London, United Kingdom 2013 12 Vascular biology Downstream Microvessel Calibre Changes Following Carotid Artery Ligation in a Rodent Model D.A. De Silva1, K.T. Moe2, P Liao3, L.P. Talabucon4, K.P. Loh5, F.P. Woon6, T.Y. Wong7, A.B. Ve-luchamy8, M.C. Wong9, 10, 11, 12, 13, 14, 15 National Neuroscience Institute, Singapore, SINGAPORE1, National Heart Centre, Singapore, SINGAPORE2, National Neuroscience Institute, Singapore, SINGAPORE3, National Neuroscience Institute, Singapore, SINGAPORE4, National Neuroscience Institute, Singapore, SINGAPORE5, Singapore General Hospital, Singapore, SINGAPORE6, Singapore Eye Research Institute, Singa-pore, SINGAPORE7, Singapore Eye Research Institute, Singapore, SINGAPORE8, National Univer-sity of Singapore, Singapore, SINGAPORE9 Background: Carotid artery obstruction is known to cause cerebral and retinal ischemia. With their similar arterial supply, venous drainage and calibre, retinal microvasculature changes are postu-lated to mirror those in cerebral microvessels. Our group previously showed that carotid ligation was associated with increase in ipsilateral retinal arteriolar calibre by day 5. Methods: We serially studied early retinal microvascular changes in the hours and days following carotid ligation to un-derstand the onset and progression of these downstream changes. Male Wistar rats underwent left common carotid artery ligation (n=12) or sham surgery (n=11). Retinal photographs were assessed with semi-automated methods by blinded graders. Results: Retinal arteriolar calibre of the ipsilateral and contralateral eyes increased within 20 minutes in the occlusion arm (ipsilateral 30.35 μm IQR 28.61-32.32 vs 35.72 μm IQR 33.52-38.51, p=0.003; contralateral 30.03 μm IQR 28.17-32.13 vs 32.05 μm IQR 27.42-34.30, p=0.155) and sham arm (ipsilateral 30.56 μm IQR 29.79-31.10 vs 37.62 μm IQR 32.97-40.64, p=0.006; contralateral 32.02 μm IQR 29.73-34.18 vs 34.93 μm IQR 30.26- 38.95, p=0.026). This arteriolar calibre increase returned to baseline levels by 3 hours in all but the ipsilateral eye of the occlusion arm. There was a second increase in arteriolar calibre in the ipsilater-al eye of the occlusion arm observed between 6 hours and 1 day from surgery (34.83 μm IQR 32.03- 37.80 vs 39.21 μm IQR 38.09-43.14, p=0.003) which persisted until the end of the experiment at day 14. Following carotid occlusion, there was an initial downstream ipsilateral retinal arteriolar calibre increase within 20 minutes followed by a further increase after 6 hours which persisted up to 14 days. Conclusion: These observations provide insights of likely initial smooth muscle relaxation with vasodilatation and subsequent vascular remodelling due to physical structural wall changes in downstream arterioles in response to proximal large artery acute obstruction. E-Poster Session Red Cerebrovasc Dis 2013; 35 (suppl 3)1-854 253 11 Vascular biology CIRCULATING ENDOTHELIAL PROGENITOR CELLS PREDICT THE OCCUR-RENCE OF CARDIOVASCULAR EVENTS IN PATIENTS WITH ATHEROTHROMBOTIC STROKE. PROCELL STUDY. E. Cuadrado-Godia1, E. Giralt-Steinhauer2, M. Díaz-Ricart3, G. Escolar4, J. Sanchis5, A. Regue-iro6, M. Heras7, S. Novella8, C. Hermenegildo9, R. Elosua10, A. Oliveras11, J. Roquer12 Neurology Department. Hospital del Mar. Institut Hospital del Mar d’Investigación Médica (IMIM), Barcelona, SPAIN1, Neurology Department. Hospital del Mar. Institut Hospital del Mar d’Investigación Médica (IMIM), Barcelona, SPAIN2, Hemotherapy and Hemostasis Department. Hospital Clínic. Instituto de Investigaciones Biomédicas August Pi i Sunyer Barcelona, Spain, Barcelona, SPAIN3, Hemotherapy and Hemostasis Department. Hospital Clínic. Instituto de Inves-tigaciones Biomédicas August Pi i Sunyer, Barcelona, SPAIN4, Cardiology Department. Hospital Clínico Universitario de Valencia, Valencia, SPAIN5, Cardiology Department. Hospital Clínic i Provincial. Instituto de Investigaciones Biomédicas August Pi i Sunyer, Barcelona, SPAIN6, Cardi-ology Department. Hospital Clínic i Provincial. Instituto de Investigaciones Biomédicas August Pi i Sunyer, Barcelona, SPAIN7, Fundación de Investigación. Hospital Clínico Universitario de Valen-cia., Valencia, SPAIN8, Fundación de Investigación. Hospital Clínico Universitario de Valencia., Va-lencia, SPAIN9, Cardiovascular Epidemiology and Genetics. Institut Hospital del Mar d’Investigación Médica (IMIM), Barcelona, SPAIN10, Department of Nephrology. Hypertension Unit. Hospital del Mar. Institut Hospital del Mar d’Investigación Médica (IMIM)., Barcelona, SPAIN11, Neurology De-partment. Hospital del Mar. Institut Hospital del Mar d’Investigación Médica (IMIM, Barcelona, SPAIN12 BACKGROUND : Circulating endothelial progenitor cells (EPCs) have been implicated in neoan-giogenesis after tissue ischemia. Low EPCs have been associated with higher risk of major cardiac events in patients with coronary artery disease but this association has not been previously reported in stroke patients. PROCELL study aimed to analyse the prognostic role of EPCs in both patients with ischemic stroke of atherothrombotic origin (IAS) and patients with acute myocardial infarction (AMI) METHODS: 100 patients with AMI and 50 patients with IAS were prospectively included. Ath-erosclerotic burden was calculated according to the affected vascular territories (cerebral, coronary, peripheral) either clinically or in the screening tests. Blood was withdrawn within the first 24h and at 7, 30, 90 and 180 days. Number of EPCs (CD45-, CD 34+, KDR+) was analyzed by flow cytom-etry. Patients were followed up 6 months. The association between baseline levels of EPCs and the occurrence of a new vascular event (NVE) including AMI, stroke, hospitalization or death from car-diovascular causes was evaluated by Cox regression analysis. EPCs were analysed in quartiles. RESULTS: EPCs levels increased during the first month in AMI and stroke patients (p=0.002). AMI patients showed higher basal levels of EPCs than IAS patients 201(66.3-420) vs 90 (29- 170), p<0.001 and higher levels during the study period. Seventeen patients (11.3%) had a NVE (8 stroke, 3 AMI, 5 hospitalizations, 1 vascular death). NVE were associated with age (p=0.014), atherosclerotic burden (p=0.032) and a lower number of basal EPCs (p=0.020). After adjustment for these variables, increased number of basal EPCs was associated with lower risk of NVE (HR: 0.078 for each quartile, 95% CI: 0.011-0.5, p=0.011) in IAS patients but not in AMI patients. CONCLUSIONS: Circulating EPC levels within the first 24h after AIS predicted the occurrence of NVE and might help to identify patients with high cardiovascular risk.
Karger_ESC London_2013
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