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S18 Abstracts Heart, Lung and Circulation2008;17S:S1–S209

38Infusion of Reconstituted HDL leads to Acute Changes inHuman Atherosclerotic Plaque In Vivo

James Shaw 2,∗, Alex Bobik 2, Peter Blombery 1, DmitriSviridov 2, Stuart Lyon 1, Anthony Dart 1

1 Alfred Hospital, Victoria, Australia; 2 Baker Heart ResearchInstitute, Victoria, Australia

Background: High-density lipoprotein (HDL) is an inversepredictor of cardiovascular events. Recent studies haveshown a reduction in plaque volume and change in plaqueultrasound characteristics after four infusions of reconsti-tuted HDL. Whether rHDL infusion leads to acute changesin plaque composition in humans is not known.Methods and results: Patients with symptom limiting clau-dication planned for percutaneous superficial femoralartery (sfa) revascularisation were randomised to eitherplacebo or IV r HDL infusion (80 mg/kg given over 4 h).5–7 days following the infusion patients returned andrevascularisation was performed including atherectomy(Foxhollow CA) to excise plaque from the sfa. 18 patients(15 male) average age 69 ± 10 years (mean ± S.D.) wererecruited. 10 had a history of documented coronary arterydisease and all patients were on aspirin and 16 on statins.9 of the patients received r HDL and 9 placebo. In the SFAplaque there was significantly less Vascular Cell AdhesionMolecule staining (23 ± 9 vs. 41.8 ± 3, p < 0.05) evidence of

eral arterial tonometry (RH-PAT) measures digital pulsevolume changes during reactive hyperaemia and is analternative assessment of endothelial function. Centralpulse wave velocity (PWV) is considered the best estimateof aortic stiffness.Method: Pressure waveforms were acquired in 20 healthymales (24 ± 5 years) from the carotid and femoral arteryand PWV calculated as the quotient of foot-to-foot pres-sure wave delay and distance. Salbutamol (an endothelialdependant agent) was given 25 min after GTN (anendothelial independent agent) was administered. Salbu-tamol:GTN index is the ratio of change in augmentationindex (AIx) with salbutamol relative to that with GTN. PeakRH-PAT ratio is the ratio of the peak digital pulse volumeduring reactive hyperemia divided by that at baseline.Results: Peak RH-PAT ratio was inversely associated withsystolic, diastolic and mean blood pressures (all p < 0.05,r2 = 0.25, r2 = 0.26, r2 = 0.23, respectively). Radial salbuta-mol:GTN index was related to peak RH-PAT ratio (p < 0.05,r2 = 0.245) and PWV (p < 0.001, r2 = 0.52). Carotid salbuta-mol:GTN index was not associated with the peak RH-PATratio or with PWV.Conclusion: In contrast to the radial pressure waveform,changes in carotid AIx do not reflect indices of endothelialfunction. This may be explained by the influence of arterialstiffness during pressure propagation.

oxygen free radicals (29 ± 23 vs. 100 ± 20, p < 0.05 (arbitraryunits)) and amount of lipid in the plaque as measured withOil red O staining in the HDL treated subjects comparedto placebo. The level of HDL-C increased by 20% afterinfusion of rHDL, but decreased after placebo infusion.The capacity of isolated HDL to support cholesterol effluxfrom cultured macrophages also increased after infusionof rHDL, but decreased after placebo infusions.Conclusion: Intravenous infusion of a single dose of recon-stituted HDL in subjects with peripheral vascular diseaseled to acute changes in plaque with a reduction in mea-sures of inflammation, oxidised free radicals and lipidcontent in subjects with peripheral vascular disease. Thesechanges may contribute to the presumed cardioprotectiveeffects of HDL.

doi:10.1016/j.hlc.2008.05.039

39Radial, but not Carotid, Salbutamol: GTN Index is relatedto Endothelial Function

Kevin Cheng, Sarah Hope ∗, Phillip Mottram, IanMeredith, James Cameron

Monash Cardiovascular Research Centre, Monash Heart,Southern Health & Department of Medicine (MMC), MonashUniversity, Melbourne, Victoria, Australia

Background: The central aortic pressure waveform isbelieved influenced by endothelial function and aorticstiffness. Pulse wave analysis of the radial artery com-bined with pharmacological challenge has been used toassess endothelial function. Reactive hyperaemia periph-

doi:10.1016/j.hlc.2008.05.040

40Digital Reactive Hyperaemia Response is related withCentral Pulse Wave Velocity

Kevin Cheng, Sarah Hope ∗, Phillip Mottram, IanMeredith, James Cameron

Monash Cardiovascular Research Centre, Monash Heart,Southern Health & Department of Medicine (MMC), MonashUniversity, Melbourne, Australia

Background: Reactive hyperaemia peripheral arterialtonometry (RH-PAT) is a new technique of assessingendothelial function by non-invasively measuring digi-tal pulse volume changes during reactive hyperaemia.Pulse wave velocity (PWV) has been shown to be directlyrelated to endothelial function as assessed by flow medi-ated dilatation. Relationships between PWV and digitalRH-PAT response have not been explored.Method: In 20 healthy male subjects (24 ± 5 years) pressurewaveforms were acquired by Millar Mikro-tip tonometryof the carotid and femoral arteries. PWV was calculated asthe quotient of the foot-to-foot pressure wave delay anddistance. Endothelial function is expressed as the peakRH-PAT ratio (ratio of the digital pulse volume duringreactive hyperemia divided by that at baseline). Analysiswas by regression and correlation techniques.Results: Central PWV was directly related to age (p < 0.001,r2 = 0.46). Peak RH-PAT ratio was inversely related toPWV (p < 0.05, r2 = 0.29), systolic (p < 0.05, r2 = 0.25), dias-tolic (p < 0.05, r2 = 0.26) and mean (p < 0.05, r2 = 0.23) bloodpressures. Carotid augmentation index and time to inflec-tion were not associated with peak RH-PAT ratio.