Abstract TP128: Prognosis and Stratification of High-risk Patients with Mild (<50%), but Unstable Stenosis of Internal Carotid Artery - Multi-center Observational Study in Japan
Background and Purpose: Previous clinical trials have shown that clinical benefits of carotid endarterectomy (CEA) are unclear in symptomatic mild (<50%) stenosis of the internal carotid artery. However, it is not rare that the patients with mild carotid stenosis repeat TIA or ischemic stroke in spite of the best medical treatments. Although only the degree of stenosis have been accepted as “gold standard” in deciding treatment strategy, recent development of non-invasive MR imaging enables us to identify unstable plaque. Therefore, we have designed “Mild, but Unstable Stenosis of Internal Carotid artery (MUSIC) Study” in Japan. The objectives of this nation-wide, multicenter prospective study are to clarify the prognosis of patients with symptomatic mild carotid stenosis and identify the predictors for the patients at higher risk for recurrent TIA and ischemic stroke in spite of the best medical treatments. Impact of CEA is also evaluated in those refractory to the best medical treatments.
Methods and Results: MUSIC Study is conducted in Japan, using a multi-center prospective observational design (UMIN000023635). The MUSIC Study Group is composed of 28 hospitals. This study will register totally 250 patients who are 20 years or older, experience TIA, ischemic stroke, or retinal ischemia in the ipsilateral carotid territory, have mild (<50%) stenosis in the ipsilateral cervical carotid artery, and are independent in daily life (modified Rankin scale=0-2). Using MRI, plaque components are precisely evaluated in all patients. After informed consent is obtained, their clinical and radiological data are registered. They are followed up for two years and MRI/MRA examinations are repeated at 6, 12, and 24 months after the enrollment. Primary endpoint includes the incidence of ischemic stroke in the ipsilateral carotid territory. Secondary endpoints include the incidence of all-ischemic stroke, ipsilateral or all TIA, ipsilateral or all retina ischemia, all stroke, all death, de novo silent cerebral infarct, and progression of carotid stenosis.
Conclusion: In this conference, we emphasize the importance to identify the patients at higher risk for recurrent ischemic events due to symptomatic mild carotid stenosis in spite of the best medical treatments.
Author Disclosures: S. Kuroda: None. K. Ogasawara: None. M. Uno: None.
- © 2017 by American Heart Association, Inc.