A Comparison of Cooling Techniques to Treat Cardiac Arrest Patients with Hypothermia

Introduction. We sought to compare the performance of endovascular cooling to conventional surface cooling after cardiac arrest. Methods. Patients in coma following cardiopulmonary resuscitation were cooled with an endovascular cooling catheter or with ice bags and cold-water-circulating cooling blankets to a target temperature of 32.0–34.0°C for 24 hours. Performance of cooling techniques was compared by (1) number of hourly recordings in target temperature range, (2) time elapsed from the written order to initiate cooling and target temperature, and (3) adverse events during the first week. Results. Median time in target temperature range was 19 hours (interquartile range (IQR), 16–20) in the endovascular group versus. 10 hours (IQR, 7–15) in the surface group (P = .001). Median time to target temperature was 4 (IQR, 2.8–6.2) and 4.5 (IQR, 3–6.5) hours, respectively (P = .67). Adverse events were similar. Conclusion. Endovascular cooling maintains target temperatures better than conventional surface cooling

Frequency of Blood-Brain Barrier Disruption Post-Endovascular Therapy and Multiple Thrombectomy Passes in Acute Ischemic Stroke Patients

Background and Purpose-The high prevalence of hyperintense acute reperfusion marker (HARM) seen after endovascular therapy is suggestive of blood-brain barrier disruption and hemorrhage risk and may be attributable to multiple thrombectomy passes needed to achieve recanalization. Methods-Patients with acute stroke were included if they were screened from January 2015 through February 2019, received an acute ischemic stroke diagnosis involving the anterior circulation, treated with or without IV tPA (intravenous tissue-type plasminogen activator), consented to the NINDS Natural History Study, and imaged with a baseline magnetic resonance imaging before receiving endovascular therapy. Consensus image reads for HARM and hemorrhagic transformation were performed. Good clinical outcome was defined as 0-2 using the latest available modified Rankin Scale score. Results-Eighty patients met all study criteria and were included in the analyses. Median age was 65 years, 64% female, 51% black/African American, median admit National Institutes of Health Stroke Scale=19, 56% treated with IV tPA, and 84% achieved Thrombolysis in Cerebral Infarction score of 2b/3. Multiple-pass patients had significantly higher rates of severe HARM at 24 hours (67% versus 29%; P=0.001), any hemorrhagic transformation (60% versus 36%; P=0.04) and poor clinical outcome (67% versus 36%; P=0.008). Only age (odds ratio, 1.1; 95% CI, 1.01-1.12; P=0.022) and severe HARM at 24 hours post-endovascular therapy were significantly associated with multiple passes (odds ratio, 7.2; 95% CI, 1.93-26.92; P=0.003). Conclusions-In this exploratory study, multiple thrombectomy passes are independently associated with a significant increase in blood-brain barrier disruption detected at 24 hours. Patients with HARM post-endovascular therapy had a \u3e7-fold increase in the odds of having multiple-versus single-pass thrombectomy. Clinical Trial Registration-URL: https://www.clinicaltrials.gov. Unique identifier: NCT00009243

Estimating Perfusion Deficits in Acute Stroke Patients Without Perfusion Imaging

BACKGROUND: Perfusion weighted imaging (PWI) is critical for determining whether stroke patients presenting in an extended time window are candidates for mechanical thrombectomy. However, PWI is not always available. Fluid-attenuated inversion recovery hyperintense vessels (FHVs) are seen in patients with a PWI lesion. We investigated whether a scale measuring the extent FHV could serve as a surrogate for PWI to determine eligibility for thrombectomy. METHODS: The National Institutes of Health (NIH) FHV score was developed to quantify the burden of FHV and applied to magnetic resonance imaging scans of stroke patients with fluid-attenuated inversion recovery and perfusion imaging. The NIH-FHV was combined with the diffusion weighted image volume to estimate the diffusion-perfusion mismatch ratio. Linear regression was used to compare PWI volumes and mismatch ratios with estimates from the NIH-FHV score. Receiver operating characteristic analysis was used to test the ability of the NIH-FHV score to identify a significant mismatch. RESULTS: There were 101 patients included in the analysis, of whom 78% had a perfusion deficit detected on PWI with a mean lesion volume of 47 (±59) mL. The NIH-FHV score was strongly associated with the PWI lesion volume (\u3c0.001; R=0.32; β-coefficient, 0.57). When combined with diffusion weighted image lesion volume, receiver operating characteristic analysis testing the ability to detect a mismatch ratio ≥1.8 using the NIH-FHV score resulted in an area under the curve of 0.94. CONCLUSIONS: The NIH-FHV score provides an estimate of the PWI lesion volume and, when combined with diffusion weighted imaging, may be helpful when trying to determine whether there is a clinically relevant diffusion-perfusion mismatch in situations where perfusion imaging is not available. Further studies are needed to validate this approach

MRI-based thrombolytic therapy in patients with acute ischemic stroke presenting with a low NIHSS

ObjectiveTreatment of patients with stroke presenting with minor deficits remains controversial, and the recent Potential of rtPA for Ischemic Strokes with Mild Symptoms (PRISMS) trial, which randomized patients to thrombolysis vs aspirin, did not show benefit. We studied the safety and efficacy of thrombolysis in a population of patients with acute stroke presenting with low NIH Stroke Scale (NIHSS) scores screened using MRI.MethodsThe NIH Natural History of Stroke database was reviewed from January 2006 to December 2016 to identify all patients with an initial NIHSS score =5 who received thrombolysis within 4.5 hours of symptom onset after being screened with MRI. The 24-hour postthrombolysis MRIs were reviewed for hemorrhagic transformation. Primary outcomes were symptomatic intracranial hemorrhage (sICH) and favorable 90-day outcome modified Rankin Scale score 0-1. Subgroup analysis was performed on patients who would have been eligible for the PRISMS trial, which enrolled patients with a nondisabling neurologic deficit.ResultsA total of 121 patients were included in the study with a median age of 65 and an NIHSS score of 3; 63% were women. The rate of any hemorrhagic transformation was 13%, with 11% of them being limited to petechial hemorrhage. The rate of sICH was \u3c1%. Sixty-six patients had 90-day outcome data; of those, 74% had a favorable outcome. For the subgroup of 81 PRISMS-eligible patients, none experienced sICH. Fifty of these patients had 90-day outcome data; of these, 84% had a favorable outcome.ConclusionsThrombolytic therapy was safe in our patients with stroke with minor deficits who were initially evaluated by MRI. Future studies of this population may benefit from MRI selection.Classification of evidenceThis study provides Class IV evidence that for patients with acute ischemic stroke and NIHSS =5 screened with MRI, IV tissue plasminogen activator is safe

Rapid Apparent Diffusion Coefficient Evolution after Early Revascularization: A Potential Marker of Secondary Injury?

Background and Purpose-In this era of endovascular therapy (EVT) with early, complete recanalization and reperfusion, we have observed an even more rapid apparent diffusion coefficient (ADC) normalization within the acute ischemic lesion compared with the natural history or IV-tPA-treated patient. In this study, we aimed to evaluate the effect of revascularization on ADC evolution within the core lesion in the first 24 hours in acute ischemic stroke patients. Methods-This retrospective study included anterior circulation acute ischemic stroke patients treated with EVT with or without intravenous tPA (IVT) from 2015 to 2017 compared with a consecutive cohort of IVT-only patients treated before 2015. Diffusion-weighted imaging and ADC maps were used to quantify baseline core lesions. Median ADC value change and core reversal were determined at 24 hours. Diffusion-weighted imaging lesion growth was measured at 24 hours and 5 days. Good clinical outcome was defined as modified Rankin Scale score of 0 to 2 at 90 days. Results-Twenty-five patients (50%) received IVT while the other 25 patients received EVT (50%) with or without IVT. Between these patient groups, there were no differences in age, sex, baseline National Institutes of Health Stroke Scale, interhospital transfer, or IVT rates. Thirty-two patients (64%) revascularized with 69% receiving EVT. There was a significant increase in median ADC value of the core lesion at 24 hours in patients who revascularized compared with further ADC reduction in nonrevascularization patients. Revascularization patients had a significantly higher rate of good clinical outcome at 90 days, 63% versus 9% (P=0.003). Core reversal at 24 hours was significantly higher in revascularization patients, 69% versus 22% (P=0.002). Conclusions-ADC evolution in acute ischemic stroke patients with early, complete revascularization, now more commonly seen with EVT, is strikingly different from our historical understanding. The early ADC normalization we have observed in this setting may include a component of secondary injury and serve as a potential imaging biomarker for the development of future adjunctive therapies. Clinical Trial Registration-URL: https://www.clinicaltrials.gov. Unique identifier: NCT00009243