The plasma concentration of high-density lipoprotein (HDL) can have anti-inflammatory, anti-oxidative and anti-thrombotic effects in addition to being able to remove cholesterol from peripheral tissues for secretion via the liver.

The investigators hypothesise that elevation of plasma HDLs will reduce the inflammatory response following removal of unstable atherosclerotic plaques in the carotid artery. Such plaques can cause strokes and there is great benefit from early surgical removal, however such surgical procedures involve significant risks to the patient.

The investigators propose infusing HDL into patients prior to removal of their unstable carotid plaque and measuring the changes in inflammatory responses in comparison to a similar placebo controlled group of patients.

Following written informed consent, patients will be randomised to either the placebo or active arm of the study. Bloods will be taken for baseline measurements, and the infusion of either saline (placebo) or rHDL (active agent) will be carried out on the ward. Infusion will take 4 hours, and the active agent infused at 40mg/kg.

Just prior to CAE, bloods will be collected (24 hours post-infusion) and the atherosclerotic tissue collected into RNA stabilising agent for subsequent analysis. Further bloods will then be collected 24 hours post-operatively (48 hours post-infusion).

Patients vital signs will be monitored hourly following infusion and will be reviewed in out-patients at 6 weeks after the operation.

Inclusion Criteria:

• patients listed for elective carotid endarterectomy

Exclusion Criteria:

• pregnant women and women of childbearing age
• patient with impaired renal function or liver function
• patients sectioned under the Mental Health Act