Clopidogrel Resistance Increases Rate of Recurrent Stroke and Other Vascular Events in Chinese Population

Abstract

Background: Research regarding clopidogrel resistance (CR) and ischemic stroke (IS) recurrence related to IS is scanty. The aim of the present study was to determine the incidence of CR and the association between CR and IS recurrence and other vascular events in patients with IS receiving clopidogrel.

Methods: CR was assessed by platelet aggregation assay in 535 IS patients receiving clopidogrel. All patients continued taking clopidogrel after discharge and were followed up for 6 months. The primary outcome was a composite of recurrent ischemic stroke (RIS), myocardial infarction, and death. The secondary outcome was the degree of disability as measured by modified Rankin Scale (mRS).

Results: Out of 535 IS patients, 208 (38.88%) were CR and 327 (61.12%) were clopidogrel sensitive (CS). Diabetes was independently associated with risk of CR (odds ratio: 2.42, 95% confidence interval [CI], 1.22-4.97, P <.01). During the follow-up period, the incidence of ischemic vascular events was higher in the CR group than in the CS group; the proportion of patients with mRS score of 0-2 points at 6 months was significantly lower in CR group than in CS group. CR (hazard ratio [HR]: 2.82, 95% CI, 1.23-6.94, P <.01), diabetes (HR: 1.61, 95% CI, 1.01-3.49, P = .02), and hypertension (HR: 1.84, 95% CI, 1.12-4.72, P = .03) were independent risk factors for ischemic vascular events.

Conclusion: The incidence of CR in IS patients taking clopidogrel is relatively high in the Chinese population. CR is associated with ischemic vascular events, including RIS, and poor neurological recovery.

Keywords: Ischemic stroke; clopidogrel resistance; prognosis; risk factors; stroke recurrence.