Open-Label Phase I Clinical Study to Assess the Safety and Efficacy of Cilostazol in Patients Undergoing Internal Carotid Artery Stent Placement

BACKGROUND: One-month dual antiplatelet treatment, with aspirin and clopidogrel, following internal carotid artery stent placement is the current standard of care to prevent in-stent thrombosis. Cilostazol, an antiplatelet drug, has been demonstrated to have a safety profile comparable to aspirin and clopidogrel. OBJECTIVE: To evaluate the safety and clinical efficacy of cilostazol and aspirin therapy following internal carotid artery stent placement up to 1 month postprocedure. METHODS: A phase I open-label, nonrandomized two-center prospective study was conducted. All subjects received aspirin (325 mg/day) and cilostazol (200 mg/day) 3 days before extracranial stent placement. Two antiplatelet agents were continued for 1 month postprocedure followed by aspirin daily monotherapy. The primary efficacy end point was the 30-day composite occurrence of death, cerebral infarction, transient ischemic attack, and in-stent thrombosis. The primary safety end point was bleeding. RESULTS: Twelve subjects (mean age ± SD, 66 ± 12 years; 9 males) were enrolled and underwent internal carotid artery angioplasty and stent placement. None of the subjects who successfully followed the study protocol experienced any complications at the 1- and 3-month follow-ups. One patient had a protocol deviation due to concurrent use of enoxaparin (1 mg/kg twice daily) in addition to aspirin and cilostazol, resulting in a fatal symptomatic intracerebral hemorrhage following successful stent placement on postprocedure day 1. One patient discontinued cilostazol after the first dose secondary to dizziness. CONCLUSION: The use of cilostazol and aspirin for internal carotid artery stent placement appears to be safe, but protocol compliance needs to be emphasized.