Clinical characteristics of COVID-19 patients with or without stroke
The essential clinical information of COVID-19 patients is summarized in Table 1. A total of 2474 cases were included in this study, with a mean age of 61.0±15.7 years. The mean age of patients in the stroke group was significantly older than that in the nonstroke group (P< .001). Specifically, patients older than 60 years were more frequently observed in the stroke group than in the nonstroke group (P<.001). However, there was no difference in sex among groups (P=.558). The presence of comorbidities (hypertension, diabetes and heart disease) was more common among patients with stroke (all P<.001). Moreover, the stroke patients showed a higher incidence of consciousness disorder than nonstroke patients (P<.001), while the other common symptoms, such as cough, shortness of breath, and diarrhea, were similar. Stroke patients were more likely to have low fingertip oxygen saturation than nonstroke patients (P<.001).
The stroke patients were further divided into two subgroups according to the time point of stroke onset: patients with previous stroke and new stroke. The detailed clinical characteristics for patients in different subgroups are listed in Table 1. Generally, there were 88 patients with previous stroke and 25 cases with newly identified stroke. In comparison to nonstroke patients, both previous and new stroke patients showed similar incidences of common symptoms, such as cough, shortness of breath, diarrhea and fever, but a higher incidence of consciousness disorder than nonstroke patients (all P<.001). The proportion of patients with headache or dizziness (44.4% vs 18.0%, P=.01) was higher for new stroke patients than nonstroke patients. Previous stroke patients were more likely to have low fingertip oxygen saturation (<93%) than nonstroke patients (23.1% vs 11.5%, P<.001).
Figure 1 shows representative radiological images of COVID-19 patients with new-onset and previous stroke.
Laboratory parameters of COVID-19 patients with and without stroke
Table 2 shows the laboratory findings of patients with and without stroke. Previous and new stroke patients exhibited more prevalent neutrophilia (33.0% and 48.0% vs 21.1%, P<.001, respectively), lymphocytopenia (58% and 76% vs 31.2%, P<.001, respectively) and anemia (25% and 28% vs 8.5%, P<.001, respectively) than the nonstroke group. Blood levels of cytokines and infection-related factors were detected in a certain proportion of patients with or without stroke, including IL-1β, TNF-α, IL-8, IL-2R, IL-10 and hsCRP. An abnormal concentration of IL-6 was more frequently found in previous and new stroke patients (68.3% and 87.0% vs 42.4%, P<.001, respectively). More previous and new stroke cases had markedly higher concentrations of myohemoglobin (MG, 30.4% and 45% vs 12.7%, P<.001, respectively), N terminal pro-brain natriuretic peptide (NT pro-BNP, 78.2% and 91.3% vs 50.5%, P<.001, respectively), blood urea nitrogen (BUN, 44.8% and 44% vs 16.5%, P<.001, respectively) and creatinine (Cr, 44.8% and 44% vs 13%, P<.001, respectively) than nonstroke patients. In addition, elevated concentrations of cardiac troponin I (cTnI, 26.4% vs 11.3%, P<.001), creatine kinase-myoglobin (CK-MB, 10.1% vs 4.7%, P=.028) and decreased levels of albumin (42.5% vs 19.8%, P<.001) were more frequently found in previous stroke patients than in nonstroke patients. Disturbance of electrolytes, including potassium and sodium, was more likely to occur in both previous- and new stroke patients. In terms of coagulation-related indexes, significantly increased D-dimer (80.5% and 84% vs 58.8%, P<.001, respectively) and fibrinogen (Fgb, 75.6% and 80.8% vs 60.6%, P=.005 and P=.001) were more prevalent in previous- and new stroke patients. Additionally, prolonged activated partial thromboplastin time (APTT, 47.7% vs 33.8%, P=.008), fibrinogen degradation products (FDP, 58.9% vs 32.6%, P<.001) and the incidences of decreased prothrombin activity (PTA, 1.1% vs 11.6%, P<.001) and thrombocytopenia (39.8% vs 19.4%, P<.001) were higher in previous stroke cases than in nonstroke cases.
Prognosis and survival analysis of COVID-19 patients with and without stroke
The stroke patients had a significantly worse outcome than patients in the nonstroke group (P<.001), including a higher mortality and longer disease course. Furthermore, the mean duration from symptom onset to the end point of observation was longer in the stroke group than in the nonstroke group (P<.05) (Table 1). However, the mean duration from admission to the end point of observation between the two groups was similar (Table 1). Kaplan–Meier survival curves showed an improved overall survival (OS) for patients without stroke compared to those with previous stroke and new stroke (all P<.001) (Figure 2). However, no significant difference was established regarding the OS between patients with previous stroke and those with new stroke (Figure 2).
Analysis of predictors for new stroke onset in COVID-19 patients
Data on clinical variables and log-rank regression analysis are listed in Table 3. As a result, age≥60 years, fingertip oxygen saturation (<93%) and consciousness disorder were independent predictors for new stroke occurrence in COVID-19 patients (P<.001). However, heart disease and diabetes were not independent predictors for new stroke occurrence under SARS-CoV-2 infection.