Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz
Gewählte Publikation:
Tschmelak, D.
Coagulation Changes during Orthostatic Challenge in Older Persons: Effects of Gender and Stroke
Humanmedizin; [ Diplomarbeit ] Graz Medical University; 2017. pp.
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- Autor*innen der Med Uni Graz:
- Betreuer*innen:
- Goswami Nandu
- Altmetrics:
- Abstract:
- Introduction: The purpose of this study was to investigate the hemostatic changes during orthostatic challenge in old people with a history of stroke compared to an age-matched healthy control group. Methods: Forty-four subjects were recruited for this pilot study. Twenty-two had a history of ischemic stroke and the remaining twenty-two were classified in the healthy control group. All subjects performed a sit-to-stand test for 6 minutes and blood samples were taken before and after the stand test. We measured haematocrit, plasma levels of coagulation factors, copeptin to investigate changes on the hormonal level, standard coagulation times, and markers of endothelial activation such as tissue-plasminogen activator and tissue factor. Furthermore we performed a thrombelastometry and did a calibrated automated thrombogram test and determined thrombin generation values such as prothrombin fragment 1+2 and thrombin/antithrombin complex. Results: Orthostatic challenge is associated with coagulation and endothelial activation in both groups the patients as well as the healthy control group. In both groups Prothrombin time was shorter in post-standing samples, prothrombin fragments 1+2 were significantly higher and thrombin/antithrombin complex decreased. Patients who have recovered from stroke are more sensitive to coagulation changes during orthostatic stress than healthy people. Many coagulation values changed only in patients with history of stroke during orthostatic stress: Tissue factor increased (from 338 pg/ml to 481 pg/ml), as well as Copeptin (from 501 pg/ml to 627 pg/ml), the peak rate of thrombin generation (VELINDEX, from 8 nM/min to 10 nM/min) and the alpha angle (from 56° to 60°). The Coagulation time from the Thrombelastometry was significantly shorter (from 319s to 284s) in post standing samples. Tissue-plasminogen activator was significantly higher only in the healthy control group. Conclusion: Patients with a history of ischemic stroke have a higher risk for a shift towards a hypercoagulation state and also fail to activate the anti-coagulation system. Continuous and accurate monitoring is therefore very important for people with high risk factors of thrombosis