Etiologic Classification of TIA and Minor Stroke by A-S-C-O and Causative Classification System as Compared to TOAST Reduces the Proportion of Patients Categorized as Cause Undetermined

Abstract

Background: The assortment of patients based on the underlying pathophysiology is central to preventing recurrent stroke after a transient ischemic attack and minor stroke (TIA-MS). The causative classification of stroke (CCS) and the A-S-C-O (A for atherosclerosis, S for small vessel disease, C for Cardiac source, O for other cause) classification schemes have recently been developed. These systems have not been specifically applied to the TIA-MS population. We hypothesized that both CCS and A-S-C-O would increase the proportion of patients with a definitive etiologic mechanism for TIA-MS as compared with TOAST. Methods: Patients were analyzed from the CATCH study. A single-stroke physician assigned all patients to an etiologic subtype using published algorithms for TOAST, CCS and ASCO. We compared the proportions in the various categories for each classification scheme and then the association with stroke progression or recurrence was assessed. Results: TOAST, CCS and A-S-C-O classification schemes were applied in 469 TIA-MS patients. When compared to TOAST both CCS (58.0 vs. 65.3%; p < 0.0001) and ASCO grade 1 or 2 (37.5 vs. 65.3%; p < 0.0001) assigned fewer patients as cause undetermined. CCS had increased assignment of cardioembolism (+3.8%, p = 0.0001) as compared with TOAST. ASCO grade 1 or 2 had increased assignment of cardioembolism (+8.5%, p < 0.0001), large artery atherosclerosis (+14.9%, p < 0.0001) and small artery occlusion (+4.3%, p < 0.0001) as compared with TOAST. Compared with CCS, using ASCO resulted in a 20.5% absolute reduction in patients assigned to the ‘cause undetermined' category (p < 0.0001). Patients who had multiple high-risk etiologies either by CCS or ASCO classification or an ASCO undetermined classification had a higher chance of having a recurrent event. Conclusion: Both CCS and ASCO schemes reduce the proportion of TIA and minor stroke patients classified as ‘cause undetermined.' ASCO resulted in the fewest patients classified as cause undetermined. Stroke recurrence after TIA-MS is highest in patients with multiple high-risk etiologies or cryptogenic stroke classified by ASCO.

Phenotypic ASCO Characterisation of Young Patients with Ischemic Stroke in the Prospective Multicentre Observational sifap1 Study

“…Since the ASCO score was derived from CRF data only, this might have led to an underestimation of strokes caused by LAD in ASCO characterisation (with some cases scored as A9, despite a probable atherosclerotic stenosis or occlusion, due to missing information on the CRF). Being aware of these limitations, we chose to focus on the ASCO results rather than on the comparison to TOAST [11,12,23] . Finally, ASCO also permits documenting the quality of work-up for each aetiologic category.…”

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

“…The difference might relate to the high rate of MRI and MRA assessments in our study. For example, in Desai et al [10] investigation, CTA, but not MRA, was used for vascular evaluation; in the cohort of Marnane et al [11], brain MRI were conducted only in 50.1% of cases, and intracranial MRA in 29.4% of cases. Another investigation performed in Chinese ischemic stroke patients described similar etiologic distribution as that in our cohort using TOAST system [12], indicating that ethnic difference also contributed to the distribution of etiologies in ischemic stroke patients.…”

Патогенез Транзиторных Ишемических Атак: Проблема Подтипов

“…Проте розподіл ТІА за таким принципом в іноземних публікаціях згадується лише мимохідь [54][55][56] і практично не використовується в клінічній практиці лікарів-неврологів. У вітчизняній літературі також обґрунтовано не виділені підтипи ТІА, не висвітлені особливості клінічного перебігу та їх на-слідки залежно від провідного патогенетичного підтипу.…”