Coagulation disorders in young adults with acute cerebral ischaemia

Hereditary Thrombophilia Testing Among Hospitalized Patients: Is It Warranted?

Background

Hereditary thrombophilias (HTs) are a group of inherited disorders that predispose the carrier to venous thromboembolism (VTE). It is estimated that 7% of the population has some form of HT. Although testing for HT has become routine for many hospitalized patients, knowing when to order the tests and how to interpret the results remains challenging. In the United States, there are no clear guidelines regarding testing for HT. We conducted a study to evaluate the utilization of HT testing among hospitalized patients to examine its impact on immediate management decisions and overall cost burden. In addition, we discuss the common reasons for healthcare providers to order these tests and review the data behind these reasons in the literature.

Methodology

A retrospective analysis of 2,402 patients who underwent HT testing between February 1, 2016, and January 31, 2018, was conducted. Eligible patients had at least one HT test ordered during hospitalization. The primary outcome was to determine the incidence of positive actionable tests. A positive actionable test was defined as a positive result that changed the anticoagulation intensity, type, or duration. Patients with a history of previous VTE, ongoing medical conditions requiring life-long anticoagulation, or unprovoked VTE were considered non-actionable.

Results

Among the 2,402 patients, 954 patients met the inclusion criteria with a mean age of 54 years. A total of 397 (41.6%) tests were ordered for acute VTE, while the rest were for non-VTE conditions, such as stroke, pregnancy complications, peripheral artery diseases, and others. Only 89 positive tests were actionable (14% of the positive tests, and 9.3% of the total ordered tests). There was a statistically significant association between increasing age and having both a positive test result (p = 0.006) and an actionable test (p = 0.046). The total cost of ordering these tests was estimated to be $566,585.

Conclusions

HT testing in the inpatient setting did not alter management in many cases and was associated with increased healthcare costs. The decision to order these tests should be individualized based on the clinical scenario.

Stroke Secondary to Iron Deficiency Anemia: A Case Report

Cerebrovascular accident is the fifth leading cause of death in the United States, with about 795,000 cases reported to the Centers for Disease Control and Prevention (CDC) each year. Several risk calculators for the development of stroke have been developed throughout the years, but none included iron deficiency anemia (IDA). We therefore would like to highlight the case of a 34-year-old female with severe iron deficiency anemia secondary to menorrhagia who had an ischemic stroke. An extensive workup was done and was negative. Given its significant presence with other comorbidities and various proposed pathogenesis, we propose that iron deficiency anemia be considered as a stroke factor. Studies in optimal hemoglobin or iron levels in patients with stroke to lower comorbidities and predict prognosis may also be beneficial.

Thrombophilia Testing After Ischemic Stroke: Why, When, and What?

Thrombophilia testing is frequently performed after an ischemic stroke, particularly when cryptogenic. However, there is minimal evidence supporting a significant association between most conditions assessed through thrombophilia testing and ischemic stroke, and the rationale for thrombophilia testing in many clinical situations remains uncertain. In this topical review, we review and contextualize the existing data on the risks, predictors, and outcomes of thrombophilic conditions in patients with ischemic stroke. We report that inherited thrombophilias have an uncertain relationship with ischemic stroke. Conversely, antiphospholipid syndrome, an acquired immune-mediated thrombophilia, seems to be a strong risk factor for arterial thromboembolic events, including ischemic stroke, and especially among young patients. Our findings suggest that certain circumstances may warrant targeted thrombophilia testing, such as stroke in the young, cryptogenic stroke, and high estrogen states. Future prospective studies should investigate the utility and cost effectiveness of thrombophilia testing in various stroke settings, including among patients with patent foramen ovale; as well as the optimal secondary stroke prevention regimen in patients with confirmed thrombophilia, particularly if no other potential stroke mechanism is identified.

Prothrombotic factors do not increase the risk of recurrent ischemic events after cryptogenic stroke at young age: the FUTURE study

BACKGROUND

The role of hypercoagulable states and preceding infections in the etiology of young stroke and their role in developing recurrent ischemic events remains unclear. Our aim is to determine the prevalence of these conditions in patients with cryptogenic stroke at young age and to assess the long-term risk of recurrent ischemic events in patients with and without a hypercoagulable state or a recent pre-stroke infection with Borrelia or Syphilis.

PATIENTS AND METHODS

We prospectively included patients with a first-ever transient ischemic attack or ischemic stroke, aged 18-50, admitted to our hospital between 1995 and 2010. A retrospective analysis was conducted of prothrombotic factors and preceding infections. Outcome was recurrent ischemic events.

RESULTS

Prevalence of prothrombotic factors did not significantly differ between patients with a cryptogenic stroke and with an identified cause (24/120 (20.0%) and 32/174 (18.4%) respectively). In patients with a cryptogenic stroke the long-term risk [mean follow-up of 8.9 years (SD 4.6)] of any recurrent ischemic event or recurrent cerebral ischemia did not significantly differ between patients with and without a hypercoagulable state or a recent infection. In patients with a cryptogenic stroke 15-years cumulative risk of any recurrent ischemic event was 24 and 23% in patients with and without any prothrombotic factor respectively.

CONCLUSIONS

The prevalence of prothrombotic factors and preceding infections did not significantly differ between stroke patients with a cryptogenic versus an identified cause of stroke and neither is significantly associated with an increased risk of recurrent ischemic events after cryptogenic stroke.

Haemostatic parameters, platelet activation markers, and platelet indices among regular plateletpheresis donors

OBJECTIVE

Plateletpheresis is generally a safe procedure for platelet donation. Studies on the effects of haemostatic parameters and possible association between automated plateletpheresis and hypercoagulable state are limited. Hence, this study aimed to investigate the effects of plateletpheresis on regular donors using haemostatic parameters, i.e. natural anticoagulant proteins, platelet indices, and platelet activation markers.

METHODS

A total of 139 participants (plateletpheresis donors and normal controls) were recruited and divided into two groups: Group 1 participants who underwent tests for haemostatic and platelet indices and Group 2 participants who underwent tests for platelet activation markers using CD62P and PAC-1 monoclonal antibodies.

RESULTS

A significant mild shortening of prothrombin time and platelet activation were demonstrated (by increased CD62P and PAC-1 markers) among regular plateletpheresis donors as compared to healthy controls. The current pre-donation platelet count of plateletpheresis donors was significantly lower than their mean baseline platelet count obtained before their first plateletpheresis procedure. However, no significant differences were observed for the other platelet parameters (platelet count, mean platelet volume, platelet distribution width, activated partial thromboplastin time, protein C, protein S, antithrombin, and von Willebrand Factor antigen) between plateletpheresis donors and healthy controls.

CONCLUSION

This study concludes that regular plateletpheresis is a safe procedure. A possibility of mild platelet activation among regular donors requires further confirmation. However, pre-analytical platelet and FVII activations could occur in vitro contributing to these findings.

Homonymous hemianopia in the primary antiphospholipid syndrome

A woman aged 26 years was referred by her GP to the eye casualty department with sudden-onset left homonymous hemianopia and right-sided headache. Full ophthalmic examination was normal with the exception of a left homonymous hemianopia confirmed with automated perimetry. Urgent CT imaging revealed a non-haemorrhagic cerebral infarct in the right parieto-occipital region. Subsequent blood tests confirmed a diagnosis of antiphospholipid syndrome with positivity in IgG anticardiolipin antibody, IgG anti-β2-GP1 antibody and the Lupus anticoagulant screen. MRI revealed extensive congenital abnormality at the Circle of Willis, affecting the right half of circulation. The unique dual pathologies may explain her predisposition to right-sided cerebral infarctions. This case highlights a rare but potentially fatal cause of visual disturbance in a young patient, and the importance of the multidisciplinary team approach in diagnosis and management.

Idiopathic Intracranial Hypertension: Associations with Thrombophilia and Hypofibrinolysis in Men

The existence of an association between idiopathic intracranial hypertension (IIH) and coagulation disorders in men was assessed prospectively. Microthrombi, associated with thrombophilia-hypofibrinolysis, occlude arachnoid sinus villi, thus reducing resorption of cerebrospinal fluid, leading to IIH. Ten consecutively referred men with IIH, nine whites, one African American, median age 36 years, were 2 to 1 matched by age and race by healthy male controls. Polymerase chain reaction assays were done for four thrombophilic and one hypofibrinolytic gene mutations: G1691A factor V Leiden, G20210A prothrombin, C677T MTHFR, platelet glycoprotein IIb/IIIa (PL A1/A2), and 4G/5G polymorphism of the plasminogen activator inhibitor (PAI-1) gene promoter. Coagulation measures in plasma included dilute Russel’s viper venom time (dRVVT), activated partial thromboplastin time (aPTT), the lupus anticoagulant, factor VIII, factor XI, plasminogen activator inhibitor activity (PAI-Fx), protein C antigenic, protein S total (antigenic), protein S free (antigenic), antithrombin III (functional), and resistance to activated protein C (RAPC). Tests performed on serum included anticardiolipin antibodies, homocysteine, and Lp(a). The body mass index was 40 kg/m2 or greater (extremely obese) in two men, 30 to 40 kg/m2(obese) in three, and was 25 to 30 kg/m2 in five (overweight). Cases differed from controls for inherited 4G4G homozygosity of the PAI-1 gene, four of 10 (40%) vs. one of 20 (5%), Fisher’s p [pf]= .031, and for high levels (>21.1 U/mL) of the hypofibrinolytic PAI-1 gene product, PAI-Fx, 5 of 10 (50%) vs. one of 18 (6%), pf = .013. Thrombophilic factor VIII was high (≥ 150%) in three of 10 (30%) cases vs. zero of 16 (0%) controls, pf=. 046. The thrombophilic lupus anticoagulant was present in two of 10 (20%) cases vs. zero of 32 (0%) controls, pf = .052. Heritable hypofibrinolysis and heritable and acquired thrombophilia appear, speculatively, to be treatable etiologies of IIH in men. Understanding contributions of hypofibrinolysis and thrombophilia to the development of IIH should facilitate development of novel new approaches to treat this often-disabling neurologic disorder.

The estimated frequency of antiphospholipid antibodies in young adults with cerebrovascular events: a systematic review

BACKGROUND

Around 10% of all thrombotic cerebrovascular events (CVE) occur in young population and in a large proportion of those the trigger remains undetermined. Antiphospholipid antibodies (aPL) are recognised risk factors for ischaemic stroke and recurrent thrombotic events; however, the frequency of aPL in young people with CVE is still an unresolved issue.

OBJECTIVES

To estimate the frequency of aPL in young adults with CVE and to determine whether aPL-positive young individuals are at greater risk of CVE when compared with individuals without aPL by systematically reviewing the literature.

METHODS

Medline reports published between 1970 and 2013 investigating the presence of aPL in young patients (<50 years old) with CVE were included. The median frequency for positive aPL, including lupus anticoagulant, anticardiolipin antibodies (aCL) and antibodies against β2Glycoprotein I (anti-β2GPI), was calculated for stroke and transient ischaemic attacks.

FINDINGS

This systematic review is based on available data from 5217 patients and controls from 43 studies analysing the frequency of aPL in young patients with CVE. The overall aPL frequency was estimated as 17.4% (range 5%-56%) for any CVE, 17.2% (range 2%-56%) for stroke and 11.7% (range 2%-45%) for transient ischaemic attack (TIA). The presence of aPL increased the risk for CVE by 5.48-fold (95% CI 4.42 to 6.79). Based on available data, the frequency of aPL in young patients with CVE can be estimated at 17%, rising up to 22% for aCL in patients with stroke. The presence of aPL seems to confer a fivefold higher risk for stroke or TIA when compared with controls. However, variability in test reproducibility and cut-off definition still represent an important methodological limitation for the current diagnostic testing for aPL. These observations should be confirmed by appropriately designed population studies.

Acute ST Elevated Myocardial Injury due to Coronary Thrombosis during Thoracic Endovascular Aortic Repair in Patient with Protein S Deficiency

A 71-year-old woman who had suffered from pulmonary thromboembolism with deep vein thrombosis for 12 years presented the hospital with a huge thoracic aortic aneurysm. During thoracic endovascular therapy, she had a sudden coronary artery occlusion without having organized stenosis or plaque rupture even under the dual antiplatelet treatment and heparinization. She turned out to be having a protein S deficiency. A procedure related thrombotic adverse event in patient with protein S deficiency is very rare, so we report a case with literature review.

Protein-C deficiency presenting as pulmonary embolism and myocardial infarction in the same patient

Plasma protein-C exerts anticoagulatory effects by inactivating factors V and VIII. Hereditary protein C deficiency is transmitted as an autosomal dominant disorder. Homozygous individuals usually develop purpura fulminans as newborns; heterozygous protein C-deficient individuals are at increased risk for venous thrombosis and pulmonary embolism. However, arterial thrombosis occurring as a result of congenital protein-C deficiency is still controversial. We describe a young patient with heterozygous protein-C deficiency who experienced both pulmonary embolism as well as myocardial infarction due to thrombotic occlusion without underlying major risk factors. Acute myocardial infarction in young without underlying major risk factors may be evaluated for protein c deficiency.

Patent foramen ovale and atrial septal aneurysm can cause ischemic stroke in patients with antiphospholipid syndrome

The purpose of the present study was to evaluate the contributions of embolic etiologies, patent foramen ovale (PFO) and atrial septal aneurysm (ASA) to the pathogenesis of ischemic stroke in patients with antiphospholipid syndrome (APS). We performed transesophageal echocardiography (TEE) examination for consecutive stroke patients who had been diagnosed with APS (APS group) to detect potential embolic sources. APS was diagnosed based on the modified Sapporo criteria. The control stroke group comprised age- and sex-matched cryptogenic stroke patients undergoing TEE. We assessed and compared the clinical characteristics and TEE findings between stroke patients with APS and control stroke groups. Among 582 patients, nine patients (nine women; mean age, 50 ± 18 years) were classified into the APS group. In 137 patients undergoing TEE, 41 age-matched female stroke patients were recruited to the control stroke group. Prevalences of PFO and ASA were significantly higher in the APS group than in the control stroke group (89 vs. 41 %, p = 0.027; 67 vs. 20 %, p = 0.015, respectively). Multiple logistic regression analysis showed that PFO (odds ratio (OR), 13.71; 95 % confidence interval (CI), 1.01-185.62; p = 0.049) and ASA (OR, 8.06; 95 % CI, 1.17-55.59; p = 0.034) were independently associated with the APS group. PFO and ASA were strongly associated with the APS group, and could thus represent potential embolic sources in ischemic stroke patients with APS.

Protein S deficiency: Recurrent ischemic stroke in young

Stroke in young poses a major health problem. Thrombophilic factors have been implicated in 4-8% of the young strokes worldwide. Protein S deficiency is a rare cause of recurrent ischemic stroke in young population. Only a few sporadic cases have been described in the literature. We are reporting a case of protein S deficiency-related recurrent ischemic stroke in a 16-year-old girl. Early diagnosis and targeted approach can help such patients to prevent recurrent thrombotic episodes.

Cerebral embolism from Libman-Sacks endocarditis

Libman-Sacks endocarditis consists of aseptic valvular abnormalities, associated with systemic lupus erythematosus and antiphospholipid syndrome. Embolic ischaemic stroke is a possible clinical presentation. The authors present the case of a woman in her fourth decade who developed central facial palsy after several transient ischaemic attacks with visual loss. Cerebral imaging revealed multiple small ischaemic lesions in the right hemisphere. The transoesophagic echocardiogram showed mitral vegetations and she tested positive for antiphospholipid antibodies. She underwent mitral valve replacement for a mechanical prosthesis due to extensive valvular damage and started anticoagulation. The valve's microbiological exams were negative establishing the diagnosis of libman-sacks endocarditis. Endocarditis should be suspected with sequential cerebral ischaemia in patients of all ages. Valvular surgery is the mainstay of treatment in recurrent embolic events. Association with antiphospholipid antibodies is common yet a poor-known fact. The patient is currently asymptomatic on warfarin and aspirin, with a normal functioning mitral prosthesis.

Risk factors for ischemic stroke and transient ischemic attack in patients under age 50

To analyze risk factors for ischemic stroke and transient ischemic attack (TIA) in young adults under the age of 50. To make recommendations for additional research and practical consequences. From 97 patients with ischemic stroke or TIA under the age of 50, classical cardiovascular risk factors, coagulation disorders, history of migraine, use of oral contraceptives, cardiac abnormalities on ECG and echocardiography, and the results of duplex ultrasound were retrospectively analyzed. Literature was reviewed and compared to the results. 56.4% of the patients had hypertension, 12.1% increased total cholesterol, 20% hypertriglyceridemia, 31.5% an increased LDL-level, 32.6% a decreased HDL-level and 7.2% a disturbed glucose tolerance. Thrombophilia investigation was abnormal in 21 patients and auto-immune serology was abnormal in 15 patients. Ten of these patients were already known with a systemic disease associated with an increased risk for ischemic stroke (i.e. systemic lupus erythematosus). The ECG was abnormal in 16.7% of the cases, the echocardiography in 12.1% and duplex ultrasound of the carotid arteries was in 31.8% of the cases abnormal. Conventional cardiovascular risk factors are not only important in patients over the age of 50 with ischemic stroke or TIA, but also in this younger population under the age of 50. Thrombophilia investigation and/ or autoimmune serology should be restricted to patients without conventional cardiovascular risk factors and a history or other clinical symptoms associated with hypercoagulability and/ or autoimmune diseases.

Hypercoagulation Testing in Ischemic Stroke

Context.—The utility of laboratory testing for hypercoagulability in the setting of stroke is uncertain.

Objective.—To review the current literature and to make recommendations with regard to laboratory testing for various hypercoagulability risk factors for ischemic stroke.

Data Sources.—Published articles studying the utility of various hypercoagulation tests in predicting initial and/or recurrent stroke or transient ischemic attack as well as cerebral vein thrombosis were collected and reviewed, with an emphasis on prospective studies.

Conclusions.—Certain tests, such as C-reactive protein, homocysteine, antiphospholipid antibodies, and lipoprotein(a), may be useful in patients with a history of stroke or at high risk for stroke, as evidenced by prospective data. Factor V Leiden, prothrombin G20210A, protein C, protein S, and antithrombin are not recommended for routine testing but may be useful in certain populations, such as in pediatric patients or in patients with cerebral vein thrombosis.

Evidence of hypercoagulability and inflammation in young patients long after acute cerebral ischaemia

INTRODUCTION

Young subjects with acute cerebral ischaemia - stroke or transient ischaemic attack - form an etiologically heterogeneous and often not clearly explained group of patients. The aim was to investigate possible disturbances in haemostasis and inflammation long after an acute cerebral ischaemic event.

MATERIALS AND METHODS

Forty-four consecutive patients referred after having suffered from acute cerebral ischaemia before the age of 45 participated 1 to 9 years (median value 5 years) after the event. At the time of blood sampling 33 (75%) patients were receiving antithrombotic treatment. Forty-six apparently healthy subjects of the same age group served as controls. In all subjects global haemostasis parameters (overall haemostasis, coagulation and fibrinolytic potential), thrombophilia, several markers of haemostasis activation and inflammation were determined.

RESULTS

Patients did not differ from controls in most of the conventional risk factors and the presence of most forms of thrombophilia, although in seven (17.5%) patients the weak presence of lupus anticoagulants was observed. Patients had significantly increased overall haemostasis and coagulation potential, increased soluble P-selectin and D-dimer, decreased overall fibrinolysis potential and increased fibrinogen and C-reactive protein compared to controls. The subgroups of patients receiving antiplatelet treatment, with thrombophilia and recurrent acute cerebral ischaemia, did not differ significantly from the other patients.

CONCLUSIONS

In young patients long after acute cerebral ischaemia an imbalance in the haemostatic system and a minor, but significant degree of inflammation was detected. The mechanisms behind haemostatic imbalance seem to be enhanced thrombin generation, platelet activation and depressed fibrinolysis.

Thrombophilien bei Patienten mit isch�mischem Schlaganfall

Patients with ischemic stroke are sometimes found to have an underlying inherited (deficiency of protein C, protein S, antithrombin III, activated protein C resistance, prothrombin gene mutation, hyperhomocysteinemia) or acquired thrombophilia (lupus anticoagulant and anticardiolipin antibodies, hyperhomocysteinemia). Patient selection for thrombophilia screening is, therefore, a frequent question in managing patients with ischemic stroke. In this review we discuss patient selection and timing for laboratory tests for thrombophilia screening in stroke patients based on a literature review and we calculated overall costs per year in Germany for testing patients older than 18 years with an ischemic stroke of undetermined cause. As there is a lack of studies comparing anticoagulation with antiplatelet therapy in patients with diagnosed thrombophilia, laboratory screening for thrombophilia even in a selected group of patients with cryptogenic ischemic stroke remains of questionable value at present. An exception appears to be testing for lupus anticoagulant and anticardiolipin antibodies in younger patients with suspected antiphospholipid syndrome (two positive test results necessary), because anticoagulation seems to be superior to aspirin in patients with antiphospholipid syndrome.

Idiopathic intracranial hypertension, polycystic-ovary syndrome, and thrombophilia

We studied thrombophilia, hypofibrinolysis, and polycystic-ovary syndrome (PCOS) in 65 women consecutively referred because of idiopathic intracranial hypertension (IIH) as a means of better understanding the origin of IIH, with the ultimate goal of developing novel medical therapies for IIH. Our hypothesis: IIH results in part from inadequate drainage of cerebrospinal fluid (CSF) resulting from thrombotic obstruction to CSF resorption-outflow, favored by thrombophilia-hypofibrinolysis. We conducted the polymerase chain reaction (PCR) and assessed serologic coagulation measures in 65 women (64 of them white) with IIH, PCR in 102 healthy white female controls (72 children, 30 age-matched adults), and serologic measures in the 30 adults. Of the 65 patients, 37 (57%) were found to have PCOS; 16 (43%) were obese (BMI > or = 30 to < 40), and 19 (51%) were extremely obese (BMI > or = 40). Of the 65 women with IIH, 25 (38%) were homozygous for the thrombophilic C677T MTHFR mutation, compared with 14% of controls (14/102) ( P = .0002). Thrombophilic high concentrations of factor VIII (>150%) were present in 9 of 65 (14%) IIH cases, compared with 0 of 30 controls (0%) (Fisher's p [p f ] = .053). An increased concentration of lipoprotein A (> or = 35 mg/dL), associated with hypofibrinolysis, was present in 19 of 65 IIH cases (29%), compared with 3 of 30 controls (10%) (p f = .039). IIH occurred in 18 of 65 IIH patients taking estrogen-progestin contraceptives (28%), in 6 patients taking hormone-replacement therapy (9%), and in 5 pregnant subjects (8%). We speculate that PCOS, associated with obesity and extreme obesity, is a treatable promoter of IIH. We also speculate that if thrombophilia-hypofibrinolysis and subsequent thrombosis are associated with reduced CSF resorption in the arachnoid villi of the brain, thrombophilia and hypofibrinolysis-often exacerbated by thrombophilic exogenous estrogens, pregnancy, or the paradoxical hyperestrogenemia of PCOS-are treatable promoters of IIH.

Infarctus cérébraux artériels d’origine hématologique : expérience lausannoise et revue de la littérature

INTRODUCTION

Hematological diseases are seldom found as the etiology of ischemic strokes, but are frequently investigated by expensive laboratory tests after a first cerebral vascular event.

METHODS

In the Lausanne Stroke Registry, we retrospectively reviewed the cases of patients hospitalized between 1979 and 2001 for a first ischemic arterial stroke which was attributed to a hematological etiology. Of 4697 patients, 22 (0.47 per cent) had a stroke due to one of the following hematological pathology: polycythemia vera (4), secondary polycythemia (4), essential thrombocytemia (2), secondary thrombocytosis (4), multiple myeloma (1), CIVD (1), protein S deficiency (1), antiphospholipid antibody syndrome (4), moderate homocysteinemia (1). A literature review was undertaken for each hemopathy.

CONCLUSION

In light of the results of these data, we concluded that a complete blood count provides sufficient hematological screening for the majority of patients hospitalized for an arterial stroke. The antiphospholipid antibody syndrome is a rare cause of cerebral infarction, which needs to be investigated in young patients, in cases of multiple or recurring stroke or in the presence of a typical history. Inherited thrombophilias are not a significant risk factor for arterial cerebral infarction and their investigation is only warranted for a sub-group of young patients with a cryptogenic stroke, in which group the prevalence is slightly increased. Moderate homocysteinemia must be considered as a cerebrovascular risk factor of minor importance, but potentially treatable by a substitution of vitamin B12, B6 and folates. The efficacy of this substitution in the prevention of cardiovascular events needs yet to be demonstrated.

Comparison of results of percutaneous closure of patent foramen ovale for paradoxical embolism in patients with versus without thrombophilia

We investigated the efficacy of transcatheter patent foramen ovale (PFO) closure to prevent recurrent cerebral ischemic events in patients who did and those who did not have thrombophilia. Patients who have a PFO and an associated thrombophilia may have an increased risk of cerebral ischemic events. Seventy-two consecutive patients (mean age 42 +/- 13 years) underwent percutaneous PFO closure because of a cerebral stroke (51%) or a transient ischemic attack (49%). A thrombophilia was found in 20 patients (28%). A large right-to-left shunt through the PFO was found in 44 patients (61%) and an atrial septal aneurysm was found in 39 (54%). After the first event, 18 of 20 patients (90%) with a thrombophilia received oral anticoagulation. Before closure, patients who had a thrombophilia also had a higher rate of recurrences than patients who did not (p <0.0001), despite a similar follow-up (p = 0.14) and regardless of shunt entity (p = 0.59), presence of an atrial septal aneurysm (p = 0.98), and a prevalence of cardiovascular risk factors (p = 0.44). PFO closure was successful in all patients. Five patients (8%) had a residual shunt at 6 months. At 20 +/- 11 months after PFO closure, 3 recurrent events occurred (4%), and the recurrence rate was similar in patients who did and those who did not have a thrombophilia (p = 0.25). Thus, in patients who have a cryptogenic stroke, the association of a PFO with a thrombophilia significantly increases the risk of recurrences. Thus, transcatheter PFO closure is effective for preventing recurrences in patients who have a thrombophilia.

Do antiphospholipid antibodies increase the long-term risk of thrombotic complications in young patients with a recent TIA or ischemic stroke?

BACKGROUND

The purpose of our study was to determine the relative risk of thrombotic events in young patients with a recent TIA or ischemic stroke and positive antiphospholipid antibodies (aPL).

METHODS

We included 128 consecutive patients aged 18-45 years with a recent TIA or ischemic stroke. All patients underwent computed tomography scanning and were screened for cardiovascular risk factors, cardiac disorders and large vessel disease. Lupus anticoagulant (LA) was screened for by an APTT-based assay and a diluted PT-assay. Anticardiolipin antibodies (aCL) were tested by enzyme-linked immunosorbent assay, using cardiolipin and anti-human IgG and IgM. Thrombotic events could be TIA, stroke, myocardial infarction, deep venous thrombosis or pulmonary embolism. Product limit estimates of the time free of TIA or stroke and of the time free of any thrombotic event were made. The relative risk was estimated by means of a Cox proportional hazards regression model.

RESULTS

Of the 128 patients, 22 (17.2%) had aPL. The mean follow-up was 3 years and 3 months (range 41 days to 6 yrs). The incidence of any thrombotic event per 100 patient years of follow-up was 9.0, and the incidence of recurrent stroke or TIA was 7.9. The relative risk of any thrombotic event in patients with aPL was 0.9 (95% CI: 0.3-2.4) and for recurrent ischemic stroke or TIA 0.7 (95% CI: 0.3-2.2).

CONCLUSION

In young patients with a recent TIA or ischemic stroke, aPL do not seem to be a strong risk factor for recurrent stroke or TIA, nor for other thrombotic complications.

Thrombin generation in platelet-rich plasma as a tool for the detection of hypercoagulability in young stroke patients

The time course of the concentration of active thrombin in clotting plasma (the thrombogram) was measured by subsampling from platelet-rich plasma (PRP) and continuous chromogenic measurement of platelet-poor plasma (PPP) in 41 stroke patients under the age of 50, in whom stroke could not be attributed to cardioembolic disease, arterial dissection or vasculitis. A significant increase in the area under the thrombogram (endogenous thrombin potential, ETP) was seen in 23 patients. In 9 of them, ETP was increased in PRP but normal in PPP. High ETP in PRP was significantly associated with stroke, both in the middle and in the highest tercile of the ETP (odds ratio 5.1, range 1.8-15.1, and 3.7, range 1.3-10.3, respectively). A decreased sensitivity to the inhibitory action of thrombomodulin (TM) on thrombin generation was observed in 5 of 37 cases. No further definition of the cause of increased thrombin generation or TM resistance was attempted, except for the role of von Willebrand factor (vWF). ETP in PRP, platelet-derived procoagulant activity and vWF were correlated and higher in patients than in controls (p=0.002, p=0.045 and p=0.0006, respectively). This confirms the correlation between vWF level and stroke at young age found in epidemiological studies. It suggests that the role of vWF in thrombin generation, which has been demonstrated in vitro, may be the underlying mechanism of this correlation. In summary, hypercoagulability, defined as an increased capacity of the platelet plasma system to form thrombin, is found in over half of the patients under 50 years with an otherwise unexplained stroke. Sometimes it is due to increased plasma factor activity, sometimes to an increased procoagulant activity of the platelets.

Antiphospholipid antibodies as a risk factor for atherosclerotic events in renal transplant recipients

BACKGROUND

Epidemiologic studies reported that antiphospholipid antibodies (APAs) were independent predictors of atherosclerotic events. We recently reported a high prevalence of APAs in renal transplant recipients. Nevertheless, the role of APAs on atherosclerotic events has not been prospectively studied in this high-risk population.

METHODS

Participants in the study were 324 consecutive renal transplant recipients. Patients were enrolled between January 1996 and May 1998 and followed up until June 2002.

RESULTS

The patients were followed for a mean duration of 62 +/- 26 months. Eighty seven (26.8%) patients exhibited APAs. We found a slight, but significant, correlation between total plasma homocysteine (tHcy) concentration and anticardiolipin (ACA) titers (r = 0.26; P = 0.036). Fifty six athersclerotic events (17.2%) occurred in 54 patients. Atherosclerotic events occurred more frequently in patients with APAs (33% vs. 9%; P = 0.0003) and ACAs levels were higher in patients who experienced atherosclerotic events (23.7 +/- 13.1 IU vs. 13.9 +/- 9.4 IU; P = 0.003). APAs were associated with an increased risk of atherosclerotic events (RR, 2.82; 95% CI, 1.17 to 5.31). Cox regression analysis also revealed that age above the median (RR, 5.21; 95% CI, 1.67 to 17.13), a previous history of cardiovascular disease (RR, 3.54; 95% CI, 1.57 to 10.43), hyperhomocysteinemia (RR, 4.01; 95% CI, 1.22 to 14.61), and current smoking (RR, 2.17; 95% CI, 1.01 to 6.72) were risk factors for atherosclerotic events.

CONCLUSION

The presence of APAs is an independent cardiovascular risk factor in renal transplant recipients. Prevention trials are necessary to assess the efficacy and safety of anticoagulation therapy in transplant patients with APAs.

Idiopathic intracranial hypertension: associations with coagulation disorders and polycystic-ovary syndrome

To better understand potentially reversible causes of idiopathic intracranial hypertension (IIH), also known as pseudotumor cerebri, and an apparent association of IIH with polycystic-ovary syndrome (PCOS), we assessed associations of IIH with coagulation disorders and with PCOS in 38 women with well-documented IIH. Fifteen women were found to have PCOS; 14 of them were obese, with a body-mass index (BMI) greater than 30 kg/m(2), and 10 were extremely obese (BMI > or = 40). Factor VIII concentration was high (>150%) in 9 of 38 (24%) IIH cases, compared with 0 of 40 healthy adults controls (P(f) =.0009). Familial aggregation of high concentrations of factor VIII, associated with thrombophilia, was documented in all 5 of the 9 high-level factor VIII probands' families who were sampled. Activated partial thromboplastin time (APTT) was prolonged (> or =31.5 seconds) in 10 of 38 (26%) IIH cases, compared with 1 of 32 (3%) controls (P(f) =.009) and, in 4 of these cases, was accompanied by the lupus anticoagulant. Plasminogen activator inhibitor activity (PAI-Fx) was high (>21.1 U/mL) in 9 of 38 cases (24%), compared with 1 of 40 controls (3%) (P(f) =.006). Lipoprotein A was high (> or =35 mg/dL) in 13 of 37 cases (35%), compared with 5 of 40 controls (13%) (P(f) =.03). IIH cases did not differ (P >.05) from controls for homocysteine, proteins C and S, free S, antithrombin III, ACLAs IgG and IgM, dilute Russell's viper venom time, Factor XI, factor V Leiden G1691A, G20210A prothrombin, C677T MTHFR, plasminogen activator inhibitor 4G/5G, or platelet glycoprotein PL A1A2 mutations. Exogenous estrogens (n = 23), clomiphene (n = 1), or pregnancy (n = 4) accompanied the first appearance of IIH in 28 women. PCOS and coagulation disorders, often augmented by exogenous estrogens or pregnancy, are associated with IIH.

Arterial thromboembolism in pregnancy

Arterial occlusion resulting from primary thrombus formation in an artery or due to embolization from a site elsewhere in the circulation is uncommon in women of childbearing age. Myocardial infarction, stroke and peripheral arterial occlusion are rare in pregnant or puerperal women. Although atherosclerosis is the most common cause of arterial thromboembolism in the general population, other mechanisms--for example, prosthetic heart valves and drugs which cause vasospasm--are also important in young and pregnant patients. The clinical sequelae of arterial thromboembolism include sudden death and significant long-term morbidity. The best management must be the recognition of women at risk and, where possible, risk reduction and the introduction of measures to prevent acute events.

The prevalence of protein C, protein S, and antithrombin III deficiency in non-APS/SLE Chinese adults with noncardiac cerebral ischemia

Protein C (PC), protein S (PS), and antithrombin III (AT-III) are vital thrombin antagonists in circulation. However, the prevalence of these natural inhibitors for cerebral ischemia is barely mentioned in the Chinese population. The prevalence of PC, PS, and AT-III deficiency in Chinese adults with cerebral ischemia is reported. The study subjects were free of antiphospholipid antibody syndrome or systemic lupus erythematosus. Cardiac, liver, and renal function were normal. An overall rate of thrombophilia was 27%. PS deficiency was the most common disorder, followed by PC with PS and PC deficiency. There was only one patient with AT-III deficiency. No gender was specific for thrombophilia. However, PS deficiency was predilected in young adults. A positive correlation between PC and AT-III was achieved in patients with a normal PC activity but not PC deficiency. There was no correlation between AT-III or PS. The odds ratios of PC and PS were 5.29 and 2.86, respectively. Accordingly, an inability for thrombin antagonization by the PC/PS axis may relate to the occurrence of cerebral ischemia in the Chinese population. AT-III seems to display a minor role only.

Laboratory evaluation of hypercoagulability with venous or arterial thrombosis

OBJECTIVE

To provide recommendations for hypercoagulation testing for patients with venous, arterial, or neurovascular thrombosis, as reflected in the medical literature and the consensus opinion of recognized experts in the field.

DATA SOURCES, EXTRACTION, AND SYNTHESIS

The authors extensively examined the literature and current practices, and prepared a draft manuscript with preliminary recommendations. The draft manuscript was circulated to each of the expert participants (n = 30) in the consensus conference prior to the convening of the conference. The manuscript and recommendations were then presented at the conference for discussion. Recommendations were accepted if a consensus of the 28 experts attending the conference was reached. The discussions were also used to revise the manuscript into its final form.

CONCLUSIONS

The resulting article provides 17 recommendations for hypercoagulation testing in the setting of venous, arterial, or neurovascular thrombosis. The supporting evidence for test selection is analyzed and cited, and consensus recommendations for test selection are presented. Issues for which a consensus was not reached at the conference are also discussed.

Antiphospholipid antibodies in the acute phase of cerebral ischaemia in young adults: a descriptive study of 139 patients

A total of 139 young stroke patients were consecutively examined and tested for antiphospholipid antibodies (APLA) to evaluate the role of these antibodies in cerebral ischaemia before the age of 45. APLA were found in 28.8% of patients. Two factors, hypertriglyceridaemia and alcohol abuse, were significantly more frequent in patients with a positive APLA test. The demographic characteristics, other risk factors, history of prior thrombotic events and distribution of aetiopathogenic types of cerebral ischaemia were not different in patients with or without APLA. Laboratory assays for APLA were highly positive for only two patients, who both had autoimmune diseases. These results suggest that with the exception of a clinical context of antiphospholipid syndrome or other autoimmune diseases, the usefulness of this diagnostic tool in the management of cerebral ischaemia remains limited.

Evidence that anticardiolipin antibodies are independent risk factors for atherosclerotic vascular disease

Thrombophilic anticardiolipin antibodies (ACLAs) are independent risk factors for atherosclerotic vascular disease. We suggest that ACLAs IgG and IgM be routinely measured as ancillary atherothrombotic risk factors in all patients with atherosclerotic vascular disease events, in those at high risk for atherosclerotic vascular disease, and in those in whom thrombosis is a major pathoetiology.