INTRODUCTION Carotid atherosclerotic intraplaque hemorrhage (IPH) predicts stroke. Patients with a history of stroke are treated with antiplatelet agents to prevent secondary cardiovascular events. A positive association between previous antiplatelet use and IPH was reported in a cross-sectional analysis. We investigated changes in IPH over two years in patients who recently started versus those with continued antiplatelet use. METHODS In the Plaque at Risk (PARISK) study, symptomatic patients with <70% ipsilateral carotid stenosis underwent carotid plaque MRI at baseline and after two years to determine IPH presence and volume. Participants were categorized into new users (starting antiplatelet therapy following the index event) and continued users (previous use of antiplatelet therapy before the index event). The association between previous antiplatelet therapy and the presence of IPH at baseline MRI was investigated using multivariable logistic regression analysis. IPH volume change over a period of two years, defined as the difference in volume between follow-up and baseline, was investigated in each group with a Wilcoxon signed-rank test. The IPH volume change was categorized as progression, regression, or no change. Using multivariable logistic regression, we investigated the association between new antiplatelet use and 1) newly developed ipsilateral or contralateral IPH and 2) IPH volume progression. RESULTS A total of 108 patients underwent carotid MRI at baseline and follow-up. At baseline, previous antiplatelet therapy was associated with any IPH (OR=5.6, 95% CI: 1.3-23.1; p=0.02). Ipsilateral IPH volume did not change significantly during the two years in patients who continued receiving antiplatelet agents (86.4 mm3 [18.2-235.9] vs. 59.3 mm3 [11.4-260.3]; p=0.6) nor in the new antiplatelet users (n=31) (61.5 mm3 [0.0-166.9] vs. 27.7 mm3 [9.5-106.4]; p=0.4). Similar results of a nonsignificant change in contralateral IPH volume during those two years were observed in both groups (p>0.05). No significant associations were found between new antiplatelet use and newly developed IPH at two years (odds ratio (OR)=1.0, 95% CI:0.1-7.4) or the progression of IPH (ipsilateral: OR=2.4, 95% CI:0.3-19.1; contralateral: OR=0.3, 95% CI:0.01-8.5). CONCLUSION Although the baseline association between IPH and previous antiplatelet therapy was confirmed in this larger cohort, the new onset of antiplatelet therapy after TIA/stroke was not associated with newly developed IPH or progression of IPH volume over the subsequent two years.

中文翻译：

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抗血小板治疗与轻度至中度症状性颈动脉狭窄患者斑块内出血变化之间的关联：一项纵向 MRI 研究。

简介 颈动脉粥样硬化斑块内出血 (IPH) 可预测中风。有中风病史的患者接受抗血小板药物治疗，以预防继发性心血管事件。一项横断面分析报告称，既往使用抗血小板药物与 IPH 之间存在正相关关系。我们调查了最近开始使用抗血小板药物的患者与持续使用抗血小板药物的患者在两年内的 IPH 变化。方法 在危险斑块 (PARISK) 研究中，同侧颈动脉狭窄 <70% 的有症状患者在基线和两年后接受颈动脉斑块 MRI 以确定 IPH 的存在和体积。参与者被分为新用户（在指标事件后开始抗血小板治疗）和持续用户（在指标事件前曾使用过抗血小板治疗）。使用多变量逻辑回归分析研究既往抗血小板治疗与基线 MRI 中 IPH 存在之间的关联。两年期间的 IPH 体积变化（定义为随访与基线之间的体积差异）通过 Wilcoxon 符号秩检验对每组进行了调查。IPH 体积变化分为进展、消退或无变化。使用多变量逻辑回归，我们研究了新的抗血小板药物使用与 1) 新发生的同侧或对侧 IPH 和 2) IPH 体积进展之间的关联。结果 共有 108 名患者在基线和随访时接受了颈动脉 MRI 检查。基线时，既往抗血小板治疗与任何 IPH 相关（OR=5.6，95% CI：1.3-23.1；p=0.02）。在继续接受抗血小板药物的患者（86.4 mm3 [18.2-235.9] vs. 59.3 mm3 [11.4-260.3]；p=0.6）和新的抗血小板药物使用者（n=31）中，同侧 IPH 体积在两年内没有显着变化）（61.5 mm3 [0.0-166.9] 对比 27.7 mm3 [9.5-106.4]；p=0.4）。在这两年中，两组中均观察到对侧 IPH 体积无显着变化的类似结果 (p>0.05)。新使用抗血小板药物与两年内新发生 IPH（比值比 (OR)=1.0，95% CI：0.1-7.4）或 IPH 进展（同侧：OR=2.4，95% CI：0.3）之间没有发现显着关联-19.1；对侧：OR=0.3，95% CI：0.01-8.5）。结论 虽然在这个较大的队列中证实了 IPH 与既往抗血小板治疗之间的基线相关性，但 TIA/卒中后新开始的抗血小板治疗与新发生的 IPH 或随后两年 IPH 体积的进展无关。