectomy. Additionally, reference citations from publications identified were reviewed.

STUDY SELECTION AND DATA EXTRACTION

Articles published in English were evaluated and relevant primary literature evaluating the efficacy of aspirin in the prevention of stroke was included in this review.

DATA SYNTHESIS

Antiplatelet therapy is the benchmark for the prevention of ischemic stroke. Aspirin has been proven to prevent ischemic stroke in a variety of settings. Despite the frequency at which aspirin continues to be prescribed in patients at risk of ischemic stroke, there remains confusion in clinical practice as to what minimum dose is required in various at-risk patients. A thorough review of the primary literature suggests that low-dose (50-81 mg daily) aspirin is insufficient for some indications. Acute ischemic stroke treatment requires 160-325 mg, while atrial fibrillation and carotid arterial disease require daily doses of 325 and 81-325 mg, respectively.

CONCLUSIONS

Available evidence suggests that aspirin dosing must be individualized according to indication. Recommendations provided by national guidelines at times recommend lower doses of aspirin than have been proven effective. Higher doses are indicated for stroke prevention in atrial fibrillation (325 mg) and acute ischemic stroke patients (160-325 mg). Aspirin has not yet been proven effective for primary prevention of strokes in men, and a minimum dose for these patients cannot be determined from the available data.

Experimental evaluation of a new antithrombogenic stent using ion beam surface modification

A new antithrombogenic stent using ion beam surface modification nanotechnology was evaluated. The ion stent is being developed to inhibit acute and chronic stent-related thrombosis. Thirty self-expanding mesh stents were fabricated from Ti-Ni metal wires with a dimension of 4 mm (diameter) x 25 mm (length) x 0.15 mm (thickness). Twenty stents were coated with type I collagen and irradiated with a He(+) ion beam at an energy of 150 keV with fluences of 1 x 10(14) ions/cm(2) (ion stent group). Ten stents had no treatment (non-ion stent group). The self-expanding stents were implanted into the right and left peripheral femoral arteries of 15 beagle dogs (vessel diameter approximately 3 mm) via a 6Fr catheter under fluoroscopic guidance. Heparin (100 units/kg) was administered intravenously before implantation. Following stent implantation, no antiplatelet or anticoagulant drugs were administered. The 1-month patency rate for the non-ion stent group was 10% (1/10), and for the ion stent group it was 80% (16/20) with no anticoagulant or antiplatelet drugs given after stent implantation (P = 0.0004 by Fisher's exact test). Ten stents remain patent after 2 years in vivo with no anticoagulant or antiplatelet drugs. These results indicate that He(+) ion-implanted collagen-coated Ti-Ni self-expanding stents have excellent antithrombogenicity and biocompatibility. This ion stent is promising for coronary and cerebral stent applications.

Serial Changes of Circulating Platelet Activation Markers after Carotid Artery Stenting

We investigated serial changes of circulation platelet activation markers in 40 patients undergoing carotid artery stenting under the protection of dual antiplatelet therapy and filter devices. Monocyte-platelet aggregates and PAC-1 (a marker specific for activated glycoprotein IIb/IIIa) analyzed by flow cytometry were determined in patients with symptomatic stenosis undergoing elective carotid artery stenting. Blood samples were obtained immediately before stent implantation and 0.5 hours, 18 hours, and 6 days after the procedure, respectively. All patients were already on dual antiplatelet therapy of aspirin and clopidogrel before carotid artery stenting, and all were stented with embolic protection devices. Both circulation monocyte-platelet aggregates and PAC-1 did not change significantly at the various time points after the procedure. Serial changes of monocyte-platelet aggregates and PAC-1 analyzed by flow cytometry fail to indicate the occurrence of platelet activation after carotid artery stenting under the treatment with dual antiplatelet therapy before carotid artery stenting and the application of embolic protection devices during the procedure.

Rescue use of tirofiban for acute carotid in-stent thrombosis

Carotid artery stenting is widely performed for extracranial carotid artery stenosis. In-stent thrombosis is a rare but potentially devastating complication. We present a case of acute in-stent thrombosis immediately following stent insertion and post-balloon dilatation in a 64-year-old male. Thrombosis was successfully treated by intravenous tirofiban, a glycoprotein IIb/IIIa receptor inhibitor.

Carotid endarterectomy versus angioplasty/stenting for carotid stenosis

Carotid occlusive disease remains an important cause of ischemic stroke. The results of large, randomized clinical trials have established the benefit of surgical revascularization in selected patients with symptomatic or asymptomatic carotid stenosis. The introduction of balloon angioplasty and stenting of the extracranial carotid artery as a potential alternative to surgery has been received with enthusiasm by patients and physicians alike. Whether or not this enthusiasm is fully justified has yet to be determined. This article reviews published data regarding the safety and clinical efficacy of carotid angioplasty and stenting. Particular focus is directed towards results from recently completed and ongoing prospective comparative trials of endarterectomy and carotid angioplasty and stenting.

Antiplatelet agents for stroke prevention following transient ischemic attack

Regardless of extent or duration of acute effects, transient ischemic attack (TIA) is a marker for cerebrovascular ischemia and carries risk for secondary stroke comparable to that associated with ischemic stroke. Pharmacologic and nonpharmacologic interventions aimed at reducing risk of secondary stroke should be implemented as soon as possible after characterization of the initial event. Medical strategies for secondary prevention include modifying general cardiovascular risk factors but are centered on the specific reduction of stroke risk by antiplatelet agents. Aspirin and clopidogrel have each demonstrated efficacy in reducing secondary event risk; however, clopidogrel has not been shown specifically to prevent secondary events in patients who have had a TIA or stroke. Combination therapy using aspirin plus dipyridamole is the only combination approach to demonstrate additive benefit that is significantly greater than that conferred by aspirin. In contrast, the combination of clopidogrel plus aspirin has not demonstrated significant benefit over monotherapy with either agent and has been associated with increased risk of bleeding episodes.

Monitoring antiplatelet therapy during peripheral vascular and coronary interventions

Platelets play a central role in the initiation and propagation of thrombus formation. The use of antiplatelet and antithrombotic medications during peripheral vascular and coronary interventions helps reduce the likelihood of intravascular thrombus formation and adverse ischemic events. As formation of intravascular thrombus and subacute stent thrombosis are thrombin- and platelet-mediated phenomenon, achieving optimal activated clotting time and platelet inhibition (PI) during the interventional procedure is critical. However, as a quick and easy measure of platelet function has previously not been available in the interventional laboratory, cardiovascular interventions are routinely performed after administration of oral or intravenous antiplatelet agents without evaluating platelet function. Recently, point-of-care rapid platelet function assays have become available that allow quick and reproducible measure of platelet function in the interventional laboratory after administration of aspirin, thienopyridines, and glycoprotein IIb/IIIa inhibitors. Though PI can now be routinely measured during vascular interventions, considerable inconsistencies exist in the management of patients based on these results. We present an algorithm for the management of antiplatelet therapy during cardiovascular interventions based on rapid evaluation of platelet function in the interventional laboratory.

Exclusion of Atherosclerotic Plaque from the Circulation Using Stent-Grafts: Alternative to Carotid Stenting with a Protection Device?

PURPOSE

To retrospectively assess the feasibility, safety, and clinical mid-term outcome of patients undergoing carotid artery stenting with stent-grafts.

METHODS

Over a 4 year period stent-grafts were used in the endovascular treatment of symptomatic internal carotid artery stenosis in 12 patients (2 women, 10 men, aged 47-83 (mean 64) years). Protection devices were not used. Possible microembolic complications were evaluated by magnetic resonance imaging (MRI) examinations of the brain before and the day after the procedure in all patients. Mean follow-up was 22 months (range 1-42 months), by Doppler ultrasonography and conventional angiography as well as clinical examination.

RESULTS

The technical success rate was 100%. A total of 13 coronary stent-grafts were used. The mean stenosis rate (in terms of diameter) was 85% and the mean length of stent-grafts used was 20.9 mm. The mean diameter to which the stent-grafts were dilated was 4.66 mm. In-hospital complications occurred in 1 patient who suffered a minor femoral access hematoma that did not require transfusion or surgical decompression. Post-stenting diffusion-weighted MRI revealed several ipsilateral silent microemboli in only 1 case, which was completely asymptomatic. Two patients had a major stroke after 2 years of follow-up. Restenosis was found in 2 patients who underwent successful balloon dilatation followed by placement of a self-expandable bare stent within the stent-grafts.

CONCLUSIONS

Stent-grafts may prevent microembolic complications during stenting of atherosclerotic carotid lesions in selected cases, offering immediate exclusion of the atherosclerotic lesion from the circulation by pressing the plaque against the vessel wall. Comparative, randomized studies in larger series of patients are needed with carotid-dedicated stent-graft designs.