Deborah Bergman

Antiplatelet Effect of Aspirin in Patients With Cerebrovascular Disease

Background and Purpose— Aspirin is used commonly to prevent ischemic strokes and other vascular events. Although aspirin is considered safe and effective, it has limited efficacy with a relative risk reduction of 20% to 25% for ischemic stroke. We sought to determine if aspirin as currently used is having its desired antiplatelet effects. Methods— We ascertained patients with cerebrovascular disease who were taking only aspirin as an antiplatelet agent. Platelet function was evaluated using a platelet function analyzer (PFA-100). PFA test results were correlated with aspirin dose, formulation, and basic demographic factors. Results— We ascertained 129 patients, of whom 32% were taking an enteric-coated aspirin preparation and 32% were taking low-dose (≤162 mg/d) aspirin. For the entire cohort, 37% of patients had normal PFA-100 results, indicating normal platelet function. For the patients taking low-dose aspirin, 56% had normal PFAs compared with 28% of those taking ≥325 mg/d of aspirin, while 65% of patients taking enteric-coated aspirin had normal PFAs compared with 25% taking an uncoated preparation (P <0.01 for both comparisons). Similar results were obtained if PFA results were analyzed using mean closure times (low-dose aspirin, 183 sec; high-dose aspirin, 233 sec; enteric-coated, 173 sec; uncoated, 235 sec; P <0.01 for comparisons). Older patients and women were less likely to have a therapeutic response to aspirin, independent of aspirin dose or formulation. Conclusions— A significant proportion of patients taking low-dose aspirin or enteric-coated aspirin have normal platelet function as measured by the PFA-100 test. If these results correlate with clinical events, they have broad implications in determining how aspirin is used and monitored.

Do efforts to decrease door-to-needle time risk increasing stroke mimic treatment rates?

SummaryAn unintended consequence of rapid thrombolysis may be more frequent treatment of stroke mimics, nonvascular conditions that simulate stroke. We explored the relationship between door-to-needle (DTN) times and thrombolysis of stroke mimics at a single academic center by analyzing consecutive quartiles of patients who were treated with IV tissue plasminogen activator for suspected stroke from January 1, 2010 to February 28, 2014. An increase in the proportion of stroke mimic patients (6.7% in each of the 1st and 2nd, 12.9% in the 3rd, and 30% in the last consecutive case quartile; p = 0.03) and a decrease in median DTN time from 89 to 56 minutes (p < 0.01) was found. As more centers reduce DTN times, the rates of stroke mimic treatment should be carefully monitored.

Impact of Poststroke Medical Complications on 30-Day Readmission Rate

BACKGROUND Some previously identified predictors of 30-day stroke readmission, including age and stroke severity, are nonmodifiable. We assessed the hypothesis that in-hospital medical complications, which are potentially modifiable, after ischemic stroke (IS) and transient ischemic attack (TIA) predict 30-day readmission. METHODS In a single-center prospective cohort study of IS and TIA patients admitted from August 1, 2012, to July 31, 2013, we identified those who survived to 30-day follow-up or died during a readmission within 30 days. Patients readmitted within 30 days of discharge were identified by telephone assessment and review of hospital records. We evaluated the association between 12 prespecified and prospectively collected poststroke medical complications and 30-day readmission adjusting for baseline characteristics, in-hospital course and treatments, and discharge status using univariable and multivariable Cox proportional hazards models. RESULTS Among 505 patients, 107 (21.2%) patients had at least 1 medical complication during hospitalization. The most common complications were urinary tract infection (8.7%), venous thromboembolism (6.1%), and pneumonia (4.6%). Seventy-eight (15.4%) patients were readmitted within 30 days. On multivariable Cox proportional hazards analysis, cardioembolic or large-artery atherosclerotic subtype (adjusted hazard ratio [HR], 1.82; 95% confidence interval [CI], 1.17-2.83) and any medical complication (adjusted HR, 1.68; 95% CI, 1.04-2.73) increased the risk of 30-day readmission. Among the 24 readmitted patients who experienced an initial medical complication, 10 (41.6%) were considered potentially preventable. CONCLUSIONS The occurrence of medical complications after IS or TIA increased the risk of 30-day all-cause readmission. Stroke patients with medical complications may be suitable for targeted interventions to prevent readmissions.

Efficacy and Safety of Novel Oral Anticoagulants in Patients with Cervical Artery Dissections

Background: American and European guidelines support antiplatelet agents and anticoagulants as reasonable treatments of cervical artery dissection (CAD), though randomized clinical trials are lacking. The utility of novel oral anticoagulants (NOAC), effective in reducing embolic stroke risk in non-valvular atrial fibrillation (NVAF), has not been reported in patients with CAD. We report on the use, safety, and efficacy of NOACs in the treatment of CAD. Methods: We retrospectively identified patients diagnosed with CAD at a single academic center between January 2010 and August 2013. Patients were categorized by their antithrombotic treatment at hospital discharge with a NOAC (dabigatran, rivaroxaban, or apixaban), traditional anticoagulant (AC: warfarin or treatment dose low-molecular weight heparin), or antiplatelet agent (AP: aspirin, clopidogrel, or aspirin/extended-release dypyridamole). Using appropriate tests, we compared the baseline medical history, presenting clinical symptoms and initial radiographic characteristics among patients in the 3 treatment groups. We then evaluated for the following outcomes: recurrent stroke, vessel recanalization, and bleeding complications. p values <0.05 were considered significant. Results: Of the 149 included patients (mean age 43.4 years; 63.1% female; 70.5% vertebral artery CAD), 39 (26.2%), 70 (47.0%), and 40 (26.8%) were treated with a NOAC, AC, and AP, respectively. More patients with severe stenosis or occlusion were treated with NOAC than with AC or AP (61.8 vs. 60.0 vs. 22.5%, p = 0.002). Other baseline clinical and radiographic findings, including the presence of acute infarction and hematoma, did not differ between the 3 treatment groups. One hundred and thirty-five (90.6%) patients had clinical follow-up (median time 7.5 months) and 125 (83.9%) had radiographic follow-up (median time 5 months) information. There were 2 recurrent strokes in the NOAC group and 1 in each of the AC and AP groups (p = 0.822). There were more major hemorrhagic events in the AC group (11.4%) compared to the NOAC (0.0%) and AP (2.5%) groups (p = 0.034). Three patients treated with NOAC and none treated with AC or AP had a worsened degree of stenosis on follow-up imaging (8.6 vs. 0.0 vs. 0.0%, p = 0.019). Conclusion: Compared to traditional anticoagulants for CAD, treatment with NOACs is associated with similar rates of recurrent stroke, fewer hemorrhagic complications, but greater rates of radiographic worsening. These data suggest that NOACs may be a reasonable alternative in the management of CAD. Prospective validation of these findings is needed.

Recurrent artery-to-artery embolism during intravenous t-PA therapy for acute ischemic stroke

AbstractIntroduction: Treatment of acute ischemic stroke with systemic thrombolysis in the presence of a proximal thrombo-embolic source carries a theoretical risk of thrombus fragmentation and recurrent embolization. Intracardiac thrombus has received the most attention as a potential source of recurrent emboli, and in the past, it was considered a relative contra-indication to tissue plaminogen activator (t-PA) treatment. More recent data show that recurrent embolization from a cardiac source during t-PA infusion is rare. Case Report: This article describes recurrent symptomatic basilar artery embolization during t-PA infusion from acute thrombus in the proximal cervical vertebral artery. Discussion: This case provides evidence that intravenous t-PA must be used cautiously in the presence of large proximal thrombo-embolic sources and that intraluminal thrombus in a large cervical artery should be considered one such source.

Preventing recurrent cerebrovascular events in patients with stroke or transient ischemic attack: the current data.

Purpose: To describe recurrent stroke in relation to the current data, treatment guidelines, diagnostic considerations, risk prevention, and management for the nurse practitioner (NP). Data sources: An extensive review of the scientific literature, clinical trials, and clinical guidelines. Conclusions: Recurrent stroke is a major health concern. A first ischemic cerebrovascular event or transient ischemic attack (TIA) is a risk factor for future strokes. Implications for practice: The risk of recurring stroke has been demonstrated in multiple studies, yet only approximately 5% of stroke patients receive appropriate therapy in a timely manner. The stroke or TIA workup should be completed quickly so that the appropriate treatments and interventions can be initiated to reduce the risk of an additional event. The etiology of the stroke and identification of personal risk factors are important because treatment depends on the specific stroke mechanism. A variety of antiplatelet trials have specific implications for stroke and recurrent stroke. Present treatments include aspirin, aspirin plus extended‐release dipyridamole and clopidogrel. The NP plays an important role in ongoing patient education about symptoms, the long‐term management of the patient, and reduction of future stroke risk.Purpose: To describe recurrent stroke in relation to the current data, treatment guidelines, diagnostic considerations, risk prevention, and management for the nurse practitioner (NP). Data sources: An extensive review of the scientific literature, clinical trials, and clinical guidelines. Conclusions: Recurrent stroke is a major health concern. A first ischemic cerebrovascular event or transient ischemic attack (TIA) is a risk factor for future strokes. Implications for practice: The risk of recurring stroke has been demonstrated in multiple studies, yet only approximately 5% of stroke patients receive appropriate therapy in a timely manner. The stroke or TIA workup should be completed quickly so that the appropriate treatments and interventions can be initiated to reduce the risk of an additional event. The etiology of the stroke and identification of personal risk factors are important because treatment depends on the specific stroke mechanism. A variety of antiplatelet trials have specific implications for stroke and recurrent stroke. Present treatments include aspirin, aspirin plus extended-release dipyridamole and clopidogrel. The NP plays an important role in ongoing patient education about symptoms, the long-term management of the patient, and reduction of future stroke risk.

A resident boot camp for reducing door-to-needle times at academic medical centers

Background: We sought to determine if a structured educational program for neurology residents can lower door-to-needle (DTN) times at an academic institution. Methods: A neurology resident educational stroke boot camp was developed and implemented in April 2013. Using a prospective database of 170 consecutive acute ischemic stroke (AIS) patients treated with IV tissue plasminogen activator (tPA) in our emergency department (ED), we evaluated the effect of the intervention on DTN times. We compared DTN times and other process measures preintervention and postintervention. p Values < 0.05 were considered significant. Results: The proportion of AIS patients treated with tPA within 60 minutes of arrival to our ED tripled from 18.1% preintervention to 61.2% postintervention (p < 0.001) with concomitant reduction in DTN time (median 79 minutes vs 58 minutes, p < 0.001). The resident-delegated task (stroke code to tPA) was reduced (75 minutes vs 44 minutes, p < 0.001), while there was no difference in ED-delegated tasks (door to stroke code [7 minutes vs 6 minutes, p = 0.631], door to CT [18 minutes in both groups, p = 0.547]). There was an increase in stroke mimics treated (6.9% vs 18.4%, p = 0.031), which did not lead to an increase in adverse outcomes. Conclusions: DTN times were reduced after the implementation of a stroke boot camp and were driven primarily by efficient resident stroke code management. Educational programs should be developed for health care providers involved in acute stroke patient care to improve rapid access to IV tPA at academic institutions.