Comparison Study of ASCO and TOAST Classification System in Chinese Minor Stroke Patients

Abstract

Background: Precise subtype classification based on underlying pathophysiology is important to prevent recurrent attack in minor stroke patients. A newly developed Atherosclerosis, Small vessel disease, Cardiac source, Others (ASCO) phenotypic classification system aims to characterize patients using different grades of evidence for stroke subtypes. However, this system has not been specifically applied to minor stroke population. In our study, the impact of using the newer ASCO criteria on minor stroke etiologies was investigated, and compared with that of Trial of ORG 10172 in Acute Stroke Treatment (TOAST) classification. Methods: Consecutive patients with minor ischemic stroke (NIHSS ≤3) were assessed and subtyped by the ASCO and TOAST systems. Stroke etiologies were presented and compared. The McNemar test and k statistic were used to analyze the difference and concordance between the 2 algorithms, respectively. Results: A total of 604 first-ever minor stroke patients were analyzed in the present study. Using TOAST classification, large artery atherosclerosis was the most frequent subtype (281, 46.5%), followed by small artery occlusion category (165, 27.3%). When ASCO was applied, 37 different profiles of stroke etiologies were identified. Using grade 1 of evidence, atherosclerosis (A1) was the most frequent subtype (308, 51.0%), followed by small vessel disease (S1, 178, 29.5%). Under consideration of grades 1 and 2, 239 (39.6%) patients were classified into more than 1 category. The ASCO system revealed determined etiologies in 104 of the 137 patients classified to cause undetermined subtype by TOAST classification. Good to very good accordance was observed between ASCO grade 1 and TOAST schemes across etiologic subtypes (κ = 0.719–0.832) except cause undetermined category (κ = 0.470). Conclusion: Application of ASCO decreased the proportion of patients assigned to cause undermined category compared to TOAST system. Comprehensive characteristics of ASCO system might be helpful in the personalized therapy or secondary prevention for individual patients in the future.

Prognosis and Associated Factors among Elderly Patients with Small Artery Occlusion

“…Small artery occlusion (SAO) is one of the ischemic stroke subtypes categorized by the Trial of ORG10172 in Acute Stroke Treatment (TOAST) 7 . Previous study reported that in developing countries, SAO accounting for 16–22% of ischemic stroke cases, the percentage higher 4% than developed countries; 8 however, the latest research showed that SAO accounts for 27.3% of ischemic stroke cases in China, higher than the world level 9 . It is crucial to identify the different potential underlying causes of stroke subtype to targeted treatment and decrease the burden of stroke in China.…”

Carotid Intraplaque-Hemorrhage Volume and Its Association with Cerebrovascular Events

“…The neurologic status at the time of CT was classified as symptomatic or asymptomatic according to the neurologic assessment documented in the clinical chart review using the Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria. 19,20 The maximum timing between events and imaging to consider a subject as symptomatic was 1 week. In the case of >1 week between ischemic symptoms and CTA of carotid arteries, the patient was excluded.…”

Cardiac CT for intra-cardiac thrombus detection in embolic stroke of undetermined source (ESUS)

“…The significant difference between intra-cardiac thrombi detection rates in these two cohorts may be attributed to the different prevalence of atherosclerosis, being the most common IS subtype in China. 26,27 LA/LAA thrombi detection: CCTA was shown to be an accurate and reliable alternative to TEE for the detection of LA/LAA thrombi in patients with AF, avoiding the discomfort and risks associated with TEE. 28 Compared to TEE as the gold standard for LA/LAA thrombi detection, mean sensitivity and specificity of CCTA are 96% and 92% respectively, and in some prospective single-center studies, have reached 100% and 99% respectively.…”

“…The significant difference between intra-cardiac thrombi detection rates in these two cohorts may be attributed to the different prevalence of atherosclerosis, being the most common IS subtype in China. 26,27…”