Impact of the COVID-19 pandemic on acute ischemic stroke medical care: a prospective study

INTRODUCTION: Acute ischemic stroke (AIS) is not uncommon in patients with novel coronavirus infection. During the COVID-19 pandemic, an increase of the frequency of adverse clinical and functional outcomes of AIS was noted. OBJECTIVE: The recent study was to evaluate the impact of the COVID-19 pandemic on the clinical and diagnostic characteristics of patients with AIS, as well as on the results of various types of treatment. MATERIALS AND METHODS: The prospective study included 460 patients with AIS after systemic or selective thrombolysis, thromboextraction and combination of thromboextraction with thrombolysis and stenting, hospitalized in 2019–2022: 55 patients in 2019, and in 2020–2022 — 405 patients. All patients were clinically evaluated using NIHSS and Rankin scales. Instrumental data included: assessment of computed tomography (CT) lesion size, extracranial and transcranial Duplex ultrasound (DUS) and computed angiography. Patients who received invasive treatment (thromboextraction, including in combination with thrombolysis or stenting) underwent cerebral angiography (CA). The characteristics of cerebral hemodynamics before and after the use of various types of treatment, clinical and functional outcomes were subject for comparison. Statistics: The statistical software Statistica 12.0, SPSS Statistics 17.0 were used. Normality of distribution was assessed using the Shapiro–Wilks test. Comparison of groups based on quantitative parameters was carried out using the Mann–Whitney U test. When testing statistical hypotheses, the acceptable level of error of the first type was considered to be a value not exceeding 0.05. To assess the correlation between parameters, the Spearman method was used. RESULTS: During the pandemic of COVID-19, patients with AIS were younger, had lower percentage of comorbidities and a higher NIHSS score. A significantly lower rate of favorable clinical and functional outcomes was obtained during the pandemic compared to the period before the pandemic, including after the use of invasive treatment methods: only 47% of patients had clinical improvement during the pandemic, while in 2019 the proportion of favorable outcomes was 64% (p=0.003). There was an increase in the share of pulmonary embolism and pneumonia in the structure of mortality from AIS during the pandemic (25% in the period before the pandemic vs 38% during the pandemic). Duplex ultrasound of cerebral arteries demonstrated high comparability with angiography data (correlation coefficient with invasive methods 0.84). DISCUSSION: According to the literature data, strokes are not uncommon in patients with COVID-19, especially in those with severe disease and risk factors. The authors consider thrombosis and/or thromboembolism of cerebral arteries to be possible ways of cerebral ischemia. According to Russian scientists, from the beginning of the pandemic, a significant increase in the incidence of ischemic stroke of varying severity was noted. The statistical pattern we identified confirms the data from literature sources that when infected with the SARS-CoV-2 virus, the brain and cerebral arteries are target organs. It is significant for clinical practice that we have evaluated the clinical and instrumental characteristics of these lesions in relatively homogeneous gender, age and clinical groups. CONCLUSION: The incidence of favorable clinical and functional outcomes during the pandemic was significantly lower compared to the pre-pandemic period. Complete and partial restoration of blood flow, as well as a decrease in the ischemic focus, were significantly more common before the pandemic. The effectiveness of invasive methods of cerebral revascularization during the pandemic were also lower. Duplex ultrasound serves as a reliable method not only for primary diagnosis, but also for dynamic monitoring. Initial changes in hemodynamics in patients with AIS before and during the pandemic did not differ significantly and were represented by hypoperfusion with a decrease in peripheral resistance. In 2020–2022 after treatment, hypoperfusion was observed significantly more often, which can be considered as one of the reasons for the less favorable clinical and functional outcomes obtained during the pandemic.