Clopidogrel Loading Dose Strategy in Acute Ischemic Mild to Moderate Strokes and High-risk Transient Ischemic Attacks: Evaluation of the 90-day Risk of Stroke Recurrence and Bleeding Events

BACKGROUND: There is no direct guidance on the optimal clopidogrel loading dose (LD) strategy when starting dual antiplatelet therapy (DAPT) in patients diagnosed with mild to moderate acute ischemic stroke (AIS) or high-risk transient ischemic attacks (TIA). OBJECTIVES: Determine whether a specific clopidogrel LD influences the rate of recurrent stroke or bleeding events in patients with high-risk TIA or mild-moderate acute ischemic stroke. METHODS: This is a multicenter, retrospective cohort study that included patients with mild-moderate AIS or high-risk TIA, treated with either a clopidogrel LD of 300 mg or 600 mg. The primary outcome was the incidence of recurrent ischemic stroke or TIA. The secondary outcomes assessed bleeding events, intracranial hemorrhage, myocardial infarction, mortality, and length of stay. RESULTS: Recurrent stroke (P = 0.16) occurred in 3% and 7% of the 300 mg and 600 mg groups, respectively. Recurrent TIA (P = 0.58) occurred in 1% and 3% of the 300 mg and 600 mg groups, respectively. Severe bleeding (P = 0.09) and moderate bleeding (P = 0.67) between the 300 mg and 600 mg LD groups were insignificant. CONCLUSION: This study represents the first evaluation of the effects of the clopidogrel LD on recurrent ischemic strokes and TIA. While the optimal duration of 21 days of DAPT therapy has been established and recommended in guidelines, the optimal loading dose has yet to be established. These results highlight the need for additional research to evaluate the true outcomes associated with the use of a 300 or 600 mg LD within this patient population.