22. European Stroke Conference 464 Small vessel stroke and white matter disease Blood Pressure Variability and Silent Small Vessel Cerebrovascular Lesions in Hypertensive Elderly Chinese B.J. XIE1, M.M. ZHANG2, H.K.F. MAK3, R.T.F. CHEUNG4 The University of Hong Kong, Hong Kong, HONG-KONG1, The University of Hong Kong, Hong Kong, HONG-KONG2, The University of Hong Kong, Hong Kong, HONG-KONG3, The University of Hong Kong, Hong Kong, HONG-KONG4 Background—Hypertension is the most important risk factor of small vessel cerebrovascular lesions (SVCL). Our study was considered to assess the association between blood pressure variability (BPV) and SVCL. Methods—139 healthy hypertensive Chinese aged 65-86 years were recruited from a general out-patient clinic. Previous blood pressure measurements up to three years were re-trieved from the medical record. BPV was indicated by the standard deviation (SD), coefficient of variation (CV), successive variation (SV) and variation independent of mean (VIM) blood pressure. Magnetic resonance imaging was performed to evaluate microbleeds (MB), brain infarcts (BI), periventricular hyperintensities (PVH) and deep white matter hyperintensities (DWMH). ANOVA and chi-square test were used to reveal any association between SCVL and BPV or other hyper-tension- related characteristics. Results—42 (30.2%) patients had MBs and 37 (26.6%) had BIs. 16 (11.5%) and 9 (6.5%) patients had severe PVH and DWMH (Fazekas Score=3), respectively. Both the severity of PVH and DWMH increased with age. All systolic BPV parameters were correlated with DWMH (P<0.05) but not PVH, MBs or BIs. Diastolic BPV parameters and other hyperten-sion- related characteristics were not associated with SVCL. Conclusion—Previous systolic BPV has a significant correlation with the severity of DWMH lesions. References: 1. Webb AJ, Fischer U, Rothwell PM. Effects of β-blocker selectivity on blood pressure variability and stroke: a system-atic review. Neurology 2011; 77: 731-7. 2. Rothwell PM. Limitations of the usual blood pressure hypothesis and importance of variability, instability, and episodic hypertension. Lancet 2010; 375: 938-48. 3. Liu W et al. Different impacts of blood pressure variability on the progression of cerebral microbleeds and white matter lesions. Stroke 2012; 43: 2916-22. 534 © 2013 S. Karger AG, Basel Scientific Programme Experimental studies (PO 465 - 485) 465 Experimental studies Thrombembolic stroke in mice: multicentric experimental phase 0 C. Orset1, B. Haelewyn2, D. Vivien3 INSERM - Université de Caen Basse Normandie, Caen, FRANCE1, Université de Caen Basse Normandie, Caen, FRANCE2, INSERM - Université de Caen Basse Normandie, Caen, FRANCE3 Current rodent models of stroke are useful both for studying the mechanisms of stroke and for estab-lishing the proof-of-concepts of new therapeutics. Unfortunately, all the successful therapies in pre-clinical studies failed in clinical trials. Recently, in a model of thromboembolic stroke in mice (Or-set et al. 2007), several studies, conducted in different labs, have demonstrated effects of the tissue plasminogen activator (tPA)-induced thrombolysis very similar to what reported in Human. Indeed, although tPA-induced thrombolysis is beneficial when injected early after stroke onset, it becomes deleterious when injected late after stroke onset. Here, we decided to perform a meta-analysis of these data providing an original multicentric study of the effects of a tPA-mediated thrombolysis in this model. Our analysis was restricted to saline treated animals, early tPA-treated animals and late tPA-treated animals. Inclusion criteria were also restricted to the data obtained from Swiss and C57B6 mouse strains, injected with 1 to 1.5 IU/μL of thrombin and tPA-induced thrombolysis (10 mg/kg) per-formed either 20 min or 4 hours post clot formation. Results showed a high reproducibility rate of the model independently of the experimenters. Both a beneficial effect of an early thrombolysis and a deleterious effect of a late thrombolysis were confirmed when looking at the lesion volumes. How-ever, a discrepancy was noted regarding the rate of hemorrhagic transformations between labs. This work is the first meta-analysis of a model of experimental stroke that could settle the bases for standardization of the experimental procedures needed for an experimental phase O for stroke as recommended by the STAIR criteria. This approach would help for better evaluation of stroke thera-pies to provide in the future an increased success rate for subsequent clinical trials.
Karger_ESC London_2013
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