W03-O-001 Increased numbers of circulating endothelial cells predict adverse cardiovascular events following an acute coronary syndrome

12

Workshops W3 Emtothelial control ofhypercoagulability

for venous thrombosis with conflicting results. Thrombomodulin gene, which encodes a receptor supporting the antithrombogenic properties of the endothelium through activation of PC, bears several polymorphisms, which could regulate its expression. The first heterozygous mutation causing loss of function was described associated with pulmonary embolism, cerebral venous sinus thrombosis and stroke. Evidence that impaired function of these endothelial proteins causes disease derives from animal models. In mice a complete loss of thrombomodulin or EPCR function is incompatible with embryonic development. No natural molecular lesion is yet available for PAR and the hemostatic effects of knock out mouse models point toward loss of platelet activation. The apparently very low prevalence of deleterious mutations in genes of these receptors might be explained by selection in utero and/or by the lack of assays able to screen patients for functional deficiencies, which would favour detection of heterozygous lesions in humans.

I W03-O-001 ] INCREASED NUMBERS OF CIRCULATING ENDOTHELIAL CELLS PREDICT ADVERSE CARDIOVASCULR EVENTS FOLLOWING AN ACUTE CORONARY SYNDROME A.D. Blann, K. Lee, G.Y.H. Lip. University Department of Medicbw, City

Hospital, Birmingham, UK Background: Markers of endothelial perturbation (e.g. von Willebrand factor [vWf] and circulating endothelial cells [CECs]) are altered in acute coronary syndromes (ACS). Raised vWf predicts major cardiovascular thrombotic endpoints (MACE) but it is unclear whether or not raised numbers of CECs are also predictive, or are superior to vWf. We hypothesised that CECs and vWf levels during the first 48hrs of ACS would predict MACEs at 30day and 1 year. Methods: 156 patients with ACS were included. Blood was drawn on admission (baseline) and 48hrs later for plasma vWf (ELISA) and CECs (CD 146 immunomagnetic separation). Results: At 30days, 48 patients had >1 MACE, predicted by baseline and 48hr CECs, 48hr vWf levels, and by the 'admission-48hr change'(A) in CECs and vWf (all p <0.002). On multivariate analysis, 48hr CECs (p<0.001) were the strongest predictor of MACE, followed by AvWf (p=0.048); 48hr CECs were the only predictor of death (p=0.007). At 1 year, 65 patients had >1 MACE, predicted by 48hr CECs (p<0.001). Age (p=0.046) and 48hr CECs (p<0.001) were the only predictors of death. CECs >6 cells/mL (median of the entire group) on admission correctly identified 97.5% of 30day MACEs, 90% of 1 year MACEs, 100% of 30day deaths and 93.3% of 1 year deaths Conclusions: Admission, 48 hour, and the acute rise in vWf and CECs all generally predicted adverse thrombotic outcome. However, admission CECs were the best overall predictors of MACE and death at 30d and after a year, indicating the crucial role of endothelial/vascular damage in ACS pathophysiology.

I W03-O-002 ] DIETARY SUPPLEMENTATION WITH OILY FISH REDUCES PLATELET-MONOCYTE AGGREGATION IN MAN J.N. Din, S.A. Harding, C.J. Valerio, J. Sarma, D.E. Newby, A.D. Flapan.

Department of Cardiology, Royal Infirmary of Edinburgh, Edinburgh, UK Objective: High dietary intake of oily fish is associated with a reduction in cardiovascular events. The mechanisms for this are uncertain. Plateletleukocyte aggregates (PMA) are sensitive markers of platelet activation and may contribute to the initiation and progression of atherothrombosis. This study assessed the effect of dietary supplementation with oily fish on PMA. Methods: Fourteen healthy male volunteers had their diet supplemented with 500g smoked mackerel a week (equivalent to 1.5g of EPA+DHA per day) for 4 weeks. A control group of 14 healthy males received no dietary intervention over a 4 week period. Peripheral venous blood sampling and dietary assessment using a 3-day weighed food diary was performed before and after dietary supplementation with oily fish as well as 4 weeks following cessation of fish supplementation. PMA was assessed by 2-colour flow cytometry. Results: There was a large increase in n-3 polyunsaturated fatty acid (PUFA) intake during to the period of supplementation (0.184-0.17 g/day vs. 1.804-0.28 g/day, p<0.001). Intake of n-3 PUFA was similar prior to and following cessation of fish supplementation (0.184-0.17 g/day vs. 0.42 4-0.53 g/day, p=ns). PMA was reduced by 35% following dietary

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supplementation with oily fish (24.84-2.9% vs. 16.04-2.4%, p<0.01). PMA had returned to previous levels four weeks after discontinuation of supplementation (24.84-2.9% vs. 23.64-2.9%, p=ns). There was no significant change in PMA over 4 weeks in the control group (21.5-t-1.8% vs. 18.7-t-1.8%, p=ns). Conclusion: Dietary supplementation with fish rich in n-3 polyunsaturated fatty acids reduces PMA, an effect that is fully reversed 4 weeks following cessation of supplementation. This may represent an important and previously unreported mechanism by which intake of oily fish reduces cardiovascular events.

IW03-O-003

I

Ii EFFECT OF FOLIC ACID AND VITAMIN B12 ON

ENDOTHELIAL FUNCTION, OXIDATIVE STRESS AND P R O T H R O M B O T I C FACTORS A F T E R RENAL TRANSPLANTATION

J.A. Rodriguez 1, J. Manrique 2, A. Diaz 3, J.J. Gavira 3, J. Orbe 1, P. Errasti 2, J.A. Paramo I . 1Atherosclerosis Research Laboratory, Div. of

Cardiovascular Pathophysiology, FIMA, Pamplona; 2 Dept. of Nephrology, University Clinic, University of Navarra, Pamplona; 3Dept. of Cardiology, University Clinic, University of Navarra, Pamplona, Spain. Objective: Renal transplant recipients (RTRs) present higher risk of atherothrombosis and frequently show increased plasma homocysteine (Hcys). This study aims to study vascular risk markers in hyperhomocysteinemic RTRs, and test whether reduction of Hcys by folate and B12 supplementation can modify these markers. Methods: 70 RTRs were classified, based on their total plasma Hcys, as normal (Hcys< 14 ItM, n=14, G1) or hyperhomocysteinemic (Hcys > 14 ttM, n=56), which were randomized to receive folate and B12 (G2, n=28) or not (G3, n=28) for 3 months. Lipid profile, albumin, creatinine, C reactive protein (hs-CRP), von Willebrand factor (vWF), fibrinogen and hemoglobin were determined in plasma. 8-OHdG, 8-iso-prostaglandin F2 and creatinine were measured in urine. Ultrasound-derived arterial endothelial function (endothelium-dependent dilation) of the brachial artery was also evaluated. Results: Hyperhomocysteinemic RTRs, showing worse renal function, exhibited decreased endothelial function (p<0.05), increased CRP (p<0.05), 8-OHdG (p<0.05), fibrinogen (p<0.05) and vWF (p<0.05). Folate and B12 treatment reduced Hcys plasma levels (p<0.05), CRP (p~0.05), 8-OHdG (p<0.05), fibrinogen (p<0.05) and vWF (p<0.05). Endothelial function was significantly improved in G2 group (p<0.05). Conclusions: Hyperhomocysteinemia in RTRs is associated with endothelial dysfunction, increased oxidative stress, inflammation and prothrombotic risk. These cardiovascular risk factors can be improved by reducing plasma Hcys through folate and B12 supplementation, suggesting a beneficial role in kidney graft recipients.

I WO3-P-O01 I INCREASED CIRCULATING ENDOTHELIAL CELLS IN ACUTE CONGESTIVE H E A R T FAILURE: C O M P A R I S O N A.D. Blann, A.Y. Chong, B. Freestone, G.Y.H. Lip. University Department

of Medicine, City Hospital, Birmingham, UK Background: Circulating endothelial cells (CECs) in the peripheral blood, probably representing the most direct evidence of endothelial cell damage, are increased in myocardial infarction, unstable angina and critical limb ischaemia. As chronic congestive heart failure (CHF) is also associated with endothelial abnormalities, we hypothesised that CECs are raised in

75th EAS Congress, 23-26 April 2005, Prague, Czech Republic