title: Orthostatic Challenge Shifts the Hemostatic System of Patients Recovered from Stroke toward Hypercoagulability.
abstract: Aims:The objective of our study was to assess the effects of orthostatic challenge on the coagulation system in patients with a history of thromboembolic events and to assess how they compared with age-matched healthy controls.Methods:Twenty-two patients with histories of ischemic stroke and 22 healthy age-matched controls performed a sit-to-stand test. Blood was collected prior to- and at the end of- standing in the upright position for 6 min. Hemostatic profiling was performed by determining thrombelastometry and calibrated automated thrombogram values, indices of thrombin generation, standard coagulation times, markers of endothelial activation, plasma levels of coagulation factors and copeptin, and hematocrit.Results:Orthostatic challenge caused a significant endothelial and coagulation activation in patients (Group 1) and healthy controls (Group 2): Plasma levels of prothrombin fragment F1+2 were increased by approximately 35% and thrombin/antithrombin-complex (TAT) increased 5-fold. Several coagulation variables were significantly altered in Group 1 but not in Group 2: Coagulation times (CTs) were significantly shortened and alpha angles, peak rate of thrombin generation (VELINDEX), tissue factor (TF) and copeptin plasma levels were significantly increased (comparison between standing and baseline). Moreover, the shortening of CTs and the rise of copeptin plasma levels were significantly higher in Group 1 vs. Group 2 (comparison between groups).Conclusion:The coagulation system of patients with a history of ischemic stroke can be more easily shifted toward a hypercoagulable state than that of healthy controls. Attentive and long-term anticoagulant treatment is essential to keep patients from recurrence of vascular events.
authors.affiliation: Institute of Physiological Chemistry, Medical University of Graz Graz, Austria.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Cvirn
authors.affiliation: Department of Neurology, Medical University of Graz Graz, Austria.
authors.forename: Markus
authors.initials: M
authors.lastname: Kneihsl
authors.affiliation: Institute of Physiological Chemistry, Medical University of Graz Graz, Austria.
authors.forename: Christine
authors.initials: C
authors.lastname: Rossmann
authors.affiliation: Institute of Physiological Chemistry, Medical University of Graz Graz, Austria.
authors.forename: Margret
authors.initials: M
authors.lastname: Paar
authors.affiliation: Department of Neurology, Medical University of Graz Graz, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Gattringer
authors.affiliation: Department of Pediatrics, Medical University of Graz Graz, Austria.
authors.forename: Axel
authors.initials: A
authors.lastname: Schlagenhauf
authors.affiliation: Department of Pediatrics, Medical University of Graz Graz, Austria.
authors.forename: Bettina
authors.initials: B
authors.lastname: Leschnik
authors.affiliation: Department of Pediatrics, Medical University of Graz Graz, Austria.
authors.forename: Martin
authors.initials: M
authors.lastname: Koestenberger
authors.affiliation: Institute of Physiological Chemistry, Medical University of Graz Graz, Austria.
authors.forename: Erwin
authors.initials: E
authors.lastname: Tafeit
authors.affiliation: Institute of Physiological Chemistry, Medical University of Graz Graz, Austria.
authors.forename: Gilbert
authors.initials: G
authors.lastname: Reibnegger
authors.affiliation: Gravitational Physiology, Aging and Medicine Research Unit, Institute of Physiology, Medical University of Graz Graz, Austria.
authors.forename: Irhad
authors.initials: I
authors.lastname: Trozic
authors.affiliation: Gravitational Physiology, Aging and Medicine Research Unit, Institute of Physiology, Medical University of Graz Graz, Austria.
authors.forename: Andreas
authors.initials: A
authors.lastname: Rössler
authors.affiliation: Department of Neurology, Medical University of Graz Graz, Austria.
authors.forename: Franz
authors.initials: F
authors.lastname: Fazekas
authors.affiliation: Gravitational Physiology, Aging and Medicine Research Unit, Institute of Physiology, Medical University of Graz Graz, Austria.
authors.forename: Nandu
authors.initials: N
authors.lastname: Goswami
keywords: coagulation; orthostasis; standing; stroke/prevention; thrombin; thrombo-embolism; thrombosis; tissue factor