Incidence Of New Ischemic Lesions Research Articles

Absence of the Anterior Communicating Artery on Selective MRA is Associated with New Ischemic Lesions on MRI after Carotid Revascularization.

ICA-selective MRA using a pencil beam presaturation pulse can accurately visualize anterior communicating artery flow. We evaluated the impact of anterior communicating artery flow on the perioperative hemodynamic status and new ischemic lesions after carotid revascularization. Eighty-three patients with carotid artery stenosis were included. We assessed anterior communicating artery flow using ICA-selective MRA. The preoperative hemodynamic status was measured using SPECT. We also measured the change in regional cerebral oxygen saturation after temporary ICA occlusion. New ischemic lesions were evaluated by DWI on the day after treatment. Anterior communicating artery flow was detected in 61 patients, but it was not detected in 22 patients. Preoperative cerebrovascular reactivity was significantly higher in patients with (versus without) anterior communicating artery flow with a mean peak systolic velocity of ≥200 cm/s (39.6% [SD, 23.8%] versus 25.2% [SD, 16.4%]; P = .030). The decrease in mean regional cerebral oxygen saturation was significantly greater in patients without (versus with) anterior communicating artery flow (8.5% [SD, 5.6%] versus 3.7% [SD, 3.8%]; P = .002). New ischemic lesions after the procedure were observed in 23 patients. The multivariate logistic regression analysis revealed that anterior communicating artery flow (OR, 0.07; 95% CI, 0.012-0.45; P = .005) was associated with new ischemic lesions. The absence of anterior communicating artery flow influenced the perioperative hemodynamic status in patients with carotid stenosis and was associated with an increased incidence of new ischemic lesions after carotid revascularization.

Anemia and risk of periprocedural cerebral injury detected by diffusion-weighted magnetic resonance imaging in patients undergoing transcatheter aortic valve replacement.

Anemia is prevalent in patients undergoing transcatheter aortic valve replacement (TAVR) and has been linked to impaired outcomes after the procedure. Few studies have evaluated the impact of anemia and new ischemic lesions post TAVR. We prospectively enrolled 158 patients who received TAVR in our center. Anemia was defined according to the World Health Organization criteria as hemoglobin <12 g/dL in women and <13 g/dL in men. All patients underwent diffusion-weighted magnetic resonance imaging (DW-MRI) procedure before and within 4-7 days after TAVR. Anemia was present in 85 (53.8%) patients who underwent TAVR, and 126 (79.7%) patients had 718 new DW-MRI positive lesions with a mean of 4.54±5.26 lesions per patient. The incidence of new ischemic lesions was 81.2% in patients with anemia versus 78.1% in patients without anemia (P=0.629). Moreover, anemic patients had bigger total volume/lesions in the anterior cerebral artery/middle cerebral artery (ACA/MCA) and MCA regions compared to the non-anemic patients (31.89±55.78 mm3 vs. 17.08±37.39 mm3, P=0.049; and 54.54±74.72 mm3 vs. 33.75±46.03 mm3, P=0.034). Anemia was independently associated with the volume/lesion in the ACA/MCA (β=16.796, 95% confidence interval [95% CI] 2.001 to 31.591, P=0.026) and in the MCA zone (β=0.020, 95% CI 0.001 to 0.040, P=0.041). Patients with pre-procedural anemia may have bigger total volume/lesions in the ACA/MCA and MCA regions compared to the non-anemic patients. Whether the consequences of bigger total volume/lesions impact neurological and cognitive outcomes remains to be investigated.

Apixaban for treatment of embolic stroke of undetermined source (ATTICUS) randomized trial – update of patient characteristics and study timeline after interim analysis

Abstract Background Secondary prevention after embolic stroke of undetermined source (ESUS) has not yet been established. ESUS is associated with high risk of recurrent ischemic stroke and clinically silent ischemic lesions. Secondary prevention with aspirin is the current standard therapy in ESUS patients, despite high prevalence of occult atrial fibrillation (AF). Purpose To determine whether the direct oral factor Xa inhibitor apixaban, started within 28 days after index stroke, is superior to aspirin in preventing new ischemic lesions in subjects with remote cardiac monitoring. Primary endpoint was detection of new ischemic lesions in flair and diffusion-weighted (DWI) MR imaging at 12 months follow-up. Methods The study enrolled ESUS patients with risk profile for cardiac thromboembolism (i.e., left atrium (LA) size &amp;gt;45 mm, spontaneous echo contrast in LA appendage, LA appendage flow velocity ≤0.2 cm/s, atrial high rate episodes, CHA2DS2-Vasc score ≥4, patent foramen ovale). Patients were randomized 1:1 into the aspirin and apixaban arms. Study drug was initiated within 3–28 days after minor/moderate stroke and 14–28 days after major stroke. MRI (Flair/DWI) was conducted within 7 days of AF detection by remote cardiac monitors and at 12 months. ClinicalTrials.gov Identifier: NCT02427126. Funding: The trial is supported by BMS-Pfizer Alliance. Results Enrollment was stopped after interims analysis (including 200 patients) due to futility. Overall, 373 patients were screened with 353 being enrolled (178 and 175 in apixaban and ASA arms, respectively). So far, 130 (73.0%) and 120 (68.6%) subjects from apixaban and ASA arms, respectively, completed the study. 2% death, 1.7% withdrawal, and 1.7% were lost to follow-up. 3.9% did not completed the study for other reasons. Mean age of the ATTICUS population was 68.5 years with 51% males. 80% of the subjects suffered from hypertension. Mean systolic blood pressure at enrollment was 132 mmHg, BMI was 27.7, and CHA2DS-VASc-Score was 4.9. So far, adverse events (AE) occurred in 63% of the subjects, 30% was documented as severe. 6.8% cases of recurrent ischemic stroke and no case of hemorrhagic stroke were reported. Only 1 case of severe bleeding was reported in the aspirin arm. Newly detected AF was reported in 80 patients (23%), 42 occurring in the aspirin arm. As required by protocol, latter were immediately switched from aspirin to apixaban. Due to ongoing data clearing, numbers and % will change until presentation. Conclusions In contrast to the recently published NAVIGATE and RESPECT ESUS trials, patients enrolled in ATTICUS need to exhibit additional AF predicting factors. Furthermore, mandatory cardiac remote monitoring will help to elucidate the impact of AF and the effects of early oral anticoagulation with apixaban compared to antiplatelet therapy with aspirin on the incidence of new ischemic lesions after ESUS. Preliminary data will be presented and discussed in the context of current literature. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): The trial is supported by BMS-Pfizer Alliance.

Double Layer Micromesh Stents Versus Closed Cell Stents for the Endovascular Treatment of Carotid Stenosis in the Current Era

Introduction: Although several randomized control studies showed increase incidence of adverse neurological events in the 30-day post-procedure outcomes in patients with carotid stenosis treated with carotid stenting (CAS) versus endarterectomy (CEA), recent guidelines suggests promising results with CAS in high volume centres with expert surgeons1. Based on this findings, companies that produce medical devices are multiplying their efforts to design new stents structure that can better protect carotid plaque during carotid stenosis endovascular treatment to avoid plaque prolapse or micro-debris embolization. The role of real effectiveness of Anti-platelet therapy on neurological complication of CAS remains unclear. The aim of this study is to examine the incidence of new ischaemic lesions, stroke o TIA, in patients treated in our centre using a new double-layer micromesh stent versus a closed cell stent. Methods: A Prospective randomized 1:1 trial was conducted from 1st January 2016 on going to compare the outcomes of carotid stenosis treatment with double-layer micromesh stents VS closed cell stents. The primary end point was the occurrence of death and neurological adverse events (TIA /Stroke) within 30 days. Secondary end point was the occurrence major adverse cardiovascular events (MACEs), defined as MI or severe arrhythmias. 88 patients were enrolled in both arm of the study. A distal protection device was used in all cases. All patient were treated preoperatively, and for 3 months post-operatively, with double anti-aggregation therapy and underwent multiplate platelet function testing using ADP test in order to assess clopidogrel resistance and therefore shifted to ticagrelor antiplatelet therapy. Statistical analysis was conducted with SAS software, version 9.4 (SAS Institute, Inc., Cary, NC). Results: There was 41 females (46,6%) and 47 males (53,4%) In group 1 and 38 females (43.2%) and 50 males in group 2 (56,8%). No stroke or death was observed in both groups of patients. No statistical differences were observed in terms of minor neurological adverse events (TIA) within 30 days: 2 (2.7%) patient experienced peri-operative TIA, with prompt recovery, and no new findings were seen in the neuroimaging in both arm of the trial. Patients symptomatic for pre-operative TIA within 30-days were treated in 2 cases (2.7%) in Group A and in 3 case (3.4%) in group B with no neurological post-operative complications. In terms of major adverse cardiovascular events (MACEs) no MI were observed in both groups. No statistical differences were defined for severe arrhythmias compared intra-operatively in 5 patients (5.7%) in group 1 vs 2 patients (2.7%) in group B (P 0.43). Overall the to groups, 20% of the patients showed high residual platelet reactivity after clopidogrel therapy ant thus shifted to ticagrelor for effective double anti-platelet therapy. Conclusion: Primary Carotid stenting with double-layer micromesh stents showed safe and feasible results. A tendency of a slightly higher incidence of intraoperative severe arrhythmias with the double layer micromesch stent may be due to higher radial force caused by the stent structure. Real effective antiplatelet therapy may partially explain similar results with both types of stents for the treatment of internal carotid artery stenosis.

Silent cerebral embolism after carotid endarterectomy: a two-center experience

Objectives. Carotid endarterectomy (CEA) is considered the most effective treatment for stroke prevention in patients with critical carotid stenosis. The incidence of new ischemic lesions ranges from 0% to 33% at diffusion-weighted magnetic resonance imaging (DW-MRI) after CEA in previous studies. We determined the rate of silent cerebral embolism in CEA patients by DW-MRI in this study. Methods. This study was conducted between January 2016 and April 2016 in two centers. Thirty-five consecutive patients (three with bilateral) with 38 CEAs were included in the study. There were no new postoperative symptoms in all patients. Preoperative and postoperative brain DW-MRIs were performed within one day preoperatively and second day postoperatively. Two DW-MRIs were screened and compared in terms of newly occurring lesions. Thus, we attempted to find the rate of silent cerebral embolism. Results. New brain lesions were detected in six (6/38 CEAs; 15.8%) cases with unilateral CEAs. All of these lesions were ischemic. In five cases, new lesions were located within the operated carotid artery territory (ipsilateral parietal lobe). However, in one case, a new lesion was located outside of the operated carotid artery territory (ipsilateral occipital lobe). Thirty-day morbidity and mortality rates were 0% and 2.85% (1/35), respectively. Conclusion. Silent cerebral embolisms may frequently occur during postoperative period in CEA patients. Even if these lesions are asymptomatic, we have to be rigorous to avoid microembolism during all stages during surgery.

SONOlysis in prevention of Brain InfaRctions During Internal carotid Endarterectomy (SONOBIRDIE) trial \u2013 study protocol for a randomized controlled trial

BackgroundCarotid endarterectomy (CEA) is a beneficial procedure for selected patients with an internal carotid artery (ICA) stenosis. Surgical risk of CEA varies from between 2 and 15%.The aim of the study is to demonstrate the safety and effectiveness of sonolysis (continual transcranial Doppler monitoring, TCD) using a 2-MHz diagnostic probe with maximal diagnostic energy on the reduction of the incidence of stroke, transient ischemic attack (TIA) and brain infarction detected using magnetic resonance imaging (MRI) by the activation of the endogenous fibrinolytic system during CEA.Methods/designDesign: a multicenter, randomized, double-blind, sham-controlled trial.Scope: international, multicenter trial for patients with at least 70% symptomatic or asymptomatic ICA stenosis undergoing CEA.Inclusion criteria: patients with symptomatic or asymptomatic ICA stenosis of at least 70% are candidates for CEA; a sufficient temporal bone window for TCD; aged 40–85 years, functionally independent; provision of signed informed consent.Randomization: consecutive patients will be assigned to the sonolysis or control (sham procedure) group by computer-generated 1:1 randomization. Prestudy calculations showed that a minimum of 704 patients in each group is needed to reach a significant difference with an alpha value of 0.05 (two-tailed) and a beta value of 0.8 assuming that 10% would be lost to follow-up or refuse to participate in the study (estimated 39 endpoints).Endpoints: the primary endpoint is the incidence of stroke or TIA during 30 days after CEA and the incidence of new ischemic lesions on brain MRI performed 24 h after CEA in the sonolysis and control groups. Secondary endpoints are occurrence of death, any stroke, or myocardial infarction within 30 days, changes in cognitive functions 1 year post procedure related to pretreatment scores, and number of new lesions and occurrence of new lesions ≥0.5 mL on post-procedural brain MRI.Analysis: descriptive statistics and linear/logistic multiple regression models will be performed. Clinical relevance will be measured as relative risk reduction, absolute risk reduction and the number needed to treat.DiscussionReduction of the periprocedural complications of CEA using sonolysis as a widely available and cheap method may significantly increase the safety of CEA and extend the indication criteria for CEA.Trial registrationClinicalTrials.gov, NCT02398734. Registered on 20 March 2015.

Hemodynamic Tandem Intracranial Lesions on Magnetic Resonance Angiography in Patients Undergoing Carotid Endarterectomy.

BackgroundHemodynamic tandem intracranial lesions (TILs) on intracranial magnetic resonance angiography, which develop flow dependently, have been overlooked clinically in patients undergoing carotid endarterectomy. As they represent severe baseline hemodynamic compromise at the segment, they may be associated with distinctive clinical outcomes.Methods and ResultsWe assessed 304 consecutive carotid endarterectomy cases treated over 3 years. Included cases had both preoperative and postoperative intracranial 3‐dimensional time‐of‐flight magnetic resonance angiography, of which signal intensities are flow dependent, and postoperative diffusion‐weighted imaging (≤3 days following carotid endarterectomy). Preoperative TILs in the ipsilateral intracranial arteries were evaluated by the presence of nonexclusive components: focal stenosis (>50%), diffuse stenosis (>50%), and decreased signal intensities (>50%). The components showing postoperative normalization were considered hemodynamic. TILs with hemodynamic components were defined as hemodynamic TILs, while others as consistent TILs. Baseline characteristics and postoperative outcomes were analyzed among 3 groups: no TILs, consistent TILs, and hemodynamic TILs. Preoperative TILs were identified in 104 (34.2%) cases; 54 (17.8%) had hemodynamic components. Diffuse stenosis and decreased signal intensities were usually reversed postoperatively. Patients with hemodynamic TILs tended to have severe proximal carotid stenosis and recent strokes (≤14 days). For the outcome, hemodynamic TILs were independently associated with the advent of postoperative ischemic lesions on diffusion‐weighted imaging (odds ratio: 2.50; 95% CI, 1.20–5.20).ConclusionsIn patients undergoing carotid endarterectomy, a significant number of preoperative TILs demonstrated hemodynamic components, which were reversed postoperatively. The presence of such components was distinctively associated with the postoperative incidence of new ischemic lesions.

Incidence of New Ischaemic Brain Lesions After Carotid Artery Stenting with the Micromesh Roadsaver Carotid Artery Stent: A Prospective Single-Centre Study.

Several randomized trials of patients with carotid stenosis show increased adverse neurological events with stenting versus endarterectomy in the 30-day post-procedure. This study examines the incidence of new ischaemic lesions in patients treated in our centre using the new Roadsaver stent. Between September 2015 and January 2016, 23 consecutive patients (age 74.3±7.3years, 17.4% female) underwent carotid artery stenting with the Roadsaver stent, a nitinol double-layer micromesh device. A distal protection device was used in all cases. Diffusion-weighted magnetic resonance imaging was performed 24h before, and 24h and 30days after the procedure. The 24-h post-procedure imaging showed 15 new ipsilateral ischaemic lesions in 7 (30.4%) patients: median volume 0.076cm3 (interquartile range 0.065-0.146cm3). All lesions were asymptomatic. The 30-day imaging showed complete resolution of all lesions and no new ischaemic lesions. Follow-up clinical and ultrasound examinations at 30days and 6months recorded no adverse cardiac or cerebrovascular events. Protected stenting with micromesh Roadsaver stent showed good safety and efficacy in the treatment of carotid stenosis, with a low incidence of delayed embolic events and new ipsilateral ischaemic brain lesions. These preliminary results are encouraging, but need to be confirmed with larger populations.

New cerebral lesions at magnetic resonance imaging after carotid artery stenting versus endarterectomy: an updated meta-analysis.

BackgroundCarotid endarterectomy (CEA) or stenting (CAS) are associated with a relatively low rate of clinical events, but diffusion-weighted imaging (DWI) is increasingly being used to compare the incidence of new ischemic lesions. Therefore, we conducted an updated meta-analysis on the occurrence of post-procedural new DWI lesions after CAS versus CEA.Methods and ResultsMEDLINE, Cochrane, ISI Web of Science and SCOPUS databases were searched and 20 studies (2 randomized and 18 non-randomized) with a total of 2104 procedures (CAS = 989; CEA = 1115) were included. The incidence of new DWI cerebral lesions was significantly greater after CAS than CEA (40.3% vs 12.2%; 20 studies; 2104 patients; odds ratio [OR] 5.17; 95% confidence interval [CI], 3.31-8.06; p<0.00001). Also peri-procedural stroke (17 studies; 1833 patients; OR 2.01; 95% CI, 1.14-3.55; p=0.02) and stroke or TIA (17 studies; 1833 patients; OR 2.40; 95% CI, 1.42-4.08; p=0.001) were significantly increased after CAS. This latter clinical advantage in the CEA group over CAS was tempered when CEA procedures were performed with shunting in all instead of selective shunting or when CAS was performed with only closed cell stents instead of both closed and open cell stents, however, no significant differences between subgroups emerged.ConclusionsCAS is associated with an increased incidence of post-procedural brain DWI lesions. This greater amount of ischemic burden may also reflect a higher rate of cerebral events after CAS. However, whether recent technical advances mainly for CAS could potentially reduce these ischemic events still remains to be evaluated.

Cerebral embolic lesions detected with diffusion-weighted magnetic resonance imaging following carotid artery stenting: a meta-analysis of 8 studies comparing filter cerebral protection and proximal balloon occlusion.

The aim of this meta-analysis was to evaluate and compare the efficacy of the 2 different neuroprotection systems in preventing embolization during carotid artery stenting (CAS), as detected by diffusion-weighted magnetic resonance imaging (DW-MRI). Data from randomized and nonrandomized studies comparing both types of embolic protection devices revealed contrasting evidence about their efficacy in neuroprotection, as assessed by the incidence of new ischemic lesions detected by DW-MRI. Eight studies, enrolling 357 patients, were included in the meta-analysis. Our study analyzed the incidence of new ischemic lesions/patient, comparing filter cerebral protection and proximal balloon occlusion. Following CAS, the incidence of new ischemic lesions/patient detected by DW-MRI was significantly lower in the proximal balloon occlusion group (effect size [ES]:-0.43; 95% confidence interval [CI]:-0.84 to-0.02, I(2)= 70.08, Q= 23.40). Furthermore, following CAS, the incidence of lesions at the contralateral site was significantly lower in the proximal protection group (ES:-0.50; 95% CI:-0.72 to-0.27, I(2)= 0.00, Q= 3.80). Our meta-analysis supports the concept that the use of proximal balloon occlusion compared with filter cerebral protection is associated with a reduction of the amount of CAS-related brain embolization. The data should be confirmed by a randomized clinical trial.

Proximal protection with the Gore PAES can reduce DWI lesion size in high-grade stenosis during carotid stenting

The aim was to determine the incidence of new ischaemic lesions on diffusion-weighted MR imaging (DWI) in a non-randomised cohort of patients after protected and unprotected carotid artery stent placement using the Parodi Anti-Emboli System (PAES). A retrospective review was conducted on 269 patients who received DWI prior to, and 24-72 hours after, stent placement. All patients were enrolled in one centre. Forty patients stented with the PAES device were matched with 229 patients stented without protection (control group). New diffusion restriction on DWI was detected in 25.8% (PAES) versus 32.3% (control group); p=0.64. On average there were 0.7 lesions (PAES) versus 0.8 lesions (control group) per patient. The area of lesions was 1.7 (PAES) versus 5.6 mm2. In a subanalysis of patients (32 PAES, 148 non-protected) with >80% stenosis, the area of restricted diffusion was less when proximal protection was used (p<0.05). The number and area of DWI lesions did not differ on the contralateral, non-stented side. When the PAES system was used, patients were more likely not to have any lesion at all (p=0.028). In high-grade stenosis, the use of the Gore PAES device significantly reduced the area of new DWI lesions and patients were more likely not to have any new DWI lesion at all.

Intentional Hypertension During Dissection of Carotid Arteries in Endarterectomy Prevents Postoperative Development of New Cerebral Ischemic Lesions Caused by Intraoperative Microemboli

Low blood flow velocity in the middle cerebral artery (MCA) correlates with the development of postoperative cerebral ischemic lesions related to generation of microemboli during dissection of carotid arteries in carotid endarterectomy (CEA). The purpose of this prospectively controlled trial was to determine whether increased mean blood flow velocity in the MCA by intentional hypertension during carotid dissection in CEA prevented postoperative development of new cerebral ischemic lesions caused by intraoperative microemboli. Patients with ipsilateral internal carotid artery stenosis (>70%) underwent CEA under transcranial Doppler monitoring of mean blood flow velocity and microembolic signals in the ipsilateral MCA. Attempts were made to keep systolic blood pressure during carotid dissection between -10% and +10% of the preoperative value (controls, n = 65) or above a +10% increase (intentional hypertension group, n = 65). Incidence of new ischemic lesions on postoperative diffusion-weighted magnetic resonance imaging was significantly lower in the intentional hypertension group both for all patients (controls, 15.4%; intentional hypertension group, 3.1%; P = .03) and in a subgroup of 37 patients showing microembolic signals during carotid dissection (controls, 52.6%; intentional hypertension group, 11.1%; P = .013). Logistic regression analysis demonstrated the absence of intentional hyperperfusion (95% confidence interval: 1.77-100.00; P = .012) and high number of microembolic signals (95% confidence interval: 1.00-1.62; P = .05) during carotid dissection were significant independent predictors of the postoperative development of new ischemic lesions on diffusion-weighted magnetic resonance imaging. Increased MCA mean blood flow velocity by intentional hypertension during dissection of the carotid artery in CEA prevents the postoperative development of new cerebral ischemic lesions caused by intraoperative microemboli.

Lesion load in unprotected carotid artery stenting

The purpose of the study was to determine the incidence of new ischemic lesions found on diffusion-weighted MR imaging (DWI) in nonselected patients after unprotected carotid artery stent placement. We retrospectively reviewed a nonrandomized cohort of 197 patients presenting with carotid occlusive disease who underwent unprotected carotid artery stent placement between 2003 and 2006. Mean degree of stenosis was 86.94% +/- 9.72. In all patients, DWI was obtained before and 24 h after stent placement. New lesions were evaluated according to size and location. In 59 of 197 patients (29.9%), new ischemic lesions were found on DWI in the vessel dependent area. In 23 of 197 patients (11.7%), new ischemic lesions were found in the vessel independent area. Combined stroke/death rate was 3.63%. In our series of unprotected carotid angioplasty with stent, we found new DWI lesions in 34% of the patients. Further studies should now show in how far protection devices can reduce these lesions.

New Brain Lesions After Carotid Stenting Versus Carotid Endarterectomy

Against the background of a relatively low rate of clinical events during carotid angioplasty and stenting (CAS) or carotid endarterectomy (CEA), diffusion-weighted imaging (DWI) is increasingly being used to compare the incidence of new ischemic lesions after both procedures. In addition, DWI may also provide a means of defining the role of different CAS techniques on this adverse outcome. Therefore, we performed a PubMed search and systematically analyzed all peer-reviewed studies published between January 1990 and June 2007 reporting on the occurrence of new DWI lesions after CAS or CEA. Summary of Review- In 32 studies comprising 1363 CAS and 754 CEA procedures, the incidence of any new DWI lesion was significantly higher after CAS (37%) than after CEA (10%) (P<0.01). Similar results were obtained in a meta-analysis focusing on those studies directly comparing the incidence of new DWI lesions after either CEA or CAS (OR, 6.1; 95% CI, 4.19 to 8.87; P<0.01). The use of cerebral protection devices (33% vs 45% without; P<0.01) and closed-cell designed stents during CAS (31% vs 51% with open-cell stents; P<0.01), as well as selective versus routine shunt usage during CEA (6% vs 16%; P<0.01) significantly reduced the incidence of new ipsilateral DWI lesions. New DWI lesions occur more frequently after CAS than after CEA. However, technical advances mainly in the field of endovascular therapy potentially reduce the incidence of these adverse ischemic events. In this scenario, DWI appears to be an ideal tool to compare and further improve both techniques.

Cerebral Microembolism During Cardiac Catheterization and Risk of Acute Brain Injury

Cerebral microembolism detected by transcranial Doppler occurs systematically during cardiac catheterization, but its clinical relevance remains unknown. Studies suggest that asymptomatic embolic cerebral infarction detectable by diffusion-weighted (DW) MRI might exist after percutaneous cardiac interventions, especially after retrograde catheterization of the aortic valve in patients with valvular aortic stenosis, with a frequency as high as 22% of cases. We investigated the incidence of new ischemic lesions on serial cerebral DW MRI after cardiac catheterization. This prospective study involved 46 patients with severe aortic valve stenosis. To assess the occurrence of cerebral infarction, all patients underwent cerebral DW MRI and neurological assessment within 24 hours before and 48 hours after cardiac catheterization and retrograde catheterization of the aortic valve. A subgroup was monitored by transcranial power M-mode Doppler during cardiac catheterization to observe cerebral blood flow and track emboli. One patient had a focal diffusion abnormality on DW MRI before cardiac catheterization. After catheterization, we detected only 1 additional acute cerebral diffusion abnormality in a single case (2.2%), although cerebral microemboli were detected in all transcranial Doppler-monitored patients during cardiac catheterization, as expected. All patients remained asymptomatic. Based on these results a mid-point incidence of 5.9% (95% CI, 0.01 to 12.5) for abnormalities on DW MRI in asymptomatic cardiac catheterization patients in our center can be assigned. Unsuspected cerebral infarctions can be detected by DW MRI after cardiac catheterization, but this phenomenon remains unfrequent in our series. Further studies are needed to identify factors explaining the discrepancy between these results and those of previous studies.

Doppler microembolic signals during cardiac surgery: comparison between arterial line and middle cerebral artery

Several studies have demonstrated that the counts of Doppler microembolic signals (MESs) detected during cardiac surgery are related to (1) outcome and length of hospital stay, (2) degree of postoperative neuropsychologic deficit, and (3) incidence of new ischemic lesions on magnetic resonance imaging of the brain. Extracorporeal oxygenation causes varying amounts of air to be diluted in the blood; this air is only partially removed by the arterial filters that are routinely used. We undertook this study to evaluate (1) the percentage of MES reduction caused by the arterial filter and (2) the proportion of MESs actually reaching the brain, by comparing the MES counts detected before the arterial filter, after the arterial filer and in both middle cerebral arteries (MCAs).

Transient ischaemic attacks are associated with increased rates of global cerebral atrophy

Objectives: To determine whether patients presenting with a first transient ischaemic attack (TIA) subsequently show increased rates of brain atrophy compared with age matched controls; and to assess potential risk...