The Levels of Inflammatory Markers in the Treatment of Stroke study (LIMITS): inflammatory biomarkers as risk predictors after lacunar stroke

Abstract

Background: Inflammation is increasingly recognised as playing a central role in atherosclerosis, and peripheral blood markers of inflammation have been associated with incident and recurrent cardiac events. The relationship of these potentially modifiable risk markers to prognosis after ischaemic stroke is less clear. The Levels of Inflammatory Markers in the Treatment of Stroke (LIMITS) study will address hypotheses related to the role of inflammatory markers in secondary stroke prevention in an efficient manner using the well-established framework of the Secondary Prevention of Small Subcortical Strokes (SPS3) trial (NCT00059306).

Methods: SPS3 is an ongoing Phase III multicentre secondary prevention trial focused on preventing recurrent stroke in patients with small vessel ischaemic stroke, or lacunes. In SPS3, patients are assigned in a factorial design to aspirin vs. aspirin plus clopidogrel, and to usual vs. aggressive blood pressure targets. The purpose of LIMITS is to determine whether serum levels of inflammatory markers - including high-sensitivity C-reactive protein, serum amyloid A, CD40 ligand, and monocyte chemoattractant protein-1 - predict recurrent stroke and other vascular events among lacunar stroke patients. The project will also determine whether these markers predict which people will respond best to dual antiplatelet therapy with clopidogrel and aspirin, as well the relationship to cognitive function.

Analysis: plan Multivariable Cox proportional hazard regression modeling will be used to estimate hazard ratios for the effect of marker levels on risk of recurrent stroke and other outcomes after adjusting for additional potential risk factors, including age, gender, ethnicity, treatment arm, and traditional stroke risk factors. Interactions between marker levels and treatment assignment for both arms of the SPS3 study will be assessed. Observations will be censored at the time of last follow-up visit.

Conclusions: LIMITS represents an efficient approach to the identification of novel inflammatory biomarkers for use in risk prediction and treatment selection in patients with small vessel disease.

Figures

Figure 1

Plot of Power vs. Detectable Hazard Ratio for examining the effect of clopidogrel plus aspirin versus aspirin alone on inflammatory markers in stroke patients. (a) Solid line represents curve for endpoints or recurrent ischemic stroke (b) Dashed line represents curve for combined endpoint of ischemic stroke, MI, or death