The goals of this trial are to determine the prognostic significance of an elevated level of inflammatory blood markers in people who have experienced small subcortical strokes and who are enrolled in the Secondary Prevention of Small Subcortical Strokes (SPS3) trial.

Inflammation is increasingly recognized as playing a central role in atherosclerosis and coronary artery disease. And, peripheral blood markers of inflammation have been associated with incident and recurrent cardiac events. The relationship of these risk markers-which have the potential to be modified-to prognosis after ischemic stroke is less clear.

The Levels of Inflammatory Markers in the Treatment of Stroke (LIMITS) study will address questions about the role of inflammatory markers in secondary stroke prevention in a cost-effective manner using the well-established framework of the Secondary Prevention of Small Subcortical Strokes (SPS3) trial. The SPS3 trial is an ongoing Phase 3, multicenter secondary stroke prevention trial that focuses on preventing stroke recurrence in people with small vessel ischemic stroke, or lacunes.

The overall purpose of the LIMITS study is to determine if serum levels of inflammatory markers-such as hsCRP, serum amyloid A (SAA), CD40 ligand (CD40L), and monocyte chemoattractant protein-1 (MCP-1)-predict recurrent stroke and other vascular events among people with a history of small artery ischemic stroke. The project will also determine if these markers predict which people will respond best to dual antiplatelet therapy with clopidogrel and aspirin.

The specific aims of LIMITS are to determine if hsCRP, SAA, CD40L, and MCP-1 levels are independent risk factors for recurrent ischemic stroke, and for recurrent ischemic stroke, myocardial infarction, and death in participants in the SPS3 trial after adjusting for demographic and traditional stroke risk factors, and other treatments, using a prospective cohort of people with small subcortical strokes from the SPS3 trial. LIMITS also aims to compare the efficacy of dual versus single antiplatelet therapy among participant groups with and without elevated baseline inflammatory marker levels for the outcome of a.) recurrent stroke, and b.) recurrent ischemic stroke, myocardial infarction, or death.

Inclusion Criteria:

• Patient must be randomized within 6 months of qualifying small subcortical stroke (S3) or subcortical TIA
• One of the following lacunar syndromes: PMH; pure sensory stroke; sensorimotor stroke; ataxic hemiparesis; dysarthria; hemiballism; PMH with facial sparing, horizontal gaze palsy, contralateral III palsy, contralateral VI palsy; Ataxia with contralateral III palsy; pure dysarthria
• Absence of cortical dysfunction (aphasia, apraxia, agnosia)
• No ipsilateral cervical carotid stenosis (>= 50%) if S3 is hemispheric
• No major-risk cardioembolic sources requiring anti-coagulation
• MRI evidence of S3 that is >=2.0 cm in diameter if DWI/bright lesion on FLAIR/T2 or <=1.5cm hypointense lesion on FLAIR/T1, corresponding to the qualifying event (required for all brainstem events) OR multiple S3 in cerebral hemispheres of <=1.5cm hypointense lesions on FLAIR/T1 AND absence of cortical stroke and large subcortical stroke.

Exclusion Criteria:

• Disabling stroke (Ranking Scale >= 4)
• Prior hemorrhagic stroke
• Age <30 years
• High risk of bleeding (recurrent GI or GU bleeding, active peptic ulcer disease, etc)
• Need for long-term use of anticoagulants or other antiplatelet agents.
• Prior cortical or retinal stroke / TIA
• Prior ipsilateral carotid endarterectomy if hemispheric S3
• Impaired renal function: GFR<40 cc/min
• Intolerance/contraindication to aspirin or clopidogrel
• Adjusted Folstein MMSE <24
• Medical contraindication to MRI
• Pregnancy or child-bearing potential without contraception
• Other specific causes of stroke (e.g. dissection, vasculitis, drug abuse)

Patients with a symptomatic small vessel stroke within prior 6 month and enrolled in SPS3