ABSTRACT
Brain imaging is essential to the clinical management of patients with ischemic stroke. Timely and accessible neuroimaging, however, can be limited in clinical stroke pathways. Here, portable magnetic resonance imaging (pMRI) acquired at very low magnetic field strength (0.064 T) is used to obtain actionable bedside neuroimaging for 50 confirmed patients with ischemic stroke. Low-field pMRI detected infarcts in 45 (90%) patients across cortical, subcortical, and cerebellar structures. Lesions as small as 4 mm were captured. Infarcts appeared as hyperintense regions on T2-weighted, fluid-attenuated inversion recovery and diffusion-weighted imaging sequences. Stroke volume measurements were consistent across pMRI sequences and between low-field pMRI and conventional high-field MRI studies. Low-field pMRI stroke volumes significantly correlated with stroke severity and functional outcome at discharge. These results validate the use of low-field pMRI to obtain clinically useful imaging of stroke, setting the stage for use in resource-limited environments.
ABSTRACT
BACKGROUND: We aimed to compare the outcome of acute ischemic stroke (AIS) patients who received endovascular thrombectomy (EVT) with confirmed COVID-19 to those without. METHODS: We performed a retrospective analysis using the Vizient Clinical Data Base and included hospital discharges from April 1 to July 31 2020 with ICD-10 codes for AIS and EVT. The primary outcome was in-hospital death and the secondary outcome was favorable discharge, defined as discharge home or to acute rehabilitation. We compared patients with laboratory-confirmed COVID-19 to those without. As a sensitivity analysis, we compared COVID-19 AIS patients who did not undergo EVT to those who did, to balance potential adverse events inherent to COVID-19 infection. RESULTS: We identified 3165 AIS patients who received EVT during April to July 2020, in which COVID-19 was confirmed in 104 (3.3%). Comorbid COVID-19 infection was associated with younger age, male sex, diabetes, black race, Hispanic ethnicity, intubation, acute coronary syndrome, acute renal failure, and longer hospital and intensive care unit length of stay. The rate of in-hospital death was 12.4% without COVID-19 vs 29.8% with COVID-19 (P<0.001). In mixed-effects logistic regression that accounted for patient clustering by hospital, comorbid COVID-19 increased the odds of in-hospital death over four-fold (OR 4.48, 95% CI 3.02 to 6.165). Comorbid COVID-19 was also associated with lower odds of a favorable discharge (OR 0.43, 95% CI 0.30 to 0.61). In the sensitivity analysis, comparing AIS patients with COVID-19 who did not undergo EVT (n=2139) to the AIS EVT patients with COVID-19, there was no difference in the rate of in-hospital death (30.6% vs 29.8%, P=0.868), and AIS EVT patients had a higher rate of favorable discharge (32.4% vs 47.1%, P=0.002). CONCLUSION: In AIS patients treated with EVT, comorbid COVID-19 infection was associated with in-hospital death and a lower odds of favorable discharge compared with patients without COVID-19, but not compared with AIS patients with COVID-19 who did not undergo EVT. AIS EVT patients with COVID-19 were younger, more likely to be male, have systemic complications, and almost twice as likely to be black and over three times as likely to be Hispanic.