James Conners

Intravenous thrombolysis in a stroke patient taking dabigatran.

We describe the use of intravenous thrombolysis with recombinant tissue plasminogen activator (IV-rtPA) in a patient with concomitant dabigatran use. A 64-year-old man with a history of coronary artery disease, pacemaker placement, and atrial fibrillation developed acute right arm/face weakness and dysarthria. He was unable to list his home medications. His platelet count was 167 × 10(9)/L (normal 150-399 × 10(9)/L), and his activated partial thromboplastin time (aPTT) was 37.6 seconds (normal 24.0-33.0 seconds). His international normalized ratio (INR) was 1.1. He received IV-rtPA at 3 hours and 25 minutes after the onset of symptoms. After IV-rtPA was administered, it was discovered that the patient had been taking dabigatran for 2 months. After IV-rtPA, the patient developed severe superficial left arm ecchymoses but remained without cerebral complications. On poststroke day 1, his fibrinogen level was low at 63 mg % (normal 190-395 mg %), his aPTT was normal at 33, and his INR was elevated at 1.72 but decreased to 1.18 on the following day. Repeat computed tomographic imaging of his brain confirmed a left middle cerebral artery ischemic cortical infarct. We report a case of an acute stroke patient taking dabigatran who received IV-rtPA. In the acute stroke setting, clinicians should be aware of the increasing use of dabigatran in patients with atrial fibrillation when considering IV-rtPA. Although aPTT does not provide a linear response to dabigatran therapy, the presence of a completely normal PTT may exclude therapeutic dabigatran anticoagulation.

Perfusion-based selection for endovascular reperfusion therapy in anterior circulation acute ischemic stroke

The authors attempted to determine if reperfusion therapy for anterior circulation acute stroke based on MR perfusion resulted in better outcomes at 3 months than that based on noncontrast CT. Perfusion imaging-selected patients had a better outcome than those selected with only noncontrast CT but MR perfusion- and CT perfusion-selected patients had similar outcomes. In this multicenter study, patients with acute stroke who underwent perfusion imaging were more than 2-fold more likely to have good outcomes following endovascular reperfusion therapy BACKGROUND AND PURPOSE: Controversy exists about the role of perfusion imaging in patient selection for endovascular reperfusion therapy in acute ischemic stroke. We hypothesized that perfusion imaging versus noncontrast CT- based selection would be associated with improved functional outcomes at 3 months. MATERIALS AND METHODS: We reviewed consecutive patients with anterior circulation strokes treated with endovascular reperfusion therapy within 8 hours and with baseline NIHSS score of ≥8. Baseline clinical data, selection mode (perfusion versus NCCT), angiographic data, complications, and modified Rankin Scale score at 3 months were collected. Using multivariable logistic regression, we assessed whether the mode of selection for endovascular reperfusion therapy (perfusion-based versus NCCT-based) was independently associated with good outcome. RESULTS: Two-hundred fourteen patients (mean age, 67.2 years; median NIHSS score, 18; MCA occlusion 74% and ICA occlusion 26%) were included. Perfusion imaging was used in 76 (35.5%) patients (39 CT and 37 MR imaging). Perfusion imaging–selected patients were more likely to have good outcomes compared with NCCT-selected patients (55.3 versus 33.3%, P = .002); perfusion selection by CT was associated with similar outcomes as that by MR imaging (CTP, 56.; MR perfusion, 54.1%; P = .836). In multivariable analysis, CT or MR perfusion imaging selection remained strongly associated with good outcome (adjusted OR, 2.34; 95% CI, 1.22–4.47), independent of baseline severity and reperfusion. CONCLUSIONS: In this multicenter study, patients with acute ischemic stroke who underwent perfusion imaging were more than 2-fold more likely to have good outcomes following endovascular reperfusion therapy. Randomized studies should compare perfusion imaging with NCCT imaging for patient selection for endovascular reperfusion therapy.

Predictors of false-positive stroke thrombectomy transfers

Background Most patients with large vessel occlusion (LVO) stroke need to be transferred to receive thrombectomy. To save time, the decision to transfer often relies on clinical scales as a surrogate for LVO rather than imaging. However, clinical scales have been associated with high levels of diagnostic error. The aim of this study is to define the susceptibility to overdiagnosis of our current transfer decision process by measuring the rate of non-treatment transfers, the most common reasons for no treatment and potential predictors. Methods Clinical and transfer data on consecutive patients transferred to a single endovascular capable centre for possible thrombectomy via stroke code activation were retrospectively reviewed. Whether patients underwent the procedure, why they did not undergo the procedure, and other clinical and logistical predictors were recorded. χ2 tests and multivariate logistic regression analysis were performed. Results From 2015 to 2016, 105/192 transferred patients (54%) did not undergo thrombectomy and the most common reason was absence of a LVO found on CTA after transfer (71/104 (68%)). 14/16 (88%) with a National Institutes of Health Stroke Scale (NIHSS) score <10 did not undergo thrombectomy while 41/78 (52%) with a NIHSS>20 underwent thrombectomy (p<0.001). Helicopter use was associated with no treatment (p=0.004) while arrival within 5 hours was associated with treatment (p<0.001). Conclusions Clinical scales appear to overdiagnose LVO and may be responsible for the majority of our stroke code transfers not undergoing thrombectomy. Primary stroke centres therefore have reason to develop the capability to rapidly acquire and interpret a CTA in patients with suspected LVO prior to transfer. Such efforts may reduce the costs associated with unnecessary thrombectomy transfers.

Elevated International Normalized Ratio as a Manifestation of Post-thrombolytic Coagulopathy in Acute Ischemic Stroke

BACKGROUND A serious complication of intravenous tissue plasminogen activator (tPA) in acute ischemic stroke is hemorrhage. Coagulation factors that may potentially increase the risk of bleeding after tPA are not well understood. METHODS We retrospectively reviewed 284 acute ischemic stroke patients who received tPA. Post-tPA coagulopathy was defined as a documented elevation of international normalized ration (INR) > 1.5 within 24 hours after IV tPA without a known cause. RESULTS We identified 21 (7.4%) patients with an elevated INR post-thrombolysis. The mean age was 68.3 years (standard deviation ± 11.9) and 57% were male. The mean initial National Institutes of Health Stroke Scale (pre-tPA) was 15.8 (range, 4-35). Liver disease or alcohol abuse was noted in 19%. There were 2 tPA protocol violations who received more than 90 mg tPA. The mean post-tPA INR was 2.03 (range, 1.5-4.7) and the elevation in INR was documented within a mean 5.4 hours (range, 1-15) after tPA initiation. Repeat INR levels returned to normal during their hospital stay in 19 patients. Hypofibrinogenemia was noted in 10 of 12 patients who had fibrinogen levels drawn within 48 hours after tPA initiation and in all 7 patients with fibrinogen levels drawn the same time as the elevated INR. Among the 6 patients with bleeding complications, 2 patients had symptomatic intracerebral hemorrhage. CONCLUSIONS We report an under-recognized early transient coagulopathy associated with elevated INR in stroke patients after treatment with tPA.

Three-Month Outcomes Are Poor in Stroke Patients with Cancer Despite Acute Stroke Treatment

INTRODUCTION Stroke risk is increased in cancer patients. Prognosis in these patients is poor, with higher in-hospital mortality and increased subsequent mortality. However, data on stroke in cancer patients are limited, specifically regarding acute stroke treatment and functional outcomes. We aim to determine the functional outcomes of cancer patients admitted with acute stroke. MATERIALS AND METHODS We retrospectively reviewed patients carrying a diagnosis of cancer who were admitted with acute ischemic stroke between March 2013 and February 2016. Demographics, cerebrovascular risk factors, stroke characteristics including acute treatment, and characteristics of their cancer history and treatment were abstracted. The primary outcome measures included in-hospital mortality and 3-month functional outcome (as assessed by the modified Rankin Scale [mRS] score, with mRS scores of 3-6 considered poor functional outcome). Further outcome measures included length of stay and discharge destination. FINDINGS Forty-nine patients met the inclusion criteria, with a median admission National Institutes of Health Stroke Scale score of 8. Twelve patients (24.4%) underwent acute stroke treatment. The most common stroke etiology was hypercoagulability of malignancy (21, 42.9%). The three-month mortality was 46.9%; half of survivors had poor functional outcome. Functional outcomes did not differ by cancer type, stage, or year since diagnosis; on multivariate analysis only high admission NIHSS score was associated with poor functional outcome (P = .002). CONCLUSION Nearly half of patients with cancer and stroke die within 3 months, and functional outcome is poor for 50% of 3-month survivors despite consideration of acute stroke treatment. Future research should address the role of hypercoagulability in the outcome prediction of stroke patients with cancer.

Telestroke in an Urban Setting

BACKGROUND Telestroke is a viable alternative in rural areas where neurologists or stroke expertise is unavailable. Urban applications of telestroke have not been previously described. MATERIALS AND METHODS All patients evaluated using remote telestroke technology at four urban spoke hospitals between March 2011 and March 2013 were included in this analysis. Telestroke services were provided by vascular fellowship-trained neurologists at one academic stroke center. Patient characteristics, time to initiation of consult, and treatment decisions were prospectively recorded. Stroke triage protocols and thrombolysis rates prior to initiation of telestroke were also obtained. RESULTS Four hundred ninety-eight patients were evaluated during the study period; mean age was 64.5 years, and 60.4% were female. Median time from initial emergency room call to start of teleconsult was 5 (range, 1-51) minutes. Average length of teleconsult was 30 minutes. Technical difficulties occurred in 80 (16.0%) teleconsults, but only 1 was major. Daytime calls (8 a.m.-5 p.m. Monday-Friday) accounted for 38.2% of teleconsults. Two hundred eighty-one patients (56.4%) were determined by teleconsult to have an acute ischemic stroke or transient ischemic attack (TIA). In 72 patients (14.5% overall; 25.6% of all ischemic stroke/TIA patients), intravenous alteplase (tissue plasminogen activator) was recommended. Transfer to the hub hospital occurred in 75 patients (15.1%). CONCLUSIONS Telestroke is a rapid and effective way to assess patients with suspected acute stroke in an urban setting. Its use may increase access to stroke neurologists and improve thrombolysis rates where competing responsibilities may delay, prevent, and even dissuade on-site evaluation by neurologists.

Response to the letter by Lee et al.

I readwith great interest the case report ofLee et al describing the use of recombinant tissue plasminogen activator in an acute ischemic stroke survivor with a normal activated partial thromboplastin time (aPTT) receiving dabigatran therapy. Based on their experience, the authors concluded that a normal aPTT value may exclude the presence of a residual pharmacologic effect of dabigatran. Thrombin time and ecarin clotting time are considered sensitive tests for assessing the anticoagulant effect of dabigatran; however, these tests have not been validated in large cohorts and are not available in most medical centers. In agreement with the authors, some specialists suggest circumventing this shortcoming by using the aPTT and indicate that patients with normal aPTT values treated with dabigatran can be assumed to have no meaningful residual anticoagulation effect. It also has been suggested that aPTT can be useful in guiding treatment of dabigatran-treated individuals with life-threatening hemorrhage. Increasing doses of dabigatran prolong the aPTT in a nonlinear fashion. This test assesses the intrinsic coagulation pathway but provides no information about pertinent variables that contribute to hemostasis, such as clot strength and elasticity. Individuals receiving dabigatran may have normal conventional plasmabased coagulation studies but a residual antihemostatic effect, as evidenced by rapid thrombelastography. In this scenario, practicing physicians should exercise caution when using the aPTT to guide treatment in patients being treated with dabigatran, given that normal values might not necessarily denote intact hemostasis.

Mobile Real-time Tracking of Acute Stroke Patients and Instant, Secure Inter-team Communication - the Join App

Purpose The primary correlate to survival and preservation of neurologic function in patients suffering from an acute ischemic stroke is time from symptom onset to initiation of therapy and reperfusion. Communication and coordination among members of the stroke team are essential to maximizing efficiency and subsequently early reperfusion. In this work, we aim to describe our preliminary experience using the Join mobile application as a means to improve interdisciplinary team communication and efficiency. Materials and Methods We describe our pilot experience with the initiation of the Join mobile application between July 2015 and July 2016. With this application, a mobile beacon is transported with the patient on the ambulance. Transportation milestone timestamps and geographic coordinates are transmitted to the treating facility and instantly communicated to all treatment team members. The transport team / patient can be tracked en route to the treating facility. Results During our pilot study, 62 patients were triaged and managed using the Join application. Automated time-stamping of critical events, geographic tracking of patient transport and summary documents were obtained for all patients. Treatment team members had an overall favorable impression of the Join application and recommended its continued use. Conclusion The Join application is one of several components of a multi-institutional, interdisciplinary effort to improve the treatment of patients with acute ischemic stroke. The ability of the treatment team to track patient transport and communicate with the transporting team may improve reperfusion time and, therefore, improve neurologic outcomes.

Response to Letter to the Editor by Dr. Witsch et al.

We thank Dr. Witsch et al. for their kind interest in our recent article on ‘‘Risk Stratification for the In-Hospital mortality in Subarachnoid Hemorrhage: The HAIR score’’. We acknowledge that between score 6 and 7, mortality was essentially the same (in our data, 82.1 vs. 83.3 %), and Dr. Witsch reports similar numbers, albeit with a slightly decreased mortality (79.7 vs. 78.4 %). This small reversal is likely due to low power as the number of patients in the moribund subgroups (score 6, 7, 8) were likely relatively small compared to the overall cohort. In our data, there were only 6 patients with a score of 7 and no patients with a score of 8. Recognizing this, we chose to validate the HAIR score in our second cohort using a simplified risk stratification with low (score 0–2), moderate (score 3–5), and high (score 6–8), and clinically, it may be more meaningful to categorize patients this way. Of interest, Dr. Witsch’s findings included patients with the maximum HAIR score of 8, which was associated with 100 % mortality. Inclusion of patients in the highest subgroup is important and appears to be consistent with the HAIR score prediction. Dr. Witsch’s findings of an area under the ROC-curve of 0.9 indicates robust performance in discrimination overall, and we are pleased that the HAIR score has been externally validated in a separate cohort of over 1,600 subarachnoid hemorrhage patients.

Periprocedural Risk of Stroke Is Elevated in Patients with End-Stage Renal Disease on Hemodialysis

Objective: To describe the most common clinical factors and stroke etiologies in a case series of patients with end-stage renal disease on hemodialysis (ESRD/HD) with transient ischemic attack (TIA) or ischemic stroke (IS). Background: Prior studies have shown that patients on HD are at an elevated risk of stroke, but these studies have focused on the overall stroke risk. This case series sought to determine the percentage of acute ischemic events that occur during or immediately after HD. Methods: ICD-9 codes were used to identify IS and TIA patients with ESRD/HD admitted to the stroke service from August 22, 2011, to June 21, 2014. Charts were reviewed to determine the age, sex, and race/ethnicity of the cohort. TIA/IS diagnosis was confirmed by a vascular neurologist. Clinical factors were assessed, including: onset during or shortly after HD, defined as occurring within 12 h of HD; the presence of a lesion on diffusion-weighted MRI; hypotension, hyponatremia, or hypoglycemia at symptom onset; the stroke etiology; the presence of focal neurologic deficits; whether the patient was in the window period for intravenous tissue plasminogen activator (IVtPA) upon presentation, and whether the patient received IVtPA. Results: We identified 34 ESRD/HD patients with a diagnosis of TIA/stroke in the specified time period. A majority of patients (70.6%) were African American. Patient age ranged from 32 to 84 years, with a median age of 67 years. Twenty-seven patients (79.4%) had confirmed ischemic infarcts on diffusion-weighted MRI. Seven patients (20.6%) were diagnosed with TIA. In 13 patients (38.2%), symptom onset occurred during or shortly after HD. Of these 13 patients, 8 (61.5%) had symptom onset during HD. Three patients (8.8%) had documented hypotension near the time of symptom onset, and 2 (5.9%) were hyponatremic on presentation to the emergency department. The distribution of stroke etiologies was as follows: 4 (11.8%) watershed distribution, 1 (2.9%) large artery atherosclerosis, 2 (20.6%) small vessel disease, 10 (29.4%) cardioembolic, and 9 (26.5%) cryptogenic. In 28 patients (82.4%), focal neurologic deficits were observed on presentation. Nine patients (26.5%) arrived within the window period for IVtPA, and 4 (11.8%) were eligible and received IVtPA. Conclusions: Of all patients with ESRD on HD admitted to the stroke service over the study period, over one third (38.3%) had the onset of their ischemic event during or shortly after HD, and nearly one quarter (23.5%) had the onset during HD. While clinicians may be tempted to attribute neurologic changes after HD to metabolic etiologies, they should also be aware that HD represents a period of elevated risk for acute ischemia.