Number needed to treat with intravenous tenecteplase to reduce the need for mechanical thrombectomy in large vessel occlusion acute ischemic stroke patients: A retrospective look at real-world experience data.

OBJECTIVE: We sought to describe short term outcomes in patients with large vessel occlusion acute ischemic stroke (LVOAIS) who were treated with intravenous tenecteplase (TNK) as compared to alteplase (tPA), focusing on reduction in the need for mechanical thrombectomy (MT). BACKGROUND: In LVOAIS, TNK has shown improved reperfusion and outcomes with a similar safety profile to tPA. Ultra-early reperfusion has been described with TNK which would prevent the need for MT. We analyze the magnitude of this effect in a "real-world" setting. DESIGN/METHODS: In this retrospective study, demographic, clinical, and imaging information from patients with LVOAIS treated with intravenous thrombolysis was collected. Data was compared between the group treated with TNK and tPA. RESULTS: One hundred eighty-six patients met the criteria for the study. Of these,144patients received tPA and 42 received TNK. Nine had clinical improvement prior to groin puncture and did not require angiography. When combining the number of patients who had recanalization on angiography before MT and those who had clinical improvement prior to angiography, there were a total of 23 patients. This was noted in 9.7 % of patients who received tPA and 21.4 % of those who received TNK (p = 0.043). For patients treated with TNK we observed a rapid clinical improvement, improved NIHSS, improved functional outcomes and decreased length of stay compared to patients treated with tPA. For patients with spontaneous recanalization either angiographically or with clinical improvement from intravenous thrombolysis, MT may not be required. CONCLUSIONS: Intravenous TNK in patients with LVOAIS decreases the need for MT, and is associated with improved outcomes and reduced length of stay.

Intravenous thrombolysis prior to mechanical thrombectomy does not affect clinical or procedural outcomes in patients with large vessel occlusion acute ischemic stroke.

Mechanical thrombectomy (MT) has revolutionized the care of large vessel occlusion acute ischemic strokes (LVOAIS). However, the benefit of intravenous thrombolysis prior to MT remains unproven. Two recent trials showed equivocal results regarding the benefits of pre-MT intravenous thrombolysis in predominantly Asian populations. We evaluated clinical outcomes and procedural metrics for patients with LVOAIS who were treated with MT alone compared to those who were treated with both intravenous tPA and MT. In a retrospective study, LVOAIS patients treated with MT, with or without preceding intravenous thrombolysis, between January of 2017 and December of 2019 were identified. Patients were treated according to contemporary guidelines. Baseline demographic and clinical characteristics, procedural metrics, and clinical outcomes were collected. Among LVOAIS patients, those treated with intravenous thrombolysis and MT did not differ from those with MT alone on clinical outcomes at three months. Further, the two groups did not differ on thrombectomy procedure times, recanalization rates, and symptomatic intracranial hemorrhage rates. In our patients with LVOAIS, intravenous thrombolysis combined with MT offered no advantage compared to MT alone in clinical outcomes or recanalization rates. Our results are consistent with earlier studies in other populations. In addition, our results suggest that IV tPA does not impact the ease of clot removal by MT. Further studies will evaluate how newly available thrombolytic agents may benefit patients eligible for MT.

Cost Analysis of the Addition of Hyperacute Magnetic Resonance Imaging for Selection of Patients for Endovascular Stroke Therapy.

BACKGROUND AND PURPOSE: Patient selection is important to determine the best candidates for endovascular stroke therapy. In application of a hyperacute magnetic resonance imaging (MRI) protocol for patient selection, we have shown decreased utilization with improved outcomes. A cost analysis comparing the pre- and post-MRI protocol time periods was performed to determine if the previous findings translated into cost opportunities. MATERIALS AND METHODS: We retrospectively identified individuals considered for endovascular stroke therapy from January 2008 to August 2012 who were ≤8 h from stroke symptoms onset. Patients prior to April 30, 2010 were selected based on results of the computed tomography/computed tomography angiography alone (pre-hyperacute), whereas patients after April 30, 2010 were selected based on results of MRI (post-hyperacute MRI). Demographic, outcome, and financial information was collected. Log-transformed average daily direct costs were regressed on time period. The regression model included demographic and clinical covariates as potential confounders. Multiple imputation was used to account for missing data. RESULTS: We identified 267 patients in our database (88 patients in pre-hyperacute MRI period, 179 in hyperacute MRI protocol period). Patient length of stay was not significantly different in the hyperacute MRI protocol period as compared to the pre-hyperacute MRI period (10.6 vs. 9.9 days, p < 0.42). The median of average daily direct costs was reduced by 24.5% (95% confidence interval 14.1-33.7%, p < 0.001). CONCLUSIONS: Use of the hyperacute MRI protocol translated into reduced costs, in addition to reduced utilization and better outcomes. MRI selection of patients is an effective strategy, both for patients and hospital systems.

Endovascular Embolization of Intracranial Infectious Aneurysms in Patients Undergoing Open Heart Surgery Using n-Butyl Cyanoacrylate.

INTRODUCTION: Mycotic aneurysms are a serious complication of infective endocarditis with increased risk of intracranial hemorrhage. Patients undergoing open heart surgery for valve repair or replacement are exposed to anticoagulants, increasing the risk of aneurysm bleeding. These patients may require endovascular or surgical aneurysm treatment prior to heart surgery, but data on this approach are scarce. METHODS: Retrospective review of consecutive patients with infectious endocarditis and mycotic aneurysms treated endovascularly with Trufill n-butyl cyanoacrylate (n-BCA) at the Cleveland Clinic between January 2013 and December 2015. RESULTS: Nine patients underwent endovascular treatment of mycotic aneurysms with n-BCA (mean age of 39 years). On imaging, 4 patients had intracerebral hemorrhage, 2 had multiple embolic infarcts, and the rest had no imaging findings. Twelve mycotic aneurysms were detected (3 patients with 2 aneurysms). Seven aneurysms were in the M4 middle cerebral artery segment, 4 in the posterior cerebral artery distribution, and 1 in the callosomarginal branch. n-BCA was diluted in ethiodized oil (1:1 to 1:2). Embolization was achieved in a single rapid injection with immediate microcatheter removal. Complete aneurysm exclusion was achieved in all cases without complications. All patients underwent open heart surgery and endovascular embolization within a short interval, 2 with both procedures on the same day. There were no new hemorrhages after aneurysm embolization. CONCLUSIONS: Endovascular embolization of infectious intracranial aneurysms with liquid embolics can be performed successfully in critically ill patients requiring immediate open heart surgery and anticoagulation. Early embolization prior to and within a short interval from open heart surgery is feasible.

ASPECTS discrepancies between CT and MR imaging: analysis and implications for triage protocols in acute ischemic stroke.

BACKGROUND: Optimal imaging triage for intervention for large vessel occlusions remains unclear. MR-based imaging provides ischemic core volumes at the cost of increased imaging time. CT Alberta Stroke Program Early CT Score (ASPECTS) estimates are faster, but may be less sensitive. OBJECTIVE: To assesses the rate at which MRI changed management in comparison with CT imaging alone. METHODS: Retrospective analysis of patients with acute ischemic stroke undergoing imaging triage for endovascular therapy was performed between 2008 and 2013. Univariate and multivariate analyses were performed. Multivariate logistic regression was used to evaluate the effect of time on disagreement in MRI and CT ASPECTS scores. RESULTS: A total of 241 patients underwent both diffusion-weighted imaging (DWI) and CT. Six patients with DWI ASPECTS ≥6 and CT ASPECTS <6 were omitted, leaving 235 patients. For 47 patients, disagreement between the two modalities resulted in different treatment recommendations. The estimated probability of disagreement was 20.0% (95% CI 15.4% to 25.6%). In a multivariate logistic regression, CT ASPECTS >7 (p=0.004) and admission National Institutes of Health Stroke Scale (NIHSS) score <16 (p=0.008) were simultaneously significant predictors of agreement in ASPECTS. The time between modalities was a marginally significant predictor (p=0.080). CONCLUSIONS: The study suggests that patients with NIHSS scores at admission of <16 and patients with CT ASPECTS >7 have a higher likelihood of agreement between CT and DWI based on an ASPECTS cut-off value of 6. Additional MRI for triage in patients with NIHSS at admission of >16, and ASPECTS of 6 or 7 may be more likely to change management. Unsurprisingly, patients with low CT ASPECTS had good correlation with MRI ASPECTS.

Treatment of patients with mild acute ischemic stroke and associated large vessel occlusion.

Several recent studies have shown that patients presenting with mild acute ischemic stroke (mAIS) symptoms may have an unfavorable natural history. The presence of associated large vessel occlusion (LVO) may lead to even worse outcomes, but most mAIS patients are still excluded from acute stroke treatment (AST). A retrospective review of patients with acute ischemic stroke presenting to our institution between 2010 and 2014 was carried out. Inclusion criteria were mAIS (initial National Institutes of Health Stroke Scale [NIHSS] ⩽7) due to LVO, presenting within 6hours from onset. Demographics, treatments and short-term outcomes were analyzed. Favorable 30day outcome was defined as modified Rankin Scale (mRS) ⩽2. Out of 2636 patients, 62 patients (median age 63years, 33 (53.2%) males) met inclusion criteria. The anterior circulation was involved in 74.1%. Median admission NIHSS and pre-admission mRS were 4 and 0, respectively. Twenty-three patients (71.8%) received AST (intravenous tissue plasminogen activator: 14, intra-arterial therapy: 4, both: 5). Favorable outcomes were 4.5 times higher in treated (78.3%) versus untreated (53.8%) patients (odds ratio 4.5, 95% confidence interval 1.26-19.2; p=0.028). None of the treated patients had symptomatic intracranial hemorrhage. We demonstrate that a significant proportion of untreated mAIS patients with LVO have an unfavorable natural history. Our results suggest better outcomes in patients who receive early therapy rather than conservative management. The detection of LVO, even with mild clinical symptoms, may prompt rapid treatment considerations.

High-resolution MRI vessel wall imaging in varicella zoster virus vasculopathy.

Contrast-enhanced vessel wall imaging high-resolution MRI (HRMR) has revealed vessel wall thickening and enhancement in multiple intracranial vasculopathies, including varicella zoster virus (VZV) vasculopathy. We retrospectively reviewed a database of patients with virologically-verified VZV vasculopathy, who underwent initial and follow-up HRMR between April 2011 and May 2014. Six patients were identified. Baseline demographic and clinical characteristics were collected, including stroke risk factors, history of VZV-related disorders, neurological presentation, course and antiviral treatment. Initial HRMR in patients with VZV vasculopathy demonstrated various patterns of stenosis, vessel wall thickening and enhancement, predominantly in terminal internal carotid artery segments and the M1 segment of the middle cerebral arteries. Follow-up HRMR showed improvement of stenosis, with reduced vessel wall thickening and enhancement at multiple times after treatment. HRMR has the potential to assist in diagnosis and treatment of VZV vasculopathy.

Diffusion-weighted imaging volume as the best predictor of the diffusion-perfusion mismatch in acute stroke patients within 8 hours of onset.

BACKGROUND: Diagnostic accuracies of standard NCCT, CTA, CTA-SI, FLAIR, and DWI to detect the diffusion-perfusion mismatch (DPM) were compared. METHODS: Stroke patients considered for endovascular therapy within 8 hours of onset were enrolled. DPM was defined as at least 160% mismatch between DWI and PWI volume. RESULTS: DPM was seen in 35 (71%) of 49 patients. ASPECTS on NCCT, CTA-SI, and DWI was 9 (8-9), 8 (6-9), and 7 (5-9) in mismatch group, and 6 (4-9), 6 (2-7), 5 (2-6) in nonmismatch group, respectively (P = .027, .006, and .001). Ischemic volume on CTA-SI and DWI was 4.6 (.2-13.0) cm(3) and 21.5 (9.7-44.0) cm(3) in mismatch group, and 61.5 (6.6-101.1) cm(3) and 94.9 (45.7-139.8) cm(3) in nonmismatch group (P = .003 and <.001). Significant collateralization on CTA-SI and FLAIR was seen in 80% and 88% in mismatch group, and 42% and 58% in nonmismatch group (P = .026 and .039). Odds ratios (95% CI) of DWI volume of ≤ 70 cm(3) to predict the mismatch was 30.17 (2.06-442.41) after adjusting for ASPECTSs on NCCT, CTA-SI, and DWI, 44.90 (2.75-732.73) for ischemic volume on CTA-SI, and 42.80 (3.05-601.41) for significant collateralization on CTA-SI and FLAIR (P = .013, .008, and .005). CONCLUSIONS: DWI volume was the best predictor of DPM.

The location of pretreatment hyperdense middle cerebral artery sign predicts the outcome of intraarterial thrombectomy for acute stroke.

BACKGROUND AND PURPOSE: Intraarterial (IA) mechanical thrombectomy has an excellent recanalization rate but does not always correlate with good clinical outcomes. We aimed to investigate whether hyperdense middle cerebral artery sign (HMCAS) on preintervention nonenhanced CT (NECT) predicts IA therapy outcome for acute stroke. METHODS: Data were abstracted from our Hyperacute Ischemic Stroke database. Patients with occlusion in ICA, MCA, or MCA M2 branches who underwent IA therapy were included. RESULTS: Among 126 patients who underwent IA treatment, 64 (51%) had hyperdense M1 MCA sign (M1 HMCAS), 11 (9%) had hyperdense M2, and 51 (40%) had No HMCAS (NHMCAS).M1 HMCAS and NHMCAS group has comparable baseline stroke severity and infarct volume (P > .05); and the differences of favorable outcome (modified Rankin Score 0-2) at 30 days were not significant (21% vs. 30%, P = .259). For those with HMCAS, favorable 30-day outcome was most frequent in Distal HMCAS (39%), followed by hyperdense M2 (27%), HMCAS proximal (11%), and HMCAS full length (0%). CONCLUSIONS: For acute ischemic stroke due to large vessel occlusion, the lack of HMCAS on NECT does not predict favorable outcome after IA therapy. Among those with HMCAS, proximal and longer HMCAS predicts unfavorable outcome.

Collateral flow and brain changes on computed tomography angiography predict infarct volume on early diffusion-weighted imaging.

BACKGROUND: We investigated whether a computed tomography (CT)-based score could predict a large infarct (≥ 80 mL) on early diffusion-weighted magnetic resonance imaging (DWI). METHODS: Acute stroke patients considered for endovascular therapy within 8 hours of the onset of symptoms were included. The Alberta Stroke Program Early Computed Tomography Score (ASPECTS) was determined on noncontrast CT and computed tomography angiography source images (CTA-SI). Limited collateral flow was defined as less than 50% collateral filling on CTA-SI. RESULTS: Fifty-six patients were analyzed. National Institutes of Health Stroke Scale score was 20 (15-24) in the large infarct group and 16 (11-20) in the small infarct group (P = .049). ASPECTS on noncontrast CT and CTA-SI was 5 (3-8) and 3 (2-6) in the large infarct group and 9 (8-10) and 8 (7-9) in the small infarct group (both P < .001), respectively. Limited collateral flow was frequent in the large infarct group than in the small infarct group (92% vs. 11%, P < .001). Multivariate analysis found that CTA-SI ASPECTS less than or equal to 5 (odds ratio [OR], 40.55; 95% confidence interval [CI], 1.10-1493.44; P = .044) and limited collateral flow (OR, 114.64; 95% CI, 1.93-6812.79; P = .023) were associated with a large infarct. Absence of ASPECTS less than or equal to 5 and limited collateral flow on CTA-SI predicted absence of a large infarct with a sensitivity of .89, specificity of 1.00, positive predictive value of 1.00, and negative predictive value of .71. CONCLUSIONS: Assessment of ASPECTS and collateral flow on CTA-SI may be able to exclude a patient with large infarct on early DWI.

Addition of hyperacute MRI AIDS in patient selection, decreasing the use of endovascular stroke therapy.

BACKGROUND AND PURPOSE: The failure of recent trials to show the effectiveness of acute endovascular stroke therapy (EST) may be because of inadequate patient selection. We implemented a protocol to perform pretreatment MRI on patients with large-vessel occlusion eligible for EST to aid in patient selection. METHODS: We retrospectively identified patients with large-vessel occlusion considered for EST from January 2008 to August 2012. Patients before April 30, 2010, were selected based on computed tomography/computed tomography angiography (prehyperacute protocol), whereas patients on or after April 30, 2010, were selected based on computed tomography/computed tomography angiography and MRI (hyperacute MRI protocol). Demographic, clinical features, and outcomes were collected. Univariate and multivariate analyses were performed. RESULTS: We identified 267 patients: 88 patients in prehyperacute MRI period and 179 in hyperacute MRI period. Fewer patients evaluated in the hyperacute MRI period received EST (85 of 88, 96.6% versus 92 of 179, 51.7%; P<0.05). The hyperacute-MRI group had a more favorable outcome of a modified Rankin scale 0 to 2 at 30 days as a group (6 of 66, 9.1% versus 33 of 140, 23.6%; P=0.01), and when taken for EST (6 of 63, 9.5% versus 17 of 71, 23.9%; P=0.03). On adjusted multivariate analysis, the EST in the hyperacute MRI period was associated with a more favorable outcome (odds ratio, 3.4; 95% confidence interval, 1.1-10.6; P=0.03) and reduced mortality rate (odds ratio, 0.16; 95% confidence interval, 0.03-0.37; P<0.001). CONCLUSIONS: Implementation of hyperacute MRI protocol decreases the number of endovascular stroke interventions by half. Further investigation of MRI use for patient selection is warranted.

Last resort: case of clot translocation in intra-arterial stroke therapy.

A patient was taken for emergent intra-arterial stroke therapy for an acute left middle cerebral artery stroke syndrome, with CT angiography showing a left internal carotid artery (ICA) occlusion. Through a 6 F Neuron MAX sheath, a 5 Max ACE Penumbra aspiration catheter was advanced to the thrombus and direct suction was performed through the ACE catheter and Neuron MAX sheath. Upon pull back, the thrombus became wedged in the Neuron MAX sheath and despite several attempts to aspirate the thrombus, no clot could be obtained. The Neuron MAX sheath was withdrawn to the left common carotid artery, and gently advanced to the origin of the external carotid artery (ECA). A glide wire was advanced and the thrombus dislodged into the ECA. Another pass with the 5 Max ACE was used to remove a remaining thrombus in the left ICA terminus, resulting in Thrombolysis in Cerebral Infarction (TICI) 3 flow. With improved devices for embolectomy, large and rigid emboli that exceed the inner diameter of large guide sheaths and balloon guide catheters can become lodged, and cannot be withdrawn through a catheter. While uncommon, strategies to overcome this are important to keep in mind during acute stroke intervention.

Last resort: case of clot translocation in intra-arterial stroke therapy.

A patient was taken for emergent intra-arterial stroke therapy for an acute left middle cerebral artery stroke syndrome, with CT angiography showing a left internal carotid artery (ICA) occlusion. Through a 6 F Neuron MAX sheath, a 5 Max ACE Penumbra aspiration catheter was advanced to the thrombus and direct suction was performed through the ACE catheter and Neuron MAX sheath. Upon pull back, the thrombus became wedged in the Neuron MAX sheath and despite several attempts to aspirate the thrombus, no clot could be obtained. The Neuron MAX sheath was withdrawn to the left common carotid artery, and gently advanced to the origin of the external carotid artery (ECA). A glide wire was advanced and the thrombus dislodged into the ECA. Another pass with the 5 Max ACE was used to remove a remaining thrombus in the left ICA terminus, resulting in Thrombolysis in Cerebral Infarction (TICI) 3 flow. With improved devices for embolectomy, large and rigid emboli that exceed the inner diameter of large guide sheaths and balloon guide catheters can become lodged, and cannot be withdrawn through a catheter. While uncommon, strategies to overcome this are important to keep in mind during acute stroke intervention.

Isolated bilateral middle cerebellar peduncle infarcts.

Our objective is to report an interesting case of a patient with known severe vertebrobasilar disease who presented with isolated bilateral middle cerebellar peduncle (MCP) infarction. Isolated infarction of the MCP is uncommon, occurring in roughly 0.12% of acute strokes. Isolated bilateral MCP infarction is extremely rare and has been described in only a few cases in the literature. The MCP is a watershed zone between the anterior inferior cerebellar artery and the superior cerebellar artery and its occurrence suggests hypoperfusion.

Update on pharmacology of antiplatelets, anticoagulants, and thrombolytics.

Understanding of the pharmacology of thrombolytics, anticoagulants, and antiplatelets is critical to performing safe and effective endovascular therapy for acute ischemic therapy. This is a basic review of the clinical pharmacologic data on the anticoagulants, antiplatelets, and fibrinolytic agents most commonly used in the treatment of stroke and in the neurointerventional suite.

Multicenter analysis of stenting in symptomatic intracranial atherosclerosis.

BACKGROUND: Stenting for symptomatic intracranial atherosclerotic disease is a therapeutic option in patients in whom medical therapy fails. OBJECTIVE: To determine the periprocedural complication rates and mid-term restenosis rates in patients treated with balloon-expandable stents (BESs) compared with self-expanding stents (SESs). METHODS: A retrospective review of consecutive patients treated with intracranial stents at 5 institutions was performed. Predictors of 30-day stroke and death as well as mid-term restenosis rates were analyzed. RESULTS: A total of 670 lesions were treated in 637 patients with a mean age of 57 ± 13 years. A total of 454 lesions (68%) were treated with BESs and 216 lesions (32%) with SESs. The overall 30-day periprocedural complication rate was 6.1%, without any difference noted between the 2 groups. Patients treated within 24 hours of the index event were significantly more likely to have experienced a periprocedural complication (odds ratio [OR], 4.0; 95% confidence interval [CI]: 1.7-6.7; P < .007), whereas focal lesions were less likely to have a complication (OR, 0.31; 95% CI: 0.13-0.72; P < .001). Midterm restenosis was less likely in patients with a lower percentage of posttreatment stenosis (OR, 0.97; 95% CI: 0.95-0.99; P < .006), which was more common in BES-treated patients and focal concentric lesions (OR, 0.33; 95% CI: 0.23-0.55; P < .0001). CONCLUSION: BESs have periprocedural complication rates similar to those of SESs. Less posttreatment stenosis was associated with lower rates of mid-term restenosis. Future randomized trials comparing BESs and SESs may help to identify the stent type that is safest and most durable.

Intra-arterial thrombolysis or stent placement during endovascular treatment for acute ischemic stroke leads to the highest recanalization rate: results of a multicenter retrospective study.

BACKGROUND: Reperfusion therapy for acute ischemic stroke (AIS) is rapidly evolving, with the development of multiple endovascular modalities that can be used alone or in combination. OBJECTIVE: To determine which pharmacologic or mechanical modality may be associated with increased rates of recanalization. METHODS: A cohort of 1122 patients with AIS involving the anterior circulation treated at 13 stroke centers underwent intra-arterial (IA) therapy within 8 hours of symptom onset. Demographic information, admission National Institutes of Health Stroke Scale (NIHSS), mechanical and pharmacologic treatments used, recanalization grade, and hemorrhagic complications were recorded. RESULTS: The mean age was 67 ± 16 years and the median NIHSS was 17. The sites of arterial occlusion before treatment were M1 middle cerebral artery (MCA) in 561 (50%) patients, carotid terminus in 214 (19%) patients, M2 MCA in 171 (15%) patients, tandem occlusions in 141 (13%) patients, and isolated extracranial internal carotid artery occlusion in 35 (3%) patients. Therapeutic interventions included multimodal therapy in 584 (52%) patients, pharmacologic therapy only in 264 (24%) patients, and mechanical therapy only in 274 (24%) patients. Patients treated with multimodal therapy had a significantly higher Thrombolysis in Myocardial Infarction 2 or 3 recanalization rate (435 patients [74%]) compared with pharmacologic therapy only (160 patients, [61%]) or mechanical only therapy (173 patients [63%]), P<.001. In binary logistic regression modeling, independent predictors of Thrombolysis in Myocardial Infarction 2 or 3 recanalization were use of IA thrombolytic OR 1.58 (1.21-2.08), P<.001 and stent deployment 1.91 (1.23-2.96), P<.001. CONCLUSION: Multimodal therapy has significantly higher recanalization rates compared with pharmacologic or mechanical therapy. Among the individual treatment modalities, stent deployment or IA thrombolytics increase the chance of recanalization.

Predictors of biochemical aspirin and clopidogrel resistance in patients with ischemic stroke.

Variable platelet response to aspirin and clopidogrel is a well-established phenomenon in patients with coronary artery disease. We sought to determine the predictors of an impaired biochemical response to aspirin and clopidogrel in patients with ischemic stroke. Patients with established cerebrovascular disease who underwent an aspirin/clopidogrel response panel (ie, light transmittance aggregometry) between June 2003 and March 2007 were identified through an electronic database. The medical records of these patients were retrospectively reviewed, and demographic characteristics, medical history, and laboratory results were recorded. Univariate and multivariate logistic regression analyses were performed to assess for factors associated with antiplatelet resistance. Of the 465 patients included in this study, 120 (28%) were biochemical aspirin nonresponders and 83 (28%) were biochemical clopidogrel nonresponders. Of the 270 patients on dual antiplatelet therapy, 25 (9.3%) were dual biochemical nonresponders. In binary logistic regression modeling, patients with congestive heart failure (odds ratio [OR] = 4.54; 95% confidence interval [CI] = 1.33-15.5; P = .02) and those with higher hemoglobin A1c values (OR = 1.41; 95% CI = 1.12-1.79; P = .004) had a significantly greater likelihood of having a biochemical nonresponse to aspirin therapy. African-American patients (OR = 2.19; 95% CI = 1.23-3.91; P < .007) were significantly more likely to be nonresponders to clopidogrel. This preliminary study shows that aspirin and clopidogrel biochemical nonresponse frequently occurs in ischemic stroke patients. In addition, some associated variables may affect the biochemical response to antiplatelet therapy. Further study is needed to explore whether this nonresponse has an impact on clinical outcomes.

Intracranial atherosclerosis as a risk factor for ischemic stroke during open heart surgery.

BACKGROUND: Embolic stroke is a feared complication after open heart surgery. Many patients undergo testing of the carotid arteries before surgery, but intracranial atherosclerosis is not commonly assessed as a mechanism. METHODS: We reviewed a prospectively maintained database of all open heart surgeries at our institution from 2005 to 2007 for patients who developed a periprocedural ischemic stroke. These patients were assessed for the mechanism of stroke through radiographic imaging of the intracranial circulation to determine the frequency of intracranial atherosclerosis as a mechanism for perioperative stroke. RESULTS: A total of 10,367 patients underwent open heart surgery from 2005 to 2007 and 180 (1.74%) patients were noted to have an ischemic stroke. Of the 180 patients, 98 (55%) underwent intracranial imaging and 29 (30%) were noted to have narrowing of an intracranial vessel. Seventeen (17.4%) patients were found to have infarct ipsilateral to the stenosis, but 8 (8.1%) of these patients were also noted to have infarcts in other vascular territories. Thus, 9 (9.1%) patients were thought to have a stroke solely related to the intracranial stenosis. CONCLUSIONS: Intracranial atherosclerosis may be an underreported mechanism for perioperative stroke after open heart surgery. Further study is required to better understand the prevalence of the disease in this population and subsequent risk of stroke.

Initial experience with angioplasty of symptomatic M2 MCA atheromatous lesions.

BACKGROUND AND PURPOSE: Symptomatic intracranial atherosclerosis has been associated with a high rate of recurrent stroke. The safety of treatment of more distal atheromatous lesions with angioplasty has not been systematically reported. METHODS: We retrospectively reviewed our institutional database for all patients treated with intracranial angioplasty and stenting from January 2008 to July 2009. A total of 108 patients were treated and five patients were treated with angioplasty for a symptomatic M2 middle cerebral artery stenosis with fluctuating neurological examinations. We report our experience with these patients. RESULTS: All five patients underwent technically successful treatment with a reduction of the stenosis to <50%. There were no periprocedural complications and all patients had cessation of their clinical fluctuations. Two patients were found to have symptomatic restenosis with one patient suffering a disabling stroke at 5 months and the second patient a transient ischemic attack at 4 months who was subsequently successfully re-treated with angioplasty and stent placement. CONCLUSIONS: Angioplasty of M2 MCA lesions is technically feasible in our cohort of neurologically unstable patients, but the durability of this treatment will require more extensive study.