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J Res Med Sci 2022,  27:31

New-onset acute ischemic stroke following COVID-19: A case–control study

1 Department of Neurology, Al Zahra Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
2 Metabolic Liver Disease Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
3 Department of Orthopedic, Rothman Institute, Thomas Jefferson University, Philadelphia, Pennsylvania

Date of Submission13-Mar-2021
Date of Decision28-Oct-2021
Date of Acceptance10-Nov-2021
Date of Web Publication15-Apr-2022

Correspondence Address:
Dr. Mohammad Amin Najafi
Department of Neurology, Al Zahra Hospital, Sofeh Street, Isfahan
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jrms.jrms_255_21

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Background: Neurological manifestations of coronavirus disease 2019 (COVID-19) have been highlighted. COVID-19 potentially increases the risk of thromboembolism. We aimed to compare patients with COVID-19 with and without new-onset acute ischemic stroke (AIS). Materials and Methods: In this single-center retrospective casecontrol study, demographics, clinical characteristics, laboratory findings, and clinical outcomes were compared between 51 patients with both COVID-19 and AIS (group A) and 160 patients with COVID-19 and without AIS (group B). Results: Patients in group A were significantly older, more likely to present with critical COVID-19 (P = 0.004), had higher rates of admission in the intensive care unit (P < 0.001), more duration of hospitalization (P < 0.001), and higher in-hospital mortality (P < 0.001). At the time of hospitalization, O2 saturation (P = 0.011), PH (P = 0.04), and HCO3 (P = 0.005) were lower in group A. White blood cell count (P = 0.002), neutrophil count (P < 0.001), neutrophil-lymphocyte ratio (P = 0.001), D-Dimer (P < 0.001), blood urea nitrogen (BUN) (P < 0.001), and BUN/Cr ratio (P < 0.001) were significantly higher in patients with AIS. Conclusion: Stroke in COVID-19 is multifactorial. In addition to conventional risk factors of ischemic stroke (age and cardiovascular risk factors), we found that patients with more severe COVID-19 are more prone to ischemic stroke. Furthermore, leukocyte count, neutrophil count, neutrophil-lymphocyte ratio, D-Dimer, BUN, and BUN/Cr ratio were higher in patients with AIS following COVID-19 infection.

Keywords: Acute ischemic stroke, blood urea nitrogen, coronavirus disease 2019, D-dimer

How to cite this article:
Khorvash F, Najafi MA, Kheradmand M, Saadatnia M, Chegini R, Najafi F. New-onset acute ischemic stroke following COVID-19: A case–control study. J Res Med Sci 2022;27:31

How to cite this URL:
Khorvash F, Najafi MA, Kheradmand M, Saadatnia M, Chegini R, Najafi F. New-onset acute ischemic stroke following COVID-19: A case–control study. J Res Med Sci [serial online] 2022 [cited 2023 May 31];27:31. Available from: https://www.jmsjournal.net/text.asp?2022/27/1/31/343255

  Introduction Top

The coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a global concern and causes different clinical characteristics and complications; Neurologic manifestations have been highlighted in numerous studies.[1]

Previous studies reported that infectious agents increase the risk of ischemic stroke due to the prothrombotic effect of the inflammatory response, thus according to hypercoagulopathy state and the increase of thrombotic events in COVID-19 infection, the increased risk of stroke could be predicted.[2]

The literature is increasingly being focused on acute ischemic stroke (AIS) characteristics following COVID-19 infection.[3],[4],[5],[6] Studying the characteristics of stroke in patients with both COVID-19 and stroke may help to better understand the relation between these two diseases. The aim of this study is to compare clinical characteristics, laboratory data, and comorbidities between patients with COVID-19 with and without new-onset AIS.

  Materials and Methods Top

This was a single-center retrospective casecontrol study between October 22, and December 1, 2020. Fifty-one patients with confirmed COVID-19 and new-onset AIS were admitted to the Al Zahra Hospital (group A). One hundred and sixty-one confirmed COVID-19 patients, hospitalized in the same period in our center, were randomly selected as the control group (group B). Patients gave informed consent before take part in this trial. All patients tested positive for SARS-CoV-2 reverse transcription-polymerase chain reaction, had respiratory symptoms, had viral pneumonia findings on chest computed tomography (CT). AIS was diagnosed according to clinical symptoms and imaging studies (brain CT scan or Magnetic resonance imaging). The severity of the disease was determined according to the COVID-19 Treatment Guidelines Panel, which describes critical COVID as “patients with respiratory failure, multiple organ dysfunction, and septic shock.”

Demographic characteristics, patient's medical history, duration of hospitalization (ward or intensive care unit [ICU]), mortality rate, vital signs in admission, baseline laboratory findings, and pulmonary thromboembolism (PTE) rate were extracted from electronic medical records and compared between two groups.

Statistical analysis

Statistical analyses were carried out using the SPSS (SPSS statistic package, version 21.0.0, IBM SPSS Statistics for Windows, Version 21.0. Armonk, NY: IBM Corp.) statistical software. The Pearson Chi-square test and the t-test were used to determine whether there were any significant differences. The level of statistical significance was set at P < 0.05.

  Results Top

Fifty-one patients (24 males and 27 females) with both COVID-19 and new-onset AIS (group A) and 160 COVID-19 patients (86 male and 74 female) without new-onset AIS (group B) were surveyed. [Table 1] shows the comparison of the demographics and clinical characteristics between these groups. Group A patients were significantly older (73 ± 13 years vs. 66 ± 14 years, P < 0.001) and were more likely to present with critical COVID-19 (51% vs. 30%, P = 0.004). In-hospital mortality was significantly higher in group A (52.9% vs. 18.1%, P = 0.001). Group A were more likely to have other underlying disorders, including hypertension (HTN) (74.5% vs. 55%, P = 0.013), diabetes mellitus (DM) (54.9% vs. 36.2%, P = 0.017), previous stroke (21.5% vs. 5% P ≤ 0.001), ischemic heart disease (IHD) (39.2% vs. 20% P = 0.008), and atrial fibrillation (AF) rhythm (31.4% vs. 5% P ≤ 0.001). Group A was more likely to admit to the ICU (60% vs. 26.2% <0.001). The duration of hospitalization in both ward and ICU was greater in group A (15.7 ± 15.4 vs. 7.3 ± 4.8, P ≤ 0.001 and 11.4 ± 8.9 vs. 7.1 ± 5.2, P = 0.011, respectively). Group A showed significantly lower O2 saturation in the emergency room (82.4 ± 8.3 vs. 85.7 ± 7.8, P = 0.011). During hospitalization, pulmonary thromboendarterectomy (PTE) occurred in 6 (11.7%) patients in group A and 1 (0.6%) patient in group B (P < 0.001).
Table 1: Demographics and clinical characteristics of patients with coronavirus disease-2019 with or without new-onset acute ischemic strok

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[Table 2] summarized the laboratory findings in two groups. Patients in group A had higher white blood cell count (10323 ± 6093 vs. 7865 ± 4447 × 109/L, P = 0.002), higher neutrophil count (8788.2 ± 5759.2 vs. 6248.7 ± 3823.9; P < 0.001), lower lymphocyte percentage (11 ± 7% vs. 15 ± 10, P = 0.007), and higher neutrophil-lymphocyte ratio (NLR) (13.9 ± 17.2 vs. 8.03 ± 8.31, P = 0.001). Lymphocyte count, erythrocyte sedimentation rate, and C-reactive protein level showed no statistically significant differences between the two groups. Moreover, D-Dimer levels (2876 ± 2479 vs. 1344 ± 1196, P < 0.001), BUN, and BUN/Cr ratio were significantly higher in group A (P < 0.001). The analysis of venous blood gases variables in the emergency room revealed lower PH and HCO3 in group A (7.23 ± 0.42 vs. 7.30 ± 0.07, P = 0.040 and 19.33 ± 5.47 vs. 22.75 ± 7.92, P = 0.005, respectively). Serum level of albumin was significantly lower in AIS patients (3.31 ± 0.46 vs. 3.70 ± 0.45, P < 0.001).
Table 2: Laboratory findings of patients with coronavirus disease-2019 with or without new-onset acute ischemic stroke

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  Discussion Top

In agreement with previous literature, patients with AIS were older and more likely to die and have cardiovascular and cerebrovascular risk factors including HTN, DM, IHD, AF, and previous stroke.[4],[5],[7] The high prevalence of common vascular risk factors could be independently associated with the occurrence of stroke among patients with COVID-19 and play a significant role in the pathogenesis of this condition.

In brief, the binding of human angiotensin-converting enzyme 2 receptor and SARS-CoV-2 surface protein spike that cause endothelial apoptosis and neuronal damage mentioned as a probable association of COVID-19 severity and neurological symptoms.[8] Furthermore, hyperinflammatory state from cytokine storm followed by a prothrombotic state is frequently complicated by both venous and arterial thromboembolism.[9] Critical COVID and hypoxia in admit were more common in group A. Patients with critical illness were 2.5 fold more likely to be at risk of AIS. Bhatia et al. reported critical illness in 74% of patients with COVID and cerebrovascular disease (CVD).[3]

We showed higher leukocytosis and neutrophil count, lower lymphocyte percentage, and higher NLR in group A. Previous reports are almost the same, for example, Yao et al. compared 25 COVID-19 patients with new stroke and 2361 COVID-19 patients without stroke; they found that patients with stroke are more likely to have leukocytosis, neutrophilia, and lymphocytopenia and anemia.[6] Leukocytosis, lymphopenia, and high NLR are all inflammatory biomarkers that could be used as an indicator of systemic inflammation.[10] These blood parameters are independent predictors for the disease severity and survival of patients with COVID-19.[5],[10],[11]

D-dimer was significantly higher in group A. D-dimer is both a thrombus indicator and an acute phase reactant factor. D-dimer rise is basically due to a severe underlying COVID-19 infection.[12] Several studies have reported elevated levels of D-dimer in patients with COVID-19 and stroke.[13],[14],[15],[16] As mentioned elevated D-dimer levels in critically ill patients with COVID-19 could be the causes of abnormal blood coagulation function in the early stage and could render patients prone to acute CVD. Accordingly, AIS patients more tended to develop PTE during hospitalization.

As shown in previous studies, the presence of multiple organ dysfunction and over-activated systematic inflammation is more common in COVID-19 patients with stroke than in those without stroke.[13] In our study, the BUN and BUN/Cr ratios were higher in group A patients. Yao et al. reported higher levels of BUN and Cr in patients with AIS.[6] Another study showed higher levels of BUN and Cr among 11 patients with COVID and CVD in comparison to those without CVD.[13] An increased BUN level is a predictive factor of extrapulmonary organ injuries. Higher initial levels of BUN together with D-dimer are associated with mortality in COVID-19 patients and are used as an assessment tool for the prediction of mortality and severity in patients with COVID-19. Furthermore, it is mentioned in previous studies that BUN/Cr ratio is an independent predictor for COVID-19 severity and can help to identify high-risk cases.[10],[17]


First, it would be better to include more patients. Second, we did not measure other coagulation-and inflammatory-related indices, i.e., antiphospholipid antibodies, fibrinogen, interleukin-6, factor VIII, and Von Willebrand factor.

  Conclusion Top

Patients with AIS were older, had a more critical infection, more cardiovascular, and cerebrovascular risk factors (HTN, DM, IHD, AF, and previous stroke). Furthermore, we found that COVID-19 patients with higher leukocytosis, neutrophil count, NLR, D-Dimer, BUN, and BUN/Cr are more likely to develop stroke. These findings suggest that stroke in COVID-19 are probably multifactorial, and physicians should pay more attention to patients with critical infection, vascular risk factors, and those with higher mentioned laboratory markers.


This article has been approved by the ethics committee of the Isfahan University of Medical Sciences under the registration # IR. MUI. MED. REC.1400.300.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Leonardi M, Padovani A, McArthur JC. Neurological manifestations associated with COVID-19: A review and a call for action. J Neurol 2020;267:1573-6.  Back to cited text no. 1
Mehta P, McAuley DF, Brown M, Sanchez E, Tattersall RS, Manson JJ, et al. COVID-19: Consider cytokine storm syndromes and immunosuppression. Lancet 2020;395:1033-4.  Back to cited text no. 2
Bhatia R, Pedapati R, Komakula S, Srivastava MV, Vishnubhatla S, Khurana D. Stroke in coronavirus disease 2019: A systematic review. J Stroke 2020;22:324-35.  Back to cited text no. 3
Qureshi AI, Baskett WI, Huang W, Shyu D, Myers D, Raju M, et al. Acute ischemic stroke and COVID-19: An analysis of 27 676 patients. Stroke 2021;52:905-12.  Back to cited text no. 4
Tan YK, Goh C, Leow AS, Tambyah PA, Ang A, Yap ES, et al. COVID-19 and ischemic stroke: A systematic review and meta-summary of the literature. J Thromb Thrombolysis 2020;50:587-95.  Back to cited text no. 5
Yao X, Liu S, Wang J, Zhao K, Long X, He X, et al. The clinical characteristics and prognosis of COVID-19 patients with cerebral stroke: A retrospective cohort study. Eur J Neurosci. 2021 Feb;53(4):1350-1361. doi: 10.1111/ejn.15007. Epub 2020 Dec 21. PMID: 33052619; PMCID: PMC7675674.  Back to cited text no. 6
Arienti C, Brambilla L, Campagnini S, Fanciullacci C, Giunco F, Mannini A, et al. Mortality and characteristics of older people dying with COVID-19 in Lombardy nursing homes, Italy: An observational cohort study. J Res Med Sci 2021;26:40.  Back to cited text no. 7
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Jain A, Jafri F, Manglani R, Al-Mufti F, Aronow WS, Chandy D. Stroke in critical COVID-19 patients: A cautionary tale from the frontlines. Arch Med Sci Atheroscler Dis 2020;5:e263-70.  Back to cited text no. 8
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Katz JM, Libman RB, Wang JJ, Filippi CG, Sanelli P, Zlochower A, et al. COVID-19 severity and stroke: Correlation of imaging and laboratory markers. AJNR Am J Neuroradiol 2021;42:257-61.  Back to cited text no. 11
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  [Table 1], [Table 2]


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