Investigation of the stroke subtype of acute ischemic stroke patients admitted/referred to the emergency department

Objective: Stroke is a group of disease with high mortality and morbidity worldwide. Considering that most cases are in patients under the age of 70, stroke is not only a disease of the elderly. Since it causes loss of labor force and increased health expenditures, it is important to identify and prevent stroke risk factors and to determine the etiologic causes of stroke. In this study, we aimed to investigate the relationship between the etiologic subtypes of ischemic stroke and anterior and posterior system strokes, the relationship between the etiologic subtype and the affected vessels, and the effect of these relationships on mortality. Materials and Methods: In this study, demographic data, risk factors, stroke subtype and mortality rates of 403 patients who were admitted to the Emergency Department of Kirsehir Ahi Evran University Training and Research Hospital between 01/01/2019 and 31/12/2021 and diagnosed with acute ischemic stroke after intracerebral hemorrhage was ruled out by computed tomography and subsequently hospitalized in neurology service or intensive care unit were retrospectively analyzed. Results: The mean age of the patients included in our study was 72.35 ± 12.43 years and 50.4% were female. In our study, stroke risk factors, in order of frequency, were hypertension (HT) (80.9%), diabetes mellitus (DM) (43.7%), previous ischemic stroke (32. 3%), atrial fibrillation (AF) (32.0%), hyperlipidemia (HL) (31.5%), smoking (31.3%), coronary artery disease (CAD) (30.0%) and congestive heart failure (CHF) (13.4%). According to vascular territories, acute ischemic stroke was observed most frequently in middle cerebral artery (MCA) territory with a rate of 45.7% and mortality rate was most seen within 0-30 days with a rate of 20.59%. According to the Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification; our patient group was ranked as atherothrombotic stroke 50.6%, cardioembolic stroke 28.3%, lacunar stroke 12.4%, 'stroke of unknown cause' 7.2% and 'other causes of stroke' 1.5%. According to the Oxfordshire classification; 41.2% of our patients were in the partial anterior circulation infarction (most common), 28.5% in the posterior circulation infarction, 18.4% in the total anterior circulation infarction (TACI) and 11.9% in the lacunar cerebral infarction group. According to the TOAST classification; among the risk factors, HT was significantly higher in all stroke subtypes except 'other causes of stroke'; DM in atherothrombotic stroke and lacunar stroke; HL in lacunar stroke; CAD in 'stroke of unknown cause' group; CHF and AF in cardioembolic stroke; and smoking in 'other causes of stroke' group (p=0.000). In terms of diagnostic tests according to the same classification, the presence of AF (88.6%), low EF (<40%) (26.3%), mitral insufficiency (19.3%) and tricuspid insufficiency (16.7%) were found most frequently in the cardioembolic stroke group, while left ventricular hypertrophy (21.1%) and ipsilateral carotid stenosis of ≥70% (severe) (27.0%) were most common in the atherothrombotic stroke group (p=0.000). According to the Oxfordshire classification; among risk factors, the presence of HT (93.2%) and ipsilateral carotid stenosis of ≥70% (severe) in terms of diagnostic tests (50.0%) were found most frequently in the TACI stroke group (p<0.05). According to both classifications, survival rate was highest in the lacunar stroke group (p<0.05). Again, both classifications were consistent with each other in terms of etiology and vascular territory involvement (p=0.000). In further analysis, the mortality rate of MCA strokes was significantly higher than other vascular territories (p=0.000). There was no statistical difference between the mortality rates in right or left MCA total infarcts (p>0.05), whereas survival rates were higher in right and left MCA inferior division infarcts (p=0.000). When analyzed by gender, mortality rate was significantly higher in female patients compared to male patients in right MCA strokes (p=0.046). Conclusion: We found that most acute ischemic strokes occur in the MCA (left>right) territory, the mortality of MCA strokes is more frequent, the mortality is more pronounced in the female gender, especially in right MCA strokes, and the survival is longer in MCA inferior division occlusions. In this regard, we think that multicentered studies with large case series are needed. Keywords: Acute ischemic stroke, stroke classification, middle cerebral artery stroke, female, mortality