Frequency and significance of cardiac sources of embolism in the TOAST classification

Background: This study was aimed at determining the frequency and coexistent patterns of high- and medium-risk cardiac sources of embolism (CSE) as defined by the Trial of ORG 10172 in the Acute Stroke Treatment ( TOAST) classification system and at investigating how identified CSE contributed to this classification. Methods: We analyzed data from 2,482 patients with acute cerebral infarctions who registered in the Yonsei Stroke Registry over a 10-year period. Cardiac sources were divided into high- and medium-risk groups based on the TOAST classification. Results: Of the 2,482 patients, 1,130 (46%) underwent echocardiographic studies. At least one CSE was detected in 629 patients (25%). Atrial fibrillation was the most common high- risk CSE. Patent foramen ovale, spontaneous echo contrast and congestive heart failure comprised most of the medium-risk CSE. Atrial fibrillation frequently accompanied coexistent CSE (69%) such as spontaneous echo contrast, congestive heart failure, and left atrial/appendage thrombus, while patent foramen ovale was detected in isolation in more than 90% of the patients. Patients with a high- risk CSE were more likely to be diagnosed with cardioembolism (83%) than patients with only a medium-risk CSE (58%). Conclusions: Our study elucidated the frequency and various coexistent patterns of CSE in Korean stroke patients as defined by the TOAST classification system. In addition, we have demonstrated a higher correlation between high-risk CSE and cardioembolism than with medium-risk CSE and cardioembolism. Copyright (c) 2007 S. Karger AG, Basel.