Elevated factor VIII level and stroke in patients without traditional risk factors associated with cardiovascular diseases

Abstract

IntroductionHemostasis is affected by interactions between physiological processes, including those connected with the coagulation system, whose essence is converting fibrinogen into fibrin. The role of factor VIII (FVIII) consists in activating factor X, which directly participates in the generation of thrombin, which is able to produce stable fibrin, which in turn forms blood clots. There are divergent opinions regarding the significance of high levels of FVIII in stroke pathogenesis.AimThe aim of our study was to evaluate FVIII activity in individuals with cryptogenic stroke in order to determine a potential relationship between it and cerebral ischemia.Material and methodsNine patients suffering with stroke were used in this study: six women and three men aged 49–63 years. In all of the patients, the presence of known and potential risk factors for stroke had been excluded during previous diagnostic procedures. These patients accounted for 1.2% of the 719 people who suffered a stroke and were hospitalized in 2011 at the Stroke Unit. FVIII activity was examined in each of the nine qualified subjects within 1–2 months of the occurrence of stroke (the first test) and repeated (the second test) in five patients with abnormal results obtained from the first examination.ResultsIncreased activity of FVIII was found in 5 out of 9 patients. In patients with abnormal results, elevated FVIII was found in follow-up examinations in the 8th–10th month following stroke. Hemodynamic abnormalities in carotid or cerebral artery (presence of thrombus) were found in 3 of the 5 patients with increased FVIII levels. In the first 24 hours following stroke the neurological state of patients with abnormal FVIII was worse than individuals with normal FVIII activity. The patients with abnormal FVIII levels were found to be more disabled in the examination of self-dependence on the 90th day after stroke.ConclusionWhen searching for the causes of stroke, it is worth examining the coagulation system, including FVIII concentration, the abnormality of which may play a significant part in brain ischemia. More research is needed to determine the relationship between abnormal FVIII activity and stroke.

Elevated Factor VIII Levels Associated with Acute Graft Occlusion and Arterial and Venous Thrombosis After Off Pump CABG

“…11 Another study found that in patients who had suffered a stroke, those with elevated factor VIII levels were more likely to show evidence of a carotid or cerebral thrombus and presented with more disability when compared with those patients with normal levels of factor VIII. 12 Our case is unique among those in the literature, as the patient was significantly older than what has been documented thus far. We postulate that changes in the coagulation cascade after surgery precipitated these events.…”

Comparison of Factor Viii Activity in O and Non-O Blood Types

“…Kamphuisen stated that only 4% of factor VIII activity >123% may cause the incidence of arterial thrombosis. 13 High factor-VIII activity is the risk factor of thrombosis, with a greater impact on venous thrombosis than arterial thrombosis. 15 In this study, factor VIII activity between O and non-O blood types was not significantly different.…”

“…5 The mechanism of genetic and environmental factors, that leads to a high factor VIII activity, as the cause of thrombosis, is not yet fully known. [13][14][15]…”

“…These results are consistent with a study by O'Donnell. [13][14][15] Several studies have demonstrated that a high activity of factor VIII is persistent and serves as a risk factor for thrombosis, but it has not been known how much the cut-off value is of factor-VIII that leads to thrombosis. 4 The Genetic Analysis of Idiopathic Thrombophilia (GAIT) study found a relationship between factor VIII activity with a Activated Protein C resistance in the pathogenesis of thrombosis.…”

“…Activated Protein C resistance increases the risk of venous thrombotic events. 13,14 High factor-VIII with the possibility of thrombosis is associated with a genetic disorder, that is the presence of the locus on chromosome 18,4,13,14 This study was conducted to determine whether factor VIII activity in non-O blood type was higher than that in O blood type and factor VIII activity in the A, B and O blood types using Sysmex CS-2100i. In addition, the authors also wanted to find out the cause of high-factor VIII activity in O blood type compared to that of non-O, which is still controversial.…”