Lucas Elijovich

Intermittent Atrial Fibrillation May Account for a Large Proportion of Otherwise Cryptogenic Stroke: A Study of 30-Day Cardiac Event Monitors

INTRODUCTION Despite extensive inpatient workup including telemetry monitoring, a significant proportion of stroke is classified as cryptogenic at hospital discharge. It is possible that a significant proportion of cryptogenic stroke is a result of intermittent atrial fibrillation (AF). Thirty-day cardiac event monitors (30-DEM) may increase the rate of AF detection compared with standard investigations that include a combination of electrocardiography, cardiac telemetry, and short-term Holter monitoring. METHODS Charts were reviewed of patients who were admitted to a university stroke center or who were evaluated in the outpatient clinic during a 9-month period to determine whether the cause of stroke was cryptogenic. As a matter of protocol, such patients typically underwent 30-DEM and the results of such monitoring were documented along with the duration of inpatient cardiac monitoring if relevant. RESULTS In all, 218 patients with a diagnosis of ischemic stroke or transient ischemic attack were identified. Of the strokes, 36 (16.5%) were classified as cryptogenic. Twenty patients with cryptogenic stroke or transient ischemic attack were evaluated with 30-DEM. Four (20%) were found to have AF, and all 4 patients were treated with warfarin. CONCLUSION The 30-DEM changed the medical treatment of 20% of patients with otherwise cryptogenic stroke because of the detection of intermittent AF despite no detection of AF on electrocardiography and inpatient telemetry monitoring in the majority of patients. Further prospective studies of extended cardiac event monitors in the setting of cryptogenic stroke are warranted.

Predictors and Outcomes of Intraprocedural Rupture in Patients Treated for Ruptured Intracranial Aneurysms. The CARAT Study

Background and Purpose— Intraprocedural rupture (IPR) is a well known complication of intracranial aneurysm treatment. Risks and predictors of IPR and its impact on outcome have not been clearly established. Methods— Potential predictors of IPR were evaluated in patients treated in the Cerebral Aneurysm Rerupture After Treatment (CARAT) study using multivariate logistic regression with stepwise elimination stratified by treatment modality. Periprocedural death or disability was defined as death or a change of ≥2 points on the Modified Rankin Scale at discharge compared to before treatment. Results— IPR occurred in 14.6% of 1010 patients (299 coiled, 711 clipped): 19% with clipping and 5% with coiling (P<0.001). Among those clipped, 31% with IPR had periprocedural death or disability compared to 18% without IPR (P=0.001); among those coiled, 63% with IPR had periprocedural death or disability compared to 15% without IPR (P<0.001). Overall, coronary artery disease and initial lower Hunt and Hess Grade were independent predictors of IPR. For those undergoing coiling, independent predictors of IPR were Asian race, black race, COPD, and lower initial Hunt and Hess Grade. Among those undergoing clipping, hyperlipidemia and lower initial Hunt and Hess Grade were both independent predictors of IPR. Conclusions— IPR was common in patients undergoing treatment of ruptured aneurysms, particularly with surgical clipping. The frequency of IPR with new disability was similar in the surgical and endovascular treatment groups. Coronary artery disease, hyperlipidemia, race, COPD, and lower Hunt and Hess Grade were associated with greater risk of IPR, which may reflect differences in vessel fragility but requires further confirmation.

Distal aspiration with retrievable stent assisted thrombectomy for the treatment of acute ischemic stroke

Objective Flexible large lumen aspiration catheters and stent retrievers have recently become available in the USA for the revascularization of large vessel occlusions presenting within the context of acute ischemic stroke (AIS). We describe a multicenter experience using a combined aspiration and stent retrieval technique for thrombectomy. Design A retrospective analysis to identify patients receiving combined manual aspiration and stent retrieval for treatment of AIS between August 2012 and April 2013 at six high volume stroke centers was conducted. Outcome variables, including recanalization rate, post-treatment National Institutes of Health Stroke Scale (NIHSS) score, symptomatic intracranial hemorrhage, discharge 90 day modified Rankin Scale (mRS) score, and mortality were evaluated. Results 105 patients were found that met the inclusion criteria for this retrospective study. Successful recanalization (Thrombolysis in Cerebral Infarction score 2B) was achieved in 92 (88%) of these patients. 44% of patients had favorable (mRS score 0–2) outcomes at 90 days. There were five (4.8%) symptomatic intracerebral hemorrhages and three procedure related deaths (2.9%). Conclusions Mechanical thrombectomy utilizing combined manual aspiration with a stent retriever is an effective and safe strategy for endovascular recanalization of large vessel occlusions presenting within the context of AIS.

Pilot Randomized Trial of Outpatient Cardiac Monitoring After Cryptogenic Stroke

Background and Purpose— Observational studies indicate that outpatient cardiac monitoring detects previously undiagnosed atrial fibrillation (AF) in 5% to 20% of patients with recent stroke. However, it remains unknown whether the yield of monitoring exceeds that of routine clinical follow-up. Methods— In a pilot trial, we randomly assigned 40 patients with cryptogenic ischemic stroke or high-risk transient ischemic attack to wear a Cardionet mobile cardiac outpatient telemetry monitor for 21 days or to receive routine follow-up alone. After thorough investigation, we excluded patients with documented AF or other apparent stroke pathogenesis. We contacted patients and their physicians at 3 months and at 1 year to ascertain any diagnoses of AF or recurrent stroke or transient ischemic attack. Results— The baseline characteristics of our cohort broadly matched those of previous observational studies of monitoring after stroke. In the monitoring group, patients wore monitors for 64% of the assigned days, and 25% of patients were not compliant at all with monitoring. No patient in either study arm received a diagnosis of AF. Cardiac monitoring revealed AF in zero patients (0%; 95% confidence interval, 0%–17%), brief episodes of atrial tachycardia in 2 patients (10%; 95% confidence interval, 1%–32%), and nonsustained ventricular tachycardia in 2 patients (10%; 95% confidence interval, 1%–32%). Conclusions— In the first reported randomized trial of cardiac monitoring after cryptogenic stroke, the rate of AF detection was lower than expected, incidental arrhythmias were frequent, and compliance with monitoring was suboptimal. Our findings highlight the challenges of prospectively identifying stroke patients at risk for harboring paroxysmal AF and ensuring adequate compliance with cardiac monitoring. Clinical Trial Registration— URL: http://clinicaltrials.gov. Unique Identifier: NCT00715533

Endovascular therapy for acute ischemic stroke with occlusion of the middle cerebral artery M2 segment

Importance Randomized clinical trials have shown the superiority of endovascular therapy (EVT) compared with best medical management for acute ischemic strokes with large vessel occlusion (LVO) in the anterior circulation. However, of 1287 patients enrolled in 5 trials, 94 with isolated second (M2) segment occlusions were randomized and 51 of these received EVT, thereby limiting evidence for treating isolated M2 segment occlusions as reflected in American Heart Association guidelines. Objective To evaluate EVT safety and effectiveness in M2 occlusions in a cohort of patients with acute ischemic stroke. Design, Setting, and Participants This multicenter retrospective cohort study pooled patients with acute ischemic strokes and LVO isolated to M2 segments from 10 US centers. Patients with acute ischemic strokes and LVO in M2 segments presenting within 8 hours from their last known normal clinical status (LKN) from January 1, 2012, to April 30, 2015, were divided based on their treatment into EVT and medical management groups. Logistic regression was used to compare the 2 groups. Univariate and multivariate analyses evaluated associations with good outcome in the EVT group. Main Outcomes and Measures The primary outcome was the 90-day modified Rankin Scale score (range, 0-6; scores of 0-2 indicate a good outcome); the secondary outcome was symptomatic intracerebral hemorrhage. Results A total of 522 patients (256 men [49%]; 266 women [51%]; mean [SD] age, 68 [14.3] years) were identified, of whom 288 received EVT and 234 received best medical management. Patients in the medical management group were older (median [interquartile range] age, 73 [60-81] vs 68 [56-78] years) and had higher rates of intravenous tissue plasminogen activator treatment (174 [74.4%] vs 172 [59.7%]); otherwise the 2 groups were balanced. The rate of good outcomes was higher for EVT (181 [62.8%]) than for medical management (83 [35.4%]). The EVT group had 3 times the odds of a good outcome as the medical management group (odds ratio [OR], 3.1; 95% CI, 2.1-4.4; P < .001) even after adjustment for age, National Institute of Health Stroke Scale (NIHSS) score, Alberta Stroke Program Early Computed Tomographic Score (ASPECTS), intravenous tissue plasminogen activator treatment, and time from LKN to arrival in the emergency department (OR, 3.2; 95% CI, 2-5.2; P < .001). No statistical difference in symptomatic intracerebral hemorrhage was found (5.6% vs 2.1% for the EVT group vs the medical management group; P = .10). The treatment effect did not change after adjusting for center (OR, 3.3; 95% CI, 1.9-5.8; P < .001). Age, NIHSS score, ASPECTS, time from LKN to reperfusion, and successful reperfusion score of at least 2b (range, 0 [no perfusion] to 3 [full perfusion with filling of all distal branches]) were independently associated with good outcome of EVT. A linear association was found between good outcome and time from LKN to reperfusion. Conclusions and Relevance Although a randomized clinical trial is needed to confirm these findings, available data suggest that EVT is reasonable, safe, and effective for LVO of the M2 segment relative to best medical management.

Clinical and Procedural Predictors of Outcomes From the Endovascular Treatment of Posterior Circulation Strokes

Background and Purpose— Patients with posterior circulation strokes have been excluded from recent randomized endovascular stroke trials. We reviewed the recent multicenter experience with endovascular treatment of posterior circulation strokes to identify the clinical, radiographic, and procedural predictors of successful recanalization and good neurological outcomes. Methods— We performed a multicenter retrospective analysis of consecutive patients with posterior circulation strokes, who underwent thrombectomy with stent retrievers or primary aspiration thrombectomy (including A Direct Aspiration First Pass Technique [ADAPT] approach). We correlated clinical and radiographic outcomes with demographic, clinical, and technical characteristics. Results— A total of 100 patients were included in the final analysis (mean age, 63.5±14.2 years; mean admission National Institutes of Health Stroke Scale score, 19.2±8.2). Favorable clinical outcome at 3 months (modified Rankin Scale score ⩽2) was achieved in 35% of patients. Successful recanalization and shorter time from stroke onset to the start of the procedure were significant predictors of favorable clinical outcome at 90 days. Stent retriever and aspiration thrombectomy as primary treatment approaches showed comparable procedural and clinical outcomes. None of the baseline advanced imaging modalities (magnetic resonance imaging, computed tomographic perfusion, or computed tomography angiography assessment of collaterals) showed superiority in selecting patients for thrombectomy. Conclusions— Time to the start of the procedure is an important predictor of clinical success after thrombectomy in patients with posterior circulation strokes. Both stent retriever and aspiration thrombectomy as primary treatment approaches are effective in achieving successful recanalization.

Fibrinolysis for Intraventricular Hemorrhage An Updated Meta-Analysis and Systematic Review of the Literature

Background and Purpose— Intraventricular hemorrhage is associated with high mortality and poor functional outcome. The use of intraventricular fibrinolytic (IVF) therapy as an intervention in intraventricular hemorrhage is an evolving therapy with conflicting reports in the literature. The goal of this study is to investigate the impact of IVF on mortality, functional outcome, ventriculitis, shunt dependence, and rehemorrhage. Methods— During March and April 2014, a systematic literature search was performed identifying 1359 articles. Of these, 24 met inclusion criteria. A random effects meta-analysis was performed using both pooled and subset analysis based on study type. Results— Our meta-analysis demonstrated that IVF reduced mortality in intraventricular hemorrhage by nearly half (relative risk [RR], 0.55; 95% confidence interval [CI], 0.42–0.71; P<0.00001), increased the likelihood of good functional outcome by 66% (RR, 1.66; 95% CI, 1.27–2.19; P=0.0003), and also decreased the rate of shunt dependence (RR, 0.62; 95% CI, 0.42–0.93; P=0.02). IVF was not found to be associated with increased rates of ventriculitis (RR=1.46; 95% CI, 0.77–2.76; P=0.25) or rehemorrhage (RR=1.06; 95% CI, 0.66–1.70; P=0.80). We detected no evidence of publication bias. Conclusions— Our meta-analysis showed that IVF is safe and could be an effective strategy for the treatment of intraventricular hemorrhage. It may reduce mortality, improve functional outcome, and diminish the need for permanent ventricular shunting, while not increasing the risk of ventriculitis or rehemorrhage.

A comparison of severe hemodynamic disturbances between dexmedetomidine and propofol for sedation in neurocritical care patients

Objective:Dexmedetomidine and propofol are commonly used sedatives in neurocritical care as they allow for frequent neurologic examinations. However, both agents are associated with significant hemodynamic side effects. The primary objective of this study is to compare the prevalence of severe hemodynamic effects in neurocritical care patients receiving dexmedetomidine and propofol. Design:Multicenter, retrospective, propensity-matched cohort study. Setting:Neurocritical care units at two academic medical centers with dedicated neurocritical care teams and board-certified neurointensivists. Patients:Neurocritical care patients admitted between July 2009 and September 2012 were evaluated and then matched 1:1 based on propensity scoring of baseline characteristics. Interventions:Continuous sedation with dexmedetomidine or propofol. Measurements and Main Results:A total of 342 patients (105 dexmedetomidine and 237 propofol) were included in the analysis, with 190 matched (95 in each group) by propensity score. The primary outcome of this study was a composite of severe hypotension (mean arterial pressure < 60 mm Hg) and bradycardia (heart rate < 50 beats/min) during sedative infusion. No difference in the primary composite outcome in both the unmatched (30% vs 30%, p = 0.94) or matched cohorts (28% vs 34%, p = 0.35) could be found. When analyzed separately, no differences could be found in the prevalence of severe hypotension or bradycardia in either the unmatched or matched cohorts. Conclusions:Severe hypotension and bradycardia occur at similar prevalence in neurocritical care patients who receive dexmedetomidine or propofol. Providers should similarly consider the likelihood of hypotension or bradycardia before starting either sedative.

CTA collateral score predicts infarct volume and clinical outcome after endovascular therapy for acute ischemic stroke: a retrospective chart review

Background Acute ischemic stroke (AIS) due to emergent large-vessel occlusion (ELVO) has a poor prognosis. Objective To examine the hypothesis that a better collateral score on pretreatment CT angiography (CTA) would correlate with a smaller final infarct volume and a more favorable clinical outcome after endovascular therapy (EVT). Methods A retrospective chart review of the University of Tennessee AIS database from February 2011 to February 2013 was conducted. All patients with CTA-proven LVO treated with EVT were included. Recanalization after EVT was defined by Thrombolysis in Cerebral Infarction (TICI) score ≥2. Favorable outcome was assessed as a modified Rankin Score ≤3. Results Fifty patients with ELVO were studied. The mean National Institutes of Health Stroke Scale score was 17 (2–27) and 38 of the patients (76%) received intravenous tissue plasminogen activator. The recanalization rate for EVT was 86.6%. Good clinical outcome was achieved in 32% of patients. Univariate predictors of good outcome included good collateral scores (CS) on presenting CTA (p=0.043) and successful recanalization (p=0.02). Multivariate analysis confirmed both good CS (p=0.024) and successful recanalization (p=0.009) as predictors of favorable outcome. Applying results of the multivariate analysis to our cohort we were able to determine the likelihood of good clinical outcome as well as predictors of smaller final infarct volume after successful recanalization. Conclusions Good CS predict smaller infarct volumes and better clinical outcome in patients recanalized with EVT. These data support the use of this technique in selecting patients for EVT. Poor CS should be considered as an exclusion criterion for EVT as patients with poor CS have poor clinical outcomes despite recanalization.

Posterior circulation CT angiography collaterals predict outcome of endovascular acute ischemic stroke therapy for basilar artery occlusion

Introduction The natural history of acute ischemic stroke (AIS) due to basilar artery occlusion (BAO) is poor. Endovascular reperfusion therapy (EVT) improves recanalization rates in patients with emergent large vessel intracranial occlusion. Objective To examine the hypothesis that good collateral patterns identified by pretreatment CT angiography (CTA) might be associated with favorable outcomes after EVT. Methods We conducted a retrospective chart review of patients presenting with AIS due to BAO in a tertiary care stroke center during a 4-year period. BAO was diagnosed by CTA in all cases. Admission stroke severity was documented using the National Institute of Health Stroke Scale (NIHSS) score. Pretreatment collateral score for posterior circulation was defined as follows: 0, no posterior communicating artery (PCOM); 1, unilateral PCOM; 2, bilateral PCOM. Favorable outcome was defined as modified Rankin Scale score of 0–2 at 3 months. Results A total of 21 patients with AIS due to BAO (age range 31–84 years, median admission NIHSS score: 18 points, range 2–38) underwent EVT. Eleven of 21 patients (52.4%) had bilateral PCOMs, while unilateral PCOM was seen in 3 patients (14.3%). Patients with bilateral PCOMs tended (p=0.261) to have less severe stroke at admission than those with absent/unilateral PCOM (median NIHSS score 18 vs 27 points). Neurological improvement during hospitalization (quantified by the median decrease in NIHSS score) and the rate of 3-month functional independence were greater in patients with good collaterals (16 vs 0 points (p=0.016) and 72.7% vs 0% (p=0.001)). Conclusions The presence of bilateral PCOMs on pretreatment CTA appears to be associated with more favorable outcomes in BAO treated with EVT.