Dual antiplatelet therapy reduced stroke risk in transient ischemic attack with positive diffusion weighted imaging

Abstract

Dual antiplatelet therapy (DAPT) reduced stroke risk in high-risk transient ischemic attack (TIA) patients assessed by ABCD2 score. Patients with positive diffusion-weighted imaging (DWI) were identified as imaging-based high-risk. The present study aims to investigate whether DAPT could reduce stroke risk in TIA with DWI positive. The study enrolled TIA patients within 72 h of onset from the prospective TIA database of the First Affiliated Hospital of Zhengzhou University. The predictive outcome was ischemic stroke at 90-day. The relationship between DAPT and stroke was analyzed in a cox proportional hazards model. The Kaplan-Meier curves of TIA patients with DAPT and monotherapy were plotted. Total of 661 TIA patients were enrolled, 279 of whom were DWI positive and 281 used DAPT. The 90-day stroke risk was higher in patients used monotherapy than those used DAPT in TIA with positive DWI (23.7% vs. 13.4%, p = 0.029). DAPT was associated with reduced stroke risk in TIA patients with positive DWI (hazard ratio [HR] = 0.54; 95% confidence interval [CI], 0.30-0.97; p = 0.037). However, the benefit didn't exist in TIA patients with negative DWI (HR = 0.43; 95% CI, 0.14-1.33; p = 0.142). Early use of DAPT reduced stroke risk in TIA patients with positive DWI.

Figure 1

Flow diagram of the eligible TIA patients. A total of 827TIA patients within 72 h of onset were prospectively enrolled from October 2010 to June 2015. Excluded were 46 with unavailable DWI information, 59 with endovascular therapy or surgery, 46 without antiplatelet therapy, 15 patients lost-to follow-up at 90 days. In patients with DWI positive, 127 patients (45.5%) used DAPT therapy. And in patients with DWI negative, 154(40.3%) patients used DAPT therapy.

Figure 2

Cumulative probability of ischemic stroke in TIA patients with monotherapy and DAPT by DWI patterns. In TIA patients with DWI positive, there was a significant difference in the 90-day stroke rate between DAPT and monotherapy (log-rank test = 4.994, p = 0.025, A). However, the difference was not statistical significance in patients with DWI negative (log-rank test = 2.106, p = 0.147, B).