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Objectives:The optimal timing of anticoagulation after ischemic stroke in atrial fibrillation (AF) patients is unknown. Our aim was to demonstrate the feasibility and safety of initiating dabigatran therapy within 14 days of transient ischemic attack (TIA) or minor stroke in AF patients.Patients and Methods:A prospective, multi-center registry (NCT02415855) in patients with AF treated with dabigatran within 14 days of acute ischemic stroke/TIA (National Institutes of Health Stroke Scale (NIHSS) ≤ 3) onset. Baseline and follow-up computed tomography (CT) scans were assessed for hemorrhagic transformation (HT) and graded by using European Cooperative Acute Stroke Study criteria.Results:One hundred and one patients, with a mean age of 72.4 ± 11.5 years, were enrolled. Median infarct volume was 0 ml. Median time from index event onset to dabigatran initiation was 2 days, and median baseline NIHSS was 1. Pre-treatment HT was present in seven patients. No patients developed symptomatic HT. On the day 7 CT scan, HT was present in six patients (one progressing from baseline hemorrhagic infarction type 1). Infarct volume was a predictor of incident HT (odds ratio = 1.063 [1.020–1.107], p < 0.003). All six (100%) patients with new/progressive HT were functionally independent (modified Rankin Scale (mRS) = 0–2) at 30 days, which was similar to those without HT (90%, p = 0.422). Recurrent ischemic events occurred within 30 days in four patients, two of which were associated with severe disability and death (mRS 5 and 6, respectively).Conclusion:Early dabigatran treatment did not precipitate symptomatic HT after minor stroke. Asymptomatic HT was associated with larger baseline infarct volumes. Early recurrent ischemic events may be clinically more important.

Background and Purpose— Patients with transient ischemic attack (TIA) and minor ischemic stroke are at risk for early recurrent cerebral ischemia. Anticoagulants are associated with reduced recurrence but also increased hemorrhagic transformation (HT). The safety of the novel oral anticoagulant dabigatran in acute stroke has not been evaluated. Methods— DATAS II (Dabigatran Treatment of Acute Stroke II) was a phase II prospective, randomized open label, blinded end point trial. Patients with noncardioembolic stroke/transient ischemic attack (National Institutes of Health Stroke Scale score, ≤9; infarct volume, ≤25 mL) were randomized to dabigatran or aspirin. Magnetic resonance imaging was performed before randomization and repeated at day 30. Imaging end points were ascertained centrally by readers blinded to treatment. The primary end point was symptomatic HT within 37 days of randomization. Results— A total of 305 patients, mean age 66.59±13.21 years, were randomized to dabigatran or aspirin a mean of 42.00±17.31 hours after symptom onset. The qualifying event was a transient ischemic attack in 21%, and ischemic stroke in 79% of patients. Median National Institutes of Health Stroke Scale (interquartile range) was 1 (0–2), and mean infarct volume 3.2±6.5 mL. No symptomatic HT occurred. Asymptomatic petechial HT developed in 11/142 (7.8%) of dabigatran-assigned patients and 5/142 (3.5%) of aspirin-assigned patients (relative risk, 2.301 [95% CI, 0.778–6.802]). Baseline infarct volume predicted incident HT (odds ratio, 1.07 [95% CI, 1.03–1.12]; P =0.0026). Incident covert infarcts on day 30 imaging occurred in 9/142 (6.3%) of dabigatran-assigned and 14/142 (9.8%) of aspirin-assigned patients (relative risk, 0.62 [95% CI, 0.26, 1.48]). Conclusions— Dabigatran was associated with a risk of HT similar to aspirin in acute minor noncardioembolic ischemic stroke/transient ischemic attack. Registration— URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02295826.

Chronic cerebrovascular disease and large ischemic stroke are both associated with cognitive impairment. Much less is known about the acute cognitive sequelae of transient ischemic attack (TIA). Although often overlooked, there is increasing evidence that cognitive impairment does occur following TIA. In some patients, cognitive changes persist after resolution of focal neurological deficits, but the temporal profile of these symptoms is unknown. In addition, clinical and imaging correlates of cognitive impairment after TIA have not been systematically studied. This under-studied and recognized problem has significant implications for TIA patient management. In this review, we summarize the evidence currently available and identify future research priorities.

Background and Purpose— Acute ischemic stroke patients are at risk of early recurrence. We tested the feasibility and safety of initiating dabigatran in patients, within 24 hours of minor stroke in patients without atrial fibrillation. Methods— Minor stroke patients (National Institutes of Health Stroke Scale score ≤3) without atrial fibrillation and evidence of acute infarction on magnetic resonance imaging were treated with dabigatran. Treatment began within 24 hours of onset and was continued for 30 days. The primary end point was symptomatic hemorrhagic transformation. Results— A total of 53 patients with median (interquartile range) age of 68 (57–77) years and National Institutes of Health Stroke Scale score of 1 (0–2) were enrolled. Baseline diffusion-weighted imaging volume was 0.8 (0.3–2.4) mL. No patients experienced symptomatic hemorrhagic transformation. Three patients had evidence of asymptomatic petechial hemorrhagic transformation on day 7, which remained stable at day 30, while continuing dabigatran. Conclusions— Dabigatran treatment within 24 hours of minor stroke is feasible. A larger randomized trial is required to confirm the safety and efficacy of this treatment approach. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT 01769703.

Background and Purpose— Diffusion-weighted imaging (DWI) lesion volume on magnetic resonance imaging is increasingly being used as a surrogate outcome measure in clinical trials. We aimed to characterize the evolution of DWI lesion volumes within 30 days of symptom onset after minor stroke. Methods— Minor stroke patients with DWI lesions on magnetic resonance imaging within 48 hours of symptom onset were prospectively followed with magnetic resonance imaging brain scan at 7 and 30 days. Change in the lesion volume was defined as the difference between day 30 Fluid-Attenuated Inversion Recovery and baseline DWI lesion volumes. Results— Three patterns of infarct evolution were observed: reduction (72 [63%]), no change (26 [23%]), and growth (16 [14%]). Patients with infarct reduction at 30 days had larger baseline DWI lesion volumes (2.5 [0.9–8.5] mL) than those with stable infarcts (0.5 [0.3–0.9] mL; P =0.01). Complete DWI reversal at day 30, was seen in only 6 (5.3%) patients. Conclusions— The most common pattern of infarct evolution in patients with minor stroke is a reduction in volume, but complete resolution is uncommon.

Background and Purpose— Diffusion-weighted imaging (DWI) lesions have been identified both inside and outside the perihematoma region. We tested the hypotheses that larger hematoma volumes and blood pressure reduction are associated with DWI lesions. Methods— Hematoma and perihematoma edema volumes were measured using planimetric techniques in 117 intracerebral hemorrhage (ICH) patients who underwent DWI. Perihematoma and remote DWI lesion volumes were measured using apparent diffusion coefficient thresholds for moderate (−6 mm/s) and severe (−6 mm/s) ischemia. Acute blood pressure change over the first 24 hours was calculated. Results— The median (interquartile range) time to magnetic resonance imaging was 2 (1–5) days. Median hematoma volume was 9.8 (2.6–23.0) mL, and median perihematoma edema volume was 7.0 (2.9–18.6) mL. A small portion of the perihematoma region contained tissue below the thresholds for moderate (8.0 [2.9–14.5]%) and severe ischemia (1.1 [0.3–3.5]%). Ischemic perihematoma tissue volumes were correlated with hematoma volumes ( R =0.52, P R =−0.09, P =0.38). Remote DWI lesions were found in 17 (14.5%) patients (mean volume=0.44±0.3 mL). Patients with remote DWI lesions had higher rates of antiplatelet use ( P =0.01), prior ICH ( P =0.03), lobar ICH (0.04), and larger leukoaraiosis volumes ( P =0.02). Maximal systolic blood pressure drop at 24 hours was similar in patients with (−20.5 [−55, −10] mm Hg) and without remote DWI lesions (−27 [−46, −13] mm Hg, P =0.96). Conclusions— Small DWI lesions within and outside the perihematoma region are common in primary ICH. Perihematoma DWI lesions were independently associated with larger hematoma volumes. Remote DWI lesions may be an epiphenomenon associated with the underlying microvascular pathogenesis. These data do not support a hemodynamic mechanism of ischemic injury after primary ICH.

We thank Dr Regal for his interest and comments regarding our article.1 It is important to consider delirium in the differential diagnosis of stroke and to recognize that delirium can occur in the acute phase of ischemic stroke.2 We do agree that delirium and transient ischemic attack/minor stroke patients both exhibit rapid early neurological improvement. As pointed out by Dr Regal, these conditions are distinct from dementia and minimal cognitive impairment. Unlike the patients included in Dr Regal’s study, however, our patients demonstrated …

Background Temporary and permanent cognitive changes following transient ischemic attack/minor stroke have been described previously. It is unknown if persisting cognitive deficits in these patients are correlated with acute infarction identified using magnetic resonance imaging. Aims We tested the hypothesis that persistent cognitive impairment after transient ischemic attack/minor stroke can be predicted by the volume of diffusion-weighted imaging lesions. Methods Acute transient ischemic attack/minor stroke (NIH stroke scale score ≤ 3) patients were prospectively recruited within 72 h of onset. Patients underwent Montreal cognitive assessment and magnetic resonance imaging, including diffusion-weighted imaging and Fluid-Attenuated Inverse Recovery sequences, at baseline, days 7 and 30. Cognitive testing was repeated at day 90. Diffusion-weighted imaging lesion and Fluid-Attenuated Inverse Recovery chronic white matter hyperintensity volumes were measured planimetrically. Cognitive impairment was defined a priori as Montreal cognitive assessment score Results One hundred fifteen patients were imaged at a median (inter-quartile range) of 24.0 (16.6) h after onset. Acute ischemic lesions were present in 91 (79%) patients. Cognitive impairment rates were similar in patients with (47/91, 52%) and without diffusion-weighted imaging lesions (13/24, 54%; p = 0.83). Although linear regression indicated no relationship between acute diffusion-weighted imaging lesion volume and day 30 Montreal cognitive assessment scores (β = −0.163, [−2.243, 0.334], p = 0.144), white matter hyperintensity volumes at baseline were predictive of persistent cognitive deficits after 30 days (β = 2.24, [1.956, 45.369], p = 0.005). Conclusions In most transient ischemic attack/minor stroke patients who suffer acute cognitive impairment post event, deficits are temporary. Deficits after 30 days of onset are correlated with chronic white matter hyperintensity, suggesting subclinical cognitive impairment and/or impaired ability to compensate for the effects of acute ischemic infarcts.