Clot Waveform Analysis: From Hypercoagulability to Hypocoagulability - A Review

CONTEXT.—

Prothrombin time (PT) and activated partial thromboplastin time (aPTT) are coagulative screening tests used for the diagnosis of several pathologic conditions, such as liver failure, coagulation factor deficiencies, anti-phospholipid antibodies (lupus anticoagulant), and factor VIII inhibitors. A new test was developed several years ago to detect the amount of thrombin generated during plasma clotting, using low tissue factor concentrations and fluorogenic substrates, and it has since been used successfully in conditions ranging from hypocoagulable to hypercoagulable states. However, the test is expensive and difficult to perform in nonspecialized laboratories, and efforts have thus been made to find an economic and easily implementable test suitable for routine use, even in nonspecialist laboratories.

OBJECTIVE.—

To evaluate clot waveform analysis (CWA) of PT and aPTT, aiming to show the dynamics of clot formation; that is, the "hidden" features of both tests. CWA can be implemented by using an automated coagulometer with dedicated software. The aim of this review was to evaluate whether CWA is able to detect both hypercoagulative and hypocoagulative states.

DATA SOURCES.—

Using MedLine, we searched and retrieved articles relating to CWA. We only considered articles published in English, but with no limits in terms of article type, publication year, or geography.

CONCLUSIONS.—

CWA was shown to be a reliable test in patients with both hypercoagulable and hypocoagulable states. It represents a simple and inexpensive global test that can easily provide information on the behavior of the coagulation system. Both the first and second derivatives are computed by using dedicated software implemented with an on-board algorithm in a routine automated coagulometer.

Contraceptives and Thrombosis: An Intertwined Revolutionary Road

The development of oral contraceptives (OCs) began in 1921 and continued in the following years until the first regulatory approval from the Food and Drug Administration was granted in 1960. However, it took several years to realize that OCs presented an important but not frequent risk of venous thrombosis. Several reports ignored this dangerous effect and only in 1967 the Medical Research Council clearly stated this as an important risk. Later, research led to the formulation of second-generation OCs containing progestins, which nevertheless presented an increased thrombotic risk. In early 1980s, OCs containing third-generation progestins were introduced into the market. Only in 1995, it became clear that these new compounds induced a higher thrombotic risk than that related to the second-generation progestins. It appeared clear that the modulating action of progestins was against the procoagulant activity of estrogens. Lastly, at the end of the 2000s, OCs containing natural estrogens and a fourth-generation progestin (dienogest) became available. The prothrombotic effect of those natural products was not different from that of preparations containing second-generation progestins. Moreover, research over the years has produced much data on risk factors associated with OCs use such as age, obesity, cigarette smoking, and thrombophilia. These findings allowed us to better assess the individual thrombotic risk (both arterial and thrombotic) of each woman before offering an OC. Furthermore, research has shown that in high-risk people the use of single progestin is not dangerous as far as thrombosis is concerned. In conclusion, the OCs road has been long and difficult but has led to a great and unthinkable scientific and social enrichment since the 1960s.

Do we need more guidance on thrombophilia testing? Challenges and special considerations

INTRODUCTION

Thrombophilia testing (TT) is a laboratory procedure designed to detect the risk factors involved in the pathogenesis of vascular occlusions. The role of TT is also controversial because it has a limited impact on the choice and duration of antithrombotic treatments.

AREAS COVERED

We reviewed, by examining MEDLINE up to October 2023. Accepted and not accepted thrombophilia markers are discussed along with the appropriateness or not of prescribing TT in several conditions such as: provoked and unprovoked venous thromboembolism (VTE), women who are planning a pregnancy whose relatives had VTE or have a hereditary thrombophilia, before assumption of estro-progestins, after multiple pregnant loss, arterial thrombosis, retinal vein occlusion, and splanchnic vein thrombosis.

EXPERT OPINION

TT is not essential in the management of VTE, but it may be useful for limiting adverse events in case of thrombophilia. We expose our criticism of items afforded by other guidelines by presenting our opinion based on both the scientific evidence and clinical practice. We also deal with common mistakes in prescribing and interpretations of TT hoping to purpose an educational approach on this topic. Finally, we emphasize the creation of the expert in hemostasis and thrombosis who should be present in every hospital.

Hormones and thrombosis: the dark side of the moon

BACKGROUND

The main drawback of oral contraceptives (OC) and hormone replacement therapy (HRT) is an increased risk of venous and, to a lesser extent, arterial thrombosis.

MATERIALS AND METHODS

This narrative, case-based review describes the effect of available estrogens and progestogens on the hemostatic system and their potential impact on the risk of thrombosis. Clinical cases are used to illustrate different options for prescribing OC and HRT in the real-word. The aim is to offer discussion topics that could be helpful to guide the choice of different hormonal treatments over a woman's lifetime and in the presence of risk factors.

RESULTS

We describe physio-pathological changes occurring during the administration of hormonal therapies. Furthermore, we analyze the risk of venous and arterial thrombosis associated with different products, routes of administration and additional risk factors. New hormonal preparations, such as estradiol combined with dienogest, as well as non-oral hormonal therapies, are suggested to decrease thrombotic risk significantly.

DISCUSSION

The availability of many products and different routes of administration allow most women to safely use contraception, as well as HRT. We encourage careful counselling instead of inflexible or fearful behavior, as expanding options and choices will allow women to make the best decisions for their health.

Living on Oral Anticoagulants: Duke Anticoagulation Satisfaction Scale Results

BACKGROUND

Direct oral anticoagulants (DOACs) are widely used in patients with atrial fibrillation and venous thromboembolism. The lack of the need for laboratory monitoring and a better safety than vitamin K antagonists (VKAs) has probably changed the quality of life of patients on these oral anticoagulants. This was a real-life prospective observational cohort study. The aim was to evaluate if a long-term treatment with DOACs could offer a better quality of life than VKAs. Moreover, age, gender, education level, time in therapeutic range for VKAs, taking medication once or twice a day for DOACs, the total daily number of medications and thrombotic and bleeding complications were considered as variables probably associated with the quality of life of these patients.

METHODS

Between January and December 2021, the Duke Anticoagulation Satisfaction Scale (DASS) 25-items was administered as an interview to patients on either VKAs or DOACs therapy. During the follow-up period, all of the patients were closely monitored to evaluate possible bleeding and thrombotic events.

RESULTS

The analysis included 300 outpatients treated with VKAs and 254 treated with DOACs. In general, the quality of life was better in patients taking DOACs (DASS total score: DOACs = 44.7, 42.9-46.5 vs. VKAs = 51, 49.2-52.8, p < 0.0001) as the daily-life limitations, hassles and burdens and the psychological impact were less important than in patients on VKAs therapy.

CONCLUSIONS

VKAs negatively influence the daily-life of the patients in terms of both less satisfaction and time-consuming tasks. DOACs confer a better quality of life even if some concerns emerge from not knowing how their therapy is working.

A journey to vasculopathy in systemic sclerosis: focus on haemostasis and thrombosis

Systemic sclerosis is a multisystem connective tissue disease, characterized by endothelial autoimmune activation, along with tissue and vascular fibrosis leading to vasculopathy and to a progressive loss of angiogenesis. This condition further deranges the endothelial barrier favouring the opening of the endothelial junctions allowing the vascular leak in the surrounding tissues: this process may induce cell detachment which allows the contact between platelets and collagen present in the exposed subendothelial layer. Platelets first adhere to collagen via glycoprotein VI and then, immediately aggregate because of the release of von Willebrand factor which is a strong activator of platelet aggregation. Activated platelets exert their procoagulant activity, exposing on their membrane phospholipids and phosphatidylserine, enabling the adsorption of clotting factors ready to form thrombin which in turn drives the amplification of the coagulative cascade. An essential role in the activation of blood coagulation is the tissue factor (TF), which triggers blood coagulation. The TF is found abundantly in the subendothelial collagen and is also expressed by fibroblasts providing a haemostatic covering layer ready to activate coagulation when the endothelial injury occurs. The aim of this review is to focus the attention on the underlying mechanisms related to haemostasis and thrombosis pathophysiology which may have a relevant role in SSc as well as on a possible role of anticoagulation in this disease.

Trace Metals and The Hemostatic System

In this narrative review we report the main relationships between trace metals and the hemostatic system since this aspect has seldom attracted the attention of the scientific community. A basic aspect to be considered is the importance of maintaining the fine control of all trace metals' levels since they have an important impact on the pathophysiology of the hemostatic system. It is worth noting that poor diet habits are responsible for most trace metal deficiencies, while pollution is responsible for dangerous exposure to them with a consequent negative impact on the general population. This appears of paramount importance in planning the implementation of food and nutrient support to ameliorate the hidden hunger and the quality of life of people especially in developing countries and limiting poisons both in the air and food. As it often happens, when damage to certain mechanisms takes a very long time to appear, no attention is paid to the importance of a systematic prevention to avoid late negative outcomes.

Chronic spontaneous urticaria: a low-grade disseminated intravascular coagulation only partially reversed by Omalizumab

Chronic spontaneous urticaria (CSU) is a disorder characterized by wheals and/or angioedema. The coagulation cascade and inflammation pathways are closely linked together. The aim of our study was first to investigate the dynamics of clot formation in plasma (Clot Waveform Analysis, CWA) in a group of 47 patients with CSU along with other coagulative parameters dedicated to the study of hypercoagulability, such as D-Dimer, F 1 + 2 peptide, Fibrinogen, Platelet count and Mean Platelet Volume (MPV). Secondly, 23 out of 47 patients were treated with Omalizumab at four administration intervals from T0 to T4. A statistically significant increase in Activated Partial Thromboplastin (aPTT) ratio, D-Dimer, F1 + 2, Platelet count and MPV was found when compared with 53 healthy controls (HC). In contrast, the 2nd Derivative of aPTT showed lower values than those of the HC. No differences were found between 1st derivative of aPTT and Fibrinogen. D-Dimer only showed a significant difference between T0 and T3. An activation of both coagulation and fibrinolysis along with a weaker clot acceleration may be in agreement with a low-grade DIC. The accelerated turnover of platelets expressed by both an increase in platelet count and MPV further supports this pathway in CSU. Omalizumab does not affect the relationship between the immune and the hemostatic systems.

Performance and Interpretation of Clot Waveform Analysis

The prothrombin time (PT) and the activated partial thromboplastin time (aPTT) are two basic tests for routine purposes, which are widely used in the clinical screening of coagulopathies. PT and aPTT are useful tests for detecting both symptomatic (hemorrhagic) and asymptomatic defects, but they are unsuitable for studying hypercoagulable states. However, these tests are available for studying the dynamic process of clot formation by means of the detection of the clot waveform analysis (CWA), which has been introduced several years ago. CWA can provide useful information on both hypocoagulable and hypercoagulable states. Nowadays it is possible to detect the whole clot formation both in the PT and aPTT tubes starting from the initial step of fibrin polymerization by means of specific and dedicated algorithm implemented in a coagulometer. In particular, CWA provides information on the velocity (first derivative), acceleration (second derivative), and density (delta) of clot formation. CWA has been applied to several pathologic conditions such as coagulation factor deficiency (including congenital hemophilia from factor VIII, IX, or XI deficiency), acquired hemophilia, disseminated intravascular coagulation (DIC), sepsis, replacement therapy management, chronic spontaneous urticarial, and liver cirrhosis, in patients with high venous thromboembolic risk before LMWH prophylaxis, and in patients with different hemorrhagic patterns along with an electron microscopy evaluation of the clot density. We report here materials and methods used for detecting the additional clotting parameters available in both PT and aPTT.

The ART of Thromboprophylaxis in the Prevention of Gestational Venous Thromboembolism

Assisted reproductive techniques (ART) allow infertile couples to conceive. Use of hormones to obtain a controlled ovarian stimulation and an adequate growth of the endometrium preparatory for embryo implantation are not riskless. Among others, thrombotic events can occur during the ovulation induction or pregnancy following ART. As the number of women approaching ART to conceive is steadily increasing, the issue of thrombotic risk in this setting is relevant. Data on the weight of each risk factor and on potential benefit of thromboprophylaxis are largely lacking. In this review, we discuss risk of venous thromboembolism during pregnancy following ART, with a focus on general (i.e.: age, body mass index, thrombophilia, bed rest, transfusions) and ART-specific (i.e., polycystic ovarian syndrome, ovarian hyperstimulation syndrome) risk factors. We also attempt to provide some suggestions to guide clinical practice, based on available data and studies performed outside ART.

Scanning electron microscopy of lung disease due to COVID-19 - a case report and a review of the literature

OBJECTIVE

The ongoing Coronavirus pandemic (COVID-19) showed similar characteristics with the severe acute respiratory syndrome (SARS). In the most compromised cases, COVID-19 infection leads to death due to severe respiratory complications. COVID-19-related acute respiratory distress syndrome (ARDS) is the primary cause of death in these patients. In the present study, we show an ultrastructural analysis on the lungs of a patient affected by COVID-19.

PATIENTS AND METHODS

Lung specimens obtained at autopsy from a 63-years old patient affected by COVID-19 were fixed in 1% paraformaldehyde. Slices of 300 µm thickness were dehydrated and dried by Critical Point Drying in CO2. Slices were covered with a conductive gold film approximately 30 nm thick and observed at a Zeiss Sigma 300 SEM FEG in the secondary electron (SE) and backscattered electron (BSE) modes. As case control a lung biopsy from a 60-year-old man was considered.

RESULTS

At low power in all COVID-19 lung specimens severe changes in the pulmonary architecture were found, due to the collapse of air spaces. Moreover, alveolar cavities were covered by large membranes. At high power, alveolar membranes showed a fibrillar structure, suggestive of a loose network of fibrin. It has been also found that intra-alveolar red blood cells were frequently present in the alveolar spaces, surrounded by a reticular fibrin network, suggestive for fibrin-hemorrhagic alveolitis. Alveolar changes were constantly associated with pathological features related to the pulmonary vessels. Vascular changes were prominent, including endothelial damage and thrombosis of large pulmonary vessels. Fibrinous microthrombi were frequently detected in the inter-alveolar septal capillaries. In addition, it has been frequently detected capillary proliferation in the alveolar septa with finding suggestive for intussusceptive neo-angiogenesis.

CONCLUSIONS

In conclusion, our electron microscopy analysis showed that COVID-19-related lung disease is characterized by a substantial architectural distortion, with the interactions between alveolar and vascular changes. Intra-alveolar hyaline membranes are associated with macro- and micro-thrombotic angiopathy, ending with capillary proliferation. The new blood vessel formation originates from the septa and extends into the surrounding parenchyma. Our findings confirm previous reports on the specificity of the multiple and complex morphological pattern typical, and apparently specific, of COVID-19-related lung disease.

Ultrastructural findings of lung injury due to Vaccine-induced Immune Thrombotic Thrombo- cytopenia (VITT) following COVID-19 vaccination: a scanning electron microscopic study

Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a rare new syndrome occurring after the ChAdOx1 nCoV-19 vaccine immunization. Patients with VITT are characterized by a variable clinical presentation, likewise also the outcome of these patients is very variable. Here we report the lung ultrastructural findings in the course of VITT of a 58-year-old male patient. Alveoli were mainly dilated, irregular in shape, and occupied by a reticular network of fibrin, while interalveolar septa appeared thickened. The proliferation of small capillaries gave rise to plexiform structures and pulmonary capillary hemangiomatosis-like features. Near the alveoli occupied by a dense fibrin network, the medium-sized arteries showed a modified wall and an intraluminal thrombus. This scenario looks quite similar to that found during COVID-19, where the lungs suffer from the attack of the antigen-antibodies complexes and the virus respectively. In both diseases, the final outcome is a severe inflammation, activation of the haemostatic system and fibrinolysis.

Management of DOAC in patients undergoing planned surgery or invasive procedure: FCSA position paper

Patients on anticoagulant treatment are constantly increasing, with an estimated prevalence in Italy of 2% of the total population. About a quarter of the anticoagulated patients require temporary cessation of direct oral anticoagulants (DOACs) or vitamin K antagonists for a planned intervention within 2 years from anticoagulation inception. Several clinical issues about DOAC interruption remain unanswered: many questions are tentatively addressed daily by thousands of physicians worldwide through an experience-based balancing of thrombotic and bleeding risks. Among possible valuable answers, the Italian Federation of Centers for the diagnosis of thrombotic disorders and the Surveillance of the Antithrombotic therapies (FCSA) proposes some experience-based suggestions and expert opinions. In particular, FCSA provides practical guidance on the following issues: (1) multiparametric assessment of thrombotic and bleeding risks based on patients' individual and surgical risk factor, (2) testing of prothrombin time, activated partial thromboplastin time, and DOAC plasma levels before surgery or invasive procedure, (3) use of heparin, (4) restarting of full-dose DOAC after high risk bleeding surgery, (5) practical nonpharmacological suggestions to manage patients perioperatively. Finally, FCSA suggests creating a multidisciplinary “anticoagulation team” with the aim to define the optimal perioperative management of anticoagulation.

Fetal programming of atherosclerosis: may the barker hypothesis explain the susceptibility of a subset of patients to develop stroke or cardiac infarct?

The risk stratification of young adults between subjects who will develop a mild form of atherosclerosis and subjects who will undergo a severe disease remains inaccurate. In the eighties of the previous century, David JP Barker has demonstrated the relationship between fetal conditions and occurrence of pathologies in adulthood. In this paper, the multiple evidence that might explain the increased susceptibility to severe forms of atherosclerosis, including stroke and cardiac infarct, in subjects who underwent intrauterine growth restriction (IUGR) will be analyzed. Specifically, we will review those inter-connected data indicating an association between a low weight at birth and an adult phenotype which might favor a severe outcome of atherosclerosis. Young and adult subjects born too small (IUGR) or too early (pre-terms) might represent a subgroup of "at risk subjects", more susceptible toward severe forms of atherosclerosis. Given that low birth weight (LBW) may be considered a surrogate of IUGR, this phenotypic feature could be considered among those indispensable clinical data collected in every patient presenting with atherosclerosis, irrespectively of age. According to the hypothesis that structural arterial changes might represent the link between LBW and susceptibility to atherosclerosis later in life, we suggest that the prevention of atherosclerosis should begin at birth. Regenerative and physiological substances such as thymosin Beta-4 could be challenged for a new "arterial regenerative medicine" in the perinatal period. The goal of this new approach should be the reinforcement of the structure of the arterial wall, allowing LBW newborns to avoid the most severe complications of atherosclerosis later in life: a dream that our research could contribute to bringing to life.

Aortic vulnerability to COVID-19: is the microvasculature of vasa vasorum a key factor? A case report and a review of the literature

Arterial thromboembolic complications reported in patients with COVID-19 infection suggested that SARS-CoV-2 can trigger atherosclerotic plaque vulnerability. While endothelial cells in healthy subjects protect against thrombus formation, after injury they show prothrombotic activity. In addition, it has been hypothesized that "cytokine storm" might stimulate the production of neo-platelets triggering an abnormal "immunothrombosis" responsible for the hypercoagulable state induced in COVID-19 patients. The aim of this study is to report a case of severe COVID-19 infection characterized by the occurrence of microthrombosis in the vasa vasorum of the aorta. A 67-year-old male patient, in good health status and without comorbidities, who underwent a severe COVID-19 infection with fatal outcome, showed scattered aortic atherosclerotic plaques, characterized by multiple occlusive micro-thromboses in the vasa vasorum, spread out lymphocytic infiltrates and foci of endotheliitis and endothelial detachment. This case report confirms the previously described thrombotic involvement of vasa vasorum in COVID-19. The occurrence of the synchronous damage involving both the lumen surface (endothelial dysfunction, endotheliitis and endothelial detachment) and the adventitia (inflammation and occlusive thrombosis of vasa vasorum) could be the key points related to the fatal outcome of the SARS-CoV-2 patients. In our opinion, vasa vasorum thrombosis may thus initiate an atherogenic process that could be characterized by a much more rapid development.

Thrombotic sinusoiditis and local diffuse intrasinusoidal coagulation in the liver of subjects affected by COVID-19: the evidence from histology and scanning electron microscopy

OBJECTIVE

Liver injury has been reported in patients with COVID-19. This condition is characterized by severe outcome and could be related with the ability of SARS-CoV-2 to activate cytotoxic T cells. The purpose of this study is to show the histological and scanning electron microscopy features of liver involvement in COVID-19 to characterize the liver changes caused by the activation of multiple molecular pathways following this infection.

PATIENTS AND METHODS

Liver biopsies from 4 patients (3 post-mortems and 1 in vivo) with COVID-19 were analyzed with histology and by scanning electron microscopy.

RESULTS

The liver changes showed significant heterogeneity. The first case showed ground glass hepatocytes and scattered fibrin aggregates in the sinusoidal lumen. The second evidenced intra-sinusoidal thrombi. The third was characterized by sinusoidal dilatation, atrophy of hepatocytes, Disse's spaces dilatation and intra-sinusoidal aggregates of fibrin and red blood cells. The fourth case exhibited diffuse fibrin aggregates in the dilated Disse spaces and microthrombi in the sinusoidal lumen.

CONCLUSIONS

In COVID-19-related liver injury, a large spectrum of pathological changes was observed. The most peculiar features were very mild inflammation, intra-sinusoidal changes, including sinusoidal dilatation, thrombotic sinusoiditis and diffuse intra-sinusoidal fibrin deposition. These findings suggested that a thrombotic sinusoiditis followed by a local diffuse intra-vascular (intra-sinusoidal) coagulation could be the typical features of the SARS-CoV-2-related liver injury.

Fetal programming of COVID-19: may the barker hypothesis explain the susceptibility of a subset of young adults to develop severe disease?

The risk stratification of young adults between subjects who will develop a mild form COVID-19 and subjects who will undergo a severe disease remains inaccurate. In this review, we propose that the Barker hypothesis might explain the increased susceptibility to severe forms of COVID-19 in subjects who underwent intrauterine growth restriction (IUGR). In this paper evidence indicating an association between a low birth weight and an adult phenotype which might favor a severe outcome of SARS-CoV-2 infection are presented: lower lung functional capacity; increased respiratory morbidity; changes in fibrinogen and Factor VII serum levels and dysregulation of the hemostasis and thrombosis system; acquisition of a pro-thrombotic phenotype; low nephron number, with decreased ability to sustain renal function and increased renal morbidity; heart remodeling, with a less efficient cardiac function; endothelial dysfunction, a risk factor for the insurgence of the multiple organ failure; remodeling of arteries, with changes in the elastic properties of the arterial wall, predisposing to the insurgence and progression of atherosclerosis; dysfunction of the innate immune system, a risk factor for immune diseases in adulthood. These data suggest that young and adult subjects born too small (IUGR) or too early (pre-terms) might represent a subgroup of "at risk subjects", more susceptible toward severe forms of COVID-19. Given that LBW may be considered a surrogate of IUGR, this phenotypic marker should be included among the indispensable clinical data collected in every patient presenting with SARS-COV-2 infection, irrespectively of his/her age.

Chronic intravascular coagulation in liver cirrhosis predicts a high hemorrhagic risk

OBJECTIVE

In liver cirrhosis, a complex coagulopathy does exist. The aim was to investigate whether a possible chronic consumption coagulopathy is the underlying phenomenon of the disease.

PATIENTS AND METHODS

We measured endogenous thrombin generation with and without thrombomodulin (ETP ratio) along with D-Dimer in a group of consecutive 282 cirrhotic patients. Fibrinogen, Platelet count and the Hemorrhagic score were previously computed in the same patients. The ETP ratio represents the resistance to the anticoagulant activity of TM and should be considered as an index of a procoagulant imbalance.

RESULTS

ETP ratio and D-Dimer showed higher values in the cirrhotic patients when compared to controls thus showing a hypercoagulable state. When the patients were divided based on the Hemorrhagic score >7, we found that Fibrinogen, ETP ratio, D-Dimer and the platelet count were significantly different between the two groups. Again, when we considered ETP ratio >0.88, the median value of the cirrhotic patients, all parameters, were statistically different between the two groups. D-Dimer were higher while fibrinogen and platelet count were statistically lower in cirrhotic patients with higher ETP ratio values. Even when the same patients were divided based on their platelet count (</> 100 x 109/L) the results showed a similar behavior. ROC curves showed significant AUCs when the hemorrhagic score was challenged against Fibrinogen, D-Dimer, Platelet count and ETP ratio.

CONCLUSIONS

In liver cirrhosis hypercoagulable state is associated with an increase in D-Dimer levels along with a decrease in fibrinogen and platelet count thus indicating a low-grade intravascular coagulation which predicts a high hemorrhagic risk.

Vaccine-induced severe thrombotic thrombocytopenia following COVID-19 vaccination: a report of an autoptic case and review of the literature

OBJECTIVE

Vaccine-induced immune thrombocytopenia (VITT) is a new syndrome occurring primarily in healthy young adults, with a female predominance, after receiving the first dose of ChAdOx1 nCoV-19 vaccine. We describe VITT syndrome characterized by severe thrombosis and thrombocytopenia found in our patient, with fatal outcome.

CASE REPORT

A 58-year-old man, after 13 days from the first administration of ChAdOx1 nCoV-19 vaccine (AstraZeneca), presented with abdominal pain, diarrhea and vomitus. Laboratory tests revealed a severe thrombocytopenia, low fibrinogen serum levels and marked increase of D-dimer serum levels. The patient quickly developed a multiple organ failure, till death, three days after the hospital admission.

RESULTS

At histology, in the lungs, interalveolar septa appeared thickened with microthrombi in the capillaries and veins. Interalveolar septa appeared thickened and showed vascular proliferation. Thrombi were detected in the capillaries of glomerular tufts. In the hearth, thrombi were observed in veins and capillaries. In the liver, voluminous fibrin thrombi were diffusely observed in the branches of the portal vein. Microthrombi were also found in the vasa vasorum of the wall of abdominal aorta. In the brain, microthrombi were observed in the capillaries of the choroid plexuses. Diffuse hemorrhagic necrosis was observed in the intestinal wall with marked congestion of the venous vessels.

CONCLUSIONS

In our patient, the majority of data necessary for a VITT final diagnosis were present: thrombocytopenia and thrombosis in pulmonary, portal, hepatic, renal and mesenteric veins, associated with a marked increase of D-dimer serum levels. The finding of cerebral thrombosis in choroid plexuses, is a new finding in VITT. These features are suggestive for a very aggressive form of VITT.

Findings from a multicentre, observational study on reproductive outcomes in women with unexplained recurrent pregnancy loss: the OTTILIA registry

STUDY QUESTION

What evaluation and care is offered to women after unexplained recurrent pregnancy loss (RPL) or intra-uterine foetal death (IUFD) and what are the reproductive outcomes?

SUMMARY ANSWER

Women are assessed for thrombophilia and often treated with low-molecular weight heparin (LMWH) and/or low-dose aspirin (ASA).

WHAT IS KNOWN ALREADY

Randomized controlled trials (RCTs) on possible efficacy of heparins and/or aspirin have been inconclusive due to limited power to detect a difference and patient heterogeneity.

STUDY DESIGN, SIZE, DURATION

Prospective multicentre cohort study performed in 12 hospitals in three countries between 2012 and 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All consecutive pregnant women with recurrent PL (≥3 losses or 2 losses in the presence of at least one euploid foetal karyotype) or at least one IUFD. Eligible women may have undergone thrombophilia testing before conception, at the discretion of local providers. The possible assignment of women to treatments (such as LMWH) was not decided a priori but was determined based on the responsible provider's current practice. Aims of the study were: (i) to evaluate factors associated with pregnancy outcome; (ii) to compare clinical management strategies in women with and without a subsequent successful pregnancy; and (iii) to evaluate characteristics of women who may benefit from antithrombotic therapy. A propensity score matching method was used to balance the differences in baseline characteristics.

MAIN RESULTS AND THE ROLE OF CHANCE

A matched sample of 265 pregnant women was analysed, with all undergoing thrombophilia screening; 103 out of 119 (86.6%) with and 98/146 (67.1%) without thrombophilia were prescribed with LMWH and/or ASA. Overall, live-births were recorded in 204 cases (77%), PL or IUFD in 61 (23%) pregnancies. Logistic regression showed a significant interaction between thrombophilia and treatment with LMWH (P = 0.03). Findings from sensitivity analysis showed odds ratio (OR) for pregnancy loss in women with inherited or acquired thrombophilia in absence of any treatment was 2.9 (95% CI, 1.4-6.1); the administration of LMWH (with or without ASA) was associated with higher odds of live-birth (OR, 10.6; 95% CI, 5.0-22.3). Furthermore, in women without thrombophilia, the odds of live-birth was significantly and independently associated with LMWH prophylaxis (alone or in association with ASA) (OR, 3.6; 95% CI, 1.7-7.9).

LIMITATIONS, REASONS FOR CAUTION

While the propensity score matching allows us to balance the differences in baseline characteristics, it does not eliminate all confounding.

WIDER IMPLICATIONS OF THE FINDINGS

Antithrombotic prophylaxis during pregnancy may be effective in women with otherwise unexplained PL or IUFD, and even more useful in those with thrombophilia.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by Italian Ministry of Health (Ricerca Corrente 2018-2020). Dr G.P. has received research grant support from Bristol Myers Squibb/Pfizer Alliance, Janssen, Boston Scientific Corporation, Bayer, and Portola and consultant fees from Amgen and Agile Therapeutics. Dr E.G. has received consultant fees from Italfarmaco and Sanofi. All other authors declare that they have no conflict of interest.

TRIAL REGISTRATION NUMBER

NCT02385461.

Clinical history and gastrointestinal bleeding in patients taking oral anticoagulants

BACKGROUND

Common risk factors for gastrointestinal bleeding (GIB) are advanced age and the use of antiplatelet or anticoagulants drugs for the prevention of cardiovascular diseases.

METHODS

In this prospective real-world observational study, oral anticoagulated patients were recruited and followed between June 2013 and December 2019. The primary end-point was to evaluate a possible relationship between bleeding events and patients' clinical history of gastrointestinal disease prior to the start of the therapy. The secondary end-points were time of GIB appearance and the percentage of idiopathic or provoked events, i.e., bleeding due to a gastrointestinal disease. In case of GIB event all the patients were studied by means of endoscopic procedures. Cox regression was used to calculate the relative hazard ratios (HRs) of GIB for each considered clinical variable.

RESULTS

734 patients on both VKAs or DOACs were studied. Overall, 46 hemorrhagic events were recorded: 6 were major bleeding (0.42/100 patient-years) while 43 were clinically relevant non major bleeding (2.8/100 patient-years). The Cox regression analysis did not show any relationships among GIB and the variables considered.

CONCLUSION

The patients' clinical history is neither a predictor for GIB bleeding nor a guide to the choice of the oral anticoagulant to be administered. Routinely applying bleeding risk screening, such as occult blood in the stool, should be added to the periodic laboratory checks for early recognition of patients at higher risk of GIB.

Infectious agents including COVID-19 and the involvement of blood coagulation and fibrinolysis. A narrative review

OBJECTIVE

Platelets, blood coagulation along with fibrinolysis are greatly involved in the pathophysiology of infectious diseases induced by bacteria, parasites and virus. This phenomenon is not surprising since both the innate immunity and the hemostatic systems are two ancestral mechanisms which closely cooperate favoring host's defense against foreign invaders. However, the excessive response of these systems may be dangerous for the host itself.

MATERIALS AND METHODS

We searched and retrieved the articles, using the following electronic database: MedLine and Embase. We limited our search to articles published in English, but no restrictions in terms of article type, publication year, and geography were adopted.

RESULTS

The hemostatic phenotype of the infectious diseases is variable depending on the points of attack of the different involved pathogens. Infectious diseases which show a prothrombotic phenotype are bacterial sepsis, SARS-CoV-2 and malaria. However, among the bacterial sepsis, Yersinia Pestis is characterized by a profibrinolytic behavior. On the contrary, the hemorrhagic fevers, due to Dengue and Ebola virus, mainly exploit the activation of fibrinolysis secondary to a huge endothelial damage which can release a large amount of t-PA in the early phase of the diseases.

CONCLUSIONS

Blood coagulation and fibrinolysis are greatly activated based on the strategy of the different infectious agents which exploit the excess of response of both systems to achieve the greatest possible virulence.

Clot characterization by multidisciplinary approach: biochemical and imaging parameters in a hypocoagulative setting. A pilot study

Background

Clot characterization is, to the present days, a multimodal approach: scanning the clot by electron microscopy (SEM) is helpful for the visualization of fibrin structure along with laboratory parameters such as the clot waveform analysis (CWA) and thrombin generation in different settings of clot abnormalities. This study aimed to assess whether the coagulative parameters were consistent with the clot images texture acquired by SEM, and therefore to propose a more generalist and integrative approach to clots classification.

Design and methods

In this pilot study, the examined population consists of eight healthy subjects, seven patients affected by Acquired Hemophilia A (AHA) and seven patients treated with Vitamin K Antagonists (VKAs), similar for age and gender. We studied the velocity and acceleration (1^st and 2^nd derivative of the aPTT) of clot formation (CWA), the thrombin generation, and the clots’ scanning by SEM. Images acquired with SEM were then analyzed with the MATLAB software with the “Texture Analysis” methods to perform classification. Among the various texture parameters, we reported Contrast and Energy.

Results

Significant differences among healthy subjects, patients with AHA and those treated with VKAs were detected for the coagulative parameters. We found no differences between VKAs and AHA patients. Contrast and energy highlighted a significant difference among the three groups in agreement with the laboratory's parameters. We found no significant differences between VKAs and AHA patients.

Conclusions

The use of SEM, CWA and thrombin generation parameters may be a starting point for studies aimed to demonstrate the general characteristics of clot formation in different clinical conditions with a multiparametric approach.

Heparins and 2019-nCoV infection: a narrative review

OBJECTIVE

Patients with 2019-nCoV infection have a high risk to develop venous thrombotic events. Several guidelines recommend the use of either unfractionated heparin or low molecular weight heparins in preventing thrombotic events in these patients. However, results from clinical studies, so far published, reached controversial conclusions on heparin efficacy in this kind of patients since the incidence of venous thromboembolism remains high despite prophylaxis. This narrative review aims to provide an overview of the antiviral and anti-inflammatory properties of heparins and their efficacy and safety in SARS-CoV-2 medical ward-patients. Moreover, anatomical findings and ongoing trials are also reported. Finally, this narrative review tries to explain why heparins fail to prevent venous thrombosis.

MATERIALS AND METHODS

We searched for the most relevant published studies on heparins and 2019-nCoV infected patients using the MEDLINE electronic database in the period between January and December 2020. Articles were preliminarily defined as eligible if they: a) were in English language, b) enrolled 250 or more medical ward-patients and 100 or more ICU-patients, c) reported results on patients treated with heparins in a percentage of at least 70% and d) performed an objectively confirmed diagnosis of VTE.

RESULTS

Data from medium to large scientific studies show that the incidence of venous thrombotic events in medical ward-patients with SARS-CoV-2 vary between 0% and 8.3%, while this rate is higher, from 6.2% to 49%, in Intensive Care Unit-patients. However, heparins reduce the mortality rate in these patients of about 50%. Histological findings show that thrombosis could affect capillaries, main and small-mid-sized vessels, and it is associated with diffuse alveolar damage.

CONCLUSIONS

Heparins have anti-inflammatory and anti-viral properties, which may be of help in reducing mortality in SARS-CoV-2 patients. Failure of heparins at prophylactic dosages in preventing VTE, especially in ICU-patients, could be due to the severity of the disease. Data on the use of heparins in an early phase of the 2019-nCoV infection are still lacking.

Trial of Rivaroxaban in AntiPhospholipid Syndrome (TRAPS): Two-year outcomes after the study closure

BACKGROUND

Trial of Rivaroxaban in AntiPhospholipid Syndrome was a prospective randomized, open-label, noninferiority study conducted in 14 centers in Italy. Rivaroxaban was compared with warfarin for the prevention of thromboembolic events, major bleeding, and vascular death in high-risk, triple-positive patients with antiphospholipid syndrome.

OBJECTIVE

The aim of this paper is to report the events during the 2-year follow-up after the study closure.

METHODS

On January 28, 2018, the trial was prematurely stopped by adjudication and safety committee for an excess of events in the rivaroxaban group. Randomized patients were advised on trial results and those randomized to rivaroxaban were solicited to switch to warfarin. All 14 participating centers were asked and accepted to follow their patients for clinical events. This report describes the rate of events that occurred between January 28, 2018, and January 28, 2020.

RESULTS

Of 120 randomized patients, 115 were available for follow-up. Outcome events were two in six (33.3%) patients who remained on direct oral anticoagulants (DOACs) and six in 109 (5.7%) patients on warfarin (hazard ratio [HR] 6.9; 95% confidence interval [CI] 1.4-34.5, P = .018). The two patients on DOACs (one taking dabigatran and one taking rivaroxaban) suffered from thromboembolic events, whereas of the six patients with composite outcomes on warfarin, three had thromboembolic events (HR for thrombosis 13.3; 95% CI 2.2-79.9, P = .005).

CONCLUSION

These data further support the use of warfarin in high-risk patients with antiphospholipid syndrome.

Molecular pathways triggered by COVID-19 in different organs: ACE2 receptor-expressing cells under attack? A review

OBJECTIVE

In human pathology, SARS-CoV-2 utilizes multiple molecular pathways to determine structural and biochemical changes within the different organs and cell types. The clinical picture of patients with COVID-19 is characterized by a very large spectrum. The reason for this variability has not been clarified yet, causing the inability to make a prognosis on the evolution of the disease.

MATERIALS AND METHODS

PubMed search was performed focusing on the role of ACE 2 receptors in allowing the viral entry into cells, the role of ACE 2 downregulation in triggering the tissue pathology or in accelerating previous disease states, the role of increased levels of Angiotensin II in determining endothelial dysfunction and the enhanced vascular permeability, the role of the dysregulation of the renin angiotensin system in COVID-19 and the role of cytokine storm.

RESULTS

The pathological changes induced by SARS-CoV-2 infection in the different organs, the correlations between the single cell types targeted by the virus in the different human organs and the clinical consequences, COVID-19 chronic pathologies in liver fibrosis, cardiac fibrosis and atrial arrhythmias, glomerulosclerosis and pulmonary fibrosis, due to the systemic fibroblast activation induced by angiotensin II are discussed.

CONCLUSIONS

The main pathways involved showed different pathological changes in multiple tissues and the different clinical presentations. Even if ACE2 is the main receptor of SARS-CoV-2 and the main entry point into cells for the virus, ACE2 expression does not always explain the observed marked inter-individual variability in clinical presentation and outcome, evidencing the complexity of this disorder. The proper interpretation of the growing data available might allow to better classifying COVID-19 in human pathology.

Thrombosis centres and AVKs monitoring in COVID-19 pandemic

Vitamin K-Antagonists (VKAs) are the treatment of choice in patients with indications other than atrial fibrillation and venous thromboembolism. Moreover, some patients still assume VKAs refusing to change their therapy when direct oral anticoagulants (DOACs) are properly indicated. The COVID-19 pandemic has completely changed our lives, nullifying inter-personal relationships to avoid contagion, making difficult the VKAs monitoring. We describe the re-organization of our thrombosis centre (TC) as an example on how to face the emergency due to the COVID-19 pandemic. In the first phase, to avoid overcrowding at the TC, we planned to increase the interval time between INRs checks and to encourage blood sampling at home, especially for elderly patients. Moreover, precise scheduled blood sampling was also organized while telephone and email counselling were guaranteed by two doctors of the TC. In the second phase, to reduce the number of patients who daily attended our TC a switch from VKAs to DOACs was carried out, if no contraindications were identified. In the third phase, to protect patients, healthcare staff and hospital from COVID-19 widespread, telemedicine was strengthened. We tried to extend self-testing at home by means of portable coagulometers to as more patients as possible. To avoid patients staying or coming back to the TC an ad hoc web platform for sending the therapeutic dose adjustment and the next scheduled appointment was developed. The TC re-organization allowed us to monitor anticoagulated patients respecting personal isolation and security measures to avoid possible COVID-19 contagion.

Anticoagulation resumption after intracranial hemorrhage in patients treated with VKA and DOACs

BACKGROUND

Intracranial hemorrhage (ICH) is associated with severe prognosis and recurrent risk. This impacts on the decision to resume anticoagulation in atrial fibrillation (AF) or venous thromboembolism (VTE) patients. Purpose of our study is to evaluate the incidence rate of recurrent ICH in patients with AF or VTE resuming anticoagulation after a first ICH episode.

METHODS

We report data of two cohorts of AF or VTE after a first ICH. The Vitamin K antagonist (VKA) cohort (166 patients) derives from CHIRONE Study, the direct oral anticoagulant (DOAC) cohort (178 patients) derives from START2-Register RESULTS: The clinical characteristics of the two cohort are similar with the exception of more prevalence of history of previous stroke/TIA in DOAC patients with respect to VKA (p = 0.02) and serum creatinine levels>1.5 mg/dL in VKA patients with respect to DOAC(p = 0.0001). The index ICH was spontaneous in 66.4% and in 33.7% among DOAC and VKAs cohort respectively (p = 0.0001). During follow-up, 14 recurrent ICH were recorded; 9 (rate 2.5 × 100 patient-years) in VKA and 5 (rate 1.3 × 100 patient-years) in DOAC (Relative Risk 1.9; 95% CI 0.6-7.4; p = 0.2). The univariate logistic regression analysis showed that patients with recurrent ICH were more frequently males, hypertensive, with a history of previous Stroke/TIA and older than patients without recurrence. VKA patients showed a higher risk of recurrence with respect to DOAC patients (OR 1.9;95% CI 0.7-6.7).

CONCLUSIONS

A trend toward fewer ICH recurrences was detected among DOACs patients in comparison to the previously reported rate of patients on warfarin.

Managing anticoagulation in the COVID-19 era between lockdown and reopening phases

Patients on anticoagulant treatment are constantly increasing, with an estimated prevalence in Italy of 2% of the total population. The recent spreadout of the COVID-19 pandemic requires a re-organization of Anticoagulation Clinics to prevent person-to-person viral diffusion and continue to offer the highest possible quality of assistance to patients. In this paper, based on the Italian Federation of Anticoagulation Clinics statements, we offer some advice aimed at improving patient care during COVID-19 pandemic, with particular regard to the lockdown and reopening periods. We give practical guidance regarding the following points: (1) re-thinking the AC organization, (2) managing patients on anticoagulants when they become infected by the virus, (3) managing anticoagulation surveillance in non-infected patients during the lockdown period, and (4) organizing the activities during the reopening phases.

Managing anticoagulation in the COVID-19 era between lockdown and reopening phases

Patients on anticoagulant treatment are constantly increasing, with an estimated prevalence in Italy of 2% of the total population. The recent spreadout of the COVID-19 pandemic requires a re-organization of Anticoagulation Clinics to prevent person-to-person viral diffusion and continue to offer the highest possible quality of assistance to patients. In this paper, based on the Italian Federation of Anticoagulation Clinics statements, we offer some advice aimed at improving patient care during COVID-19 pandemic, with particular regard to the lockdown and reopening periods. We give practical guidance regarding the following points: (1) re-thinking the AC organization, (2) managing patients on anticoagulants when they become infected by the virus, (3) managing anticoagulation surveillance in non-infected patients during the lockdown period, and (4) organizing the activities during the reopening phases.

Position paper on the safety/efficacy profile of Direct Oral Anticoagulants in patients with Chronic Kidney Disease: Consensus document of Società Italiana di Nefrologia (SIN), Federazione Centri per la diagnosi della trombosi e la Sorveglianza delle terapie Antitrombotiche (FCSA) and Società Italiana per lo Studio dell'Emostasi e della Trombosi (SISET)

Direct oral anticoagulants (DOAC) are mostly prescribed to prevent cardioembolic stroke in patients with non-valvular atrial fibrillation (AF). An increasing number of guidelines recommend DOAC in AF patients with preserved renal function for the prevention of thromboembolism and an increased use of DOAC in daily practice is recorded also in elderly patients. Aging is associated with a reduction of glomerular filtration rate and impaired renal function, regardless of the cause, increases the risk of bleeding. Multiple medication use (polypharmacy) for treating superimposed co-morbidities is common in both elderly and chronic kidney disease (CKD) patients and drug-drug interaction may cause accumulation of DOAC, thereby increasing the risk of bleeding. There is uncertainty on the safety profile of DOAC in patients with CKD, particularly in those with severely impaired renal function or end stage renal disease, due to the heterogeneity of studies and the relative paucity of data. This document reports the position of three Italian scientific societies engaged in the management of patients with atrial fibrillation who are treated with DOAC and present with CKD.

The Repeatable Battery for the Assessment of Neuropsychological Status as a screening strategy for HIV-Associated Neurocognitive Disorders

HIV-infected people are at risk for neurocognitive impairment (HIV-Associated Neurocognitive Disorders - HAND). To evaluate whether the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), a widely used neurocognitive screening tool, could be a valid instrument for HAND identification, we evaluated 166 HIV-infected subjects. Our results showed that 96 (57.8%) HIV-infected scored RBANS Total Index Score <85 (at least one SD below the normal), 12 (7.2%) of them scored RBANS Total Index Score <70 (at least 2 SD below the normal, indicating a possible HIV-Associated Dementia). The more compromised areas were Immediate and Delayed Memory, and Attention. In the group with RBANS Total Index Score <85, there were significantly lower scores of Mini Mental State Examination (P = 0.0008), Clock Drawing Test (P = 0.0015) and higher score of Geriatric Depression Scale (P = 0.02) compared to the RBANS Total Index Score ≥85 group. Using a stepwise logistic regression, considering RBANS Total Index Score as dependent variable, we found a positive interaction with tenofovir/emtricitabine assumption (P = 0.027), Clock Drawing Test (P = 0.0125) and educational level (P = 0.0054). Being the viro-immunological markers not capable of predicting cognitive decline in HIV-infected individuals, our data suggest that RBANS may be a valid tool for the early identification of HIV-related cognitive impairment.

Pulmonary Thrombosis: A Clinical Pathological Entity Distinct from Pulmonary Embolism?

Since Virchow's autopsy studies in the mid-1800s, it has generally been believed that pulmonary embolism (PE) originated from the embolization of fibrin fragments from a deep venous thrombosis (DVT). However, a DVT is often not found in patients with PE (up to 50% of cases). Could fibrin form in the pulmonary vessels without coming from the periphery? In this review, the authors will try to support the hypothesis that a pulmonary thrombosis (PT) may develop. They will do so through different clinical models related to some pathological conditions such as pneumonia, chronic obstructive pulmonary disease (COPD), and asthma, all of which show a close relationship between local inflammation and activation of blood coagulation, two defensive systems that may lead to fibrin deposition in the lungs, thus recognizing the possibility that PT may be a newly recognized entity. An increased risk for PE has been demonstrated in these conditions. Sickle cell disease and assisted reproductive technologies are other very different conditions in which an increased risk for PE has been found. Gaucher's disease is a rare hereditary condition in which the hemostatic system could have a role in the pathogenesis of pulmonary hypertension, which complicates the course of the disease. In particular, the increased risk for PT, common to all these conditions, deserves attention when a patient presents with sudden dyspnea, an unexpected COPD exacerbation, or severe sudden asthmatic dyspnea. As a consequence, prediction scores for venous thromboembolism could be revised.

A Sardinian Family with Factor XI Deficiency

INTRODUCTION

 Factor XI (FXI) deficiency is a bleeding disorder which causes a bleeding tendency after trauma or surgery. An inhibitor may be acquired secondary to replacement therapy.

AIM

 To study on genetical and functional grounds a family admitted to our Haemostasis and Thrombosis Centre for an incidental finding of a prolonged activated partial thromboplastin time (aPTT) in three members.

METHODS

 aPTT mixing test, dosage of FXI activity and antigen, FXI inhibitor titration, DNA analysis and clot waveform analysis (CWA) were performed.

RESULTS

 Patients II.1, II.3 and II.4 showed a severe FXI deficiency (0.7, 0.7 and 1.8%, respectively) and low antigen level. Since the proposita was already treated with plasma, the dosage of the inhibitor was determined to be 6.4 Bethesda units. They were homozygous for the p.Glu117Stop mutation. The other family members were heterozygous. The velocity and the maximum acceleration of the clot formation were lower than those of the other family members and the normal subjects but higher than those of patients with acquired haemophilia A.

CONCLUSION

 A mixing test of a prolonged aPTT should be performed because it will be present both in patients with or without the inhibitor. A molecular analysis in severe FXI deficiency is warranted as it may have prognostic significance. CWA may be helpful for better understanding the pathophysiology of this kind of defect.

Prophylaxis of peripartum haemorrhage using recombinant factor VIIa (rfVIIa) in pregnant women with congenital factor VII deficiency: A case report and literature review

Congenital factor VII deficiency is a rare autosomal recessive disorder associated to different haemorrhagic manifestations. Labour and delivery may cause bleeding risk in patients with this coagulation deficit, thus it is appropriate to clarify whether prophylaxis of peripartum haemorrhage is necessary. To date, there are very few cases in scientific literature which report the management of women with congenital factor VII deficiency during labour, and a consensus for prophylaxis does not exist. In this manuscript we present the management of a 35 years old woman with factor VII deficiency, treated with recombinant factor VIIa before delivery, without haemorrhagic complications either for the woman and for the infant. Therefore, we present a review of similar cases managed with a peripartum prophylaxis with recombinant factor VIIa, and discuss its usefulness and effectiveness, in view of the severity of the deficit and the doses used.

Management of Patients Taking Oral Anticoagulants Who Need Urgent Surgery for Hip Fracture

The number of hip fractures in anticoagulated patients is predicted to increase, due to people living longer. However, evidence regarding urgent perioperative management of elderly patients with hip fracture who take oral anticoagulants (vitamin K antagonists or direct oral anticoagulants) is scarce. In this article, the authors present a narrative review of the evidence to date supporting the urgent management of hip fracture in anticoagulated elderly patients. They discuss the complexity of managing the high risk of procedure-related bleeding and, at the same time, the high risk of thromboembolism. The role of a bridging procedure and the best strategy of anticoagulation reversal are also reviewed. Further studies are required to improve the evidence in urgent surgery, especially in frail elderly patients.

The venous thromboembolic risk and the clot wave analysis: a useful relationship?

BACKGROUND

Hospitalized patients with acute medical conditions have higher venous thromboembolism (VTE) risk. A patient with a final Padua Prediction Score (PPS) of ≥4 is considered to be at high risk for VTE. The aim of this study was to investigate on a possible relationship between PPS, the dynamics of the clot formation, i.e. the clot waveform analysis (CWA) of aPTT, fibrinogen and D-Dimer in a large group of medical patients.

METHODS

CWA in terms of velocity (first derivative), acceleration (second derivative), density (Delta) of aPTT, fibrinogen, D-Dimer and PPS for VTE were determined in 801 medical patients divided in three groups (without antithrombotic prophylaxis and high PPS, without antithrombotic prophylaxis and low PPS, with antithrombotic prophylaxis and high PPS) and a group of healthy subjects.

RESULTS

CWA, fibrinogen and D-Dimer values were higher in the medical patients with high PPS with or without antithrombotic prophylaxis when compared with patients without antithrombotic prophylaxis with low PPS and healthy subjects. The second derivative, fibrinogen and D-Dimer were significantly associated with a high PPS score (≥4): odds ratio (OR) = 1.53, 95% confidence interval (CI) = 1.03-2.28; OR = 1.91, 95% CI = 1.3-2.79; OR = 3.16, 95% CI = 2.29-4.36, respectively. Interactions between first derivative and D-Dimer (OR = 2.14, 95% CI = 1.23-3.72) and first derivative and fibrinogen (OR = 1.75, 95% CI = 1.02-2.98) were found.

CONCLUSIONS

CWA could give useful information to recognize a hypercoagulable state in patients admitted to a medical ward with high and low PPS. First and second derivative aPTT, D-Dimer and fibrinogen levels could be added to PPS to better assess the global thromboembolic risk of these patients.

Direct oral anticoagulants: what can we learn?

Direct oral anticoagulants (DOACs) represent an innovation because they avoid periodic laboratory monitoring, and also reduce cerebral bleeding. An examination of the performance of DOACs versus warfarin in randomized clinical trials dedicated to atrial fibrillation would reveal the poor performance of warfarin because the percentage of major bleeding is always above 3%; however, the percentage of major bleeding is less than half of that when the management is done in anticoagulation clinics (ACs). Several years ago, a common opinion was that ACs would disappear as soon as DOACs enter the market. We proposed then that ACs could be transformed into thrombosis centres (TCs) because we envisaged many new activities in terms of diagnostic tools and therapeutic choices. After the introduction of DOACs, the role of the ACs has been re-evaluated because their role may be crucial in selecting both the most appropriate diagnostic approach and the best therapeutic option (including anti-vitamin K drugs) for the single patient. TCs can organize a regular follow-up to improve patient adherence to DOACs. Marketing might have a role in the decision making of the single doctor. Efforts should be made for limiting the relationships between doctors and pharmaceutical companies. It seems reasonable to better prepare doctors, during their university courses, for them to develop a greater scientific culture that would enable them to critically read clinical studies and acquire an independent opinion. Ideally, an expert in haemostasis and thrombosis should handle new and old anticoagulants.

Has time come for the use of direct oral anticoagulants in the extended prophylaxis of venous thromboembolism in acutely ill medical patients? No

Acutely ill hospitalized medical patients are at high risk of venous thromboembolism (VTE). Although thromboprophylaxis in these patients is recommended since 2004 by the American College of Chest Physicians, it is widely underused. The doubt as to whether or not to treat patients at high VTE risk after hospital discharge came from the knowledge that this risk may persist after the hospital admission period. Two meta-analyses comparing extended- versus short-duration prophylaxis are published. The results demonstrate an unfavorable balance between VTE prevention and incidence of major bleeding in patients assigned to extended-duration thromboprophylaxis. Only in the APEX study, betrixaban, a direct inhibitor of factor Xa, shows similar efficacy and safety compared to enoxaparin. However, while it is very promising, oral anticoagulant phase III studies and post-marketing registers are lacking. Moreover, betrixaban has a long half-life, an excretion in the gut by means of P-glycoprotein, and the lack of an antidote. These characteristics and the meta-analysis results prompt us to answer no to the extended thromboprophylaxis in hospitalized medical patients, at least now.

Risk of reoperation in bioprosthetic valve patients with indication for long-term anticoagulation. Results from the observational retrospective multicentre PLECTRUM study

Objective

Several factors should be considered when a prosthetic heart valve, bioprosthetic valve (BV) or mechanical valve is to be implanted: thrombogenicity, life expectancy and the risk of reoperation.

Methods

We conducted an observational retrospective multicentre study among Italian Thrombosis Centers on patients with BV on long-term vitamin K antagonist (VKA) treatment to evaluate the risk of reoperation and the rate of bleeding and thrombotic events.

Results

We analysed 612 patients (median age 71.8 years) with BV on long-term VKA treatment for the presence of atrial fibrillation (AF) (78.4%) or other indications (21.6%). Thirty-four major bleeding events (rate 1.1×100 patient-years) and 29 thromboembolic events (rate 0.9×100 patient-years) were recorded, and 46 patients (rate 1.5×100 patient-years) underwent reoperation. The rate of reoperation was higher among younger patients: 32.9% in patients <60 years and 3.9% in patients ≥60 years (relative risk (RR) 3.8, 95% CI 2.1 to 7.2; p=0.0001). When patients were analysed according to age <65 or ≥65 years and <75 or ≥70 years, younger patients still were at higher risk for reoperation (RR 3.1, 95% CI 1.7 to 6.0 and 3.7, 95% CI 1.7 to 8.6, respectively).

Conclusions

Our findings suggest that the threshold of 65 years for implanting a BV should be carefully evaluated, considering the high risk for reoperation and the high risk of AF occurrence with persisting need for long-term anticoagulation. The high risk for reoperation of young patients implanted with BV and the availability of a safer and easier way to conduct VKA treatment, such as the use of point-of-care devices, should be considered when the type of valve must be chosen.

Portable coagulometer for vitamin K-antagonist monitoring: the patients' point of view

PURPOSE

The aim of this study was to know the patients' point of view on the monitoring of vitamin K-antagonist (VKA) therapy by means of a point of care testing (POCT), ie, using a portable coagulometer by self-testing at home. At first, patients had prothrombin time (PT) international normalized ratio (INR) monitoring at a thrombosis center; afterward, they were shifted to self-testing at home. An interview was done to evaluate the patients' point of view on the two monitoring periods.

PATIENTS AND METHODS

A total of 92 oral anticoagulated patients were enrolled. The questionnaire contained nine questions that elicited a maximum of five closer answers that were arranged in increasing levels of satisfaction: very little, little, enough, much and completely. Percentage of time in therapeutic range (TTR) and adverse events were compared during the two periods of conventional monitoring and self-testing.

RESULTS

The period of conventional monitoring was shorter than that of self-testing (p<0.0001), and the median TTR was satisfactory but lower than that of self-testing (p<0.0001). A total of 85% of the patients were satisfied with self-testing at home. In all, 83% and 73% (p=0.06) of patients felt comfortable about side effects while measuring the PT INR at both home and the thrombosis center, respectively. During the self-testing period, quality of life was improved in 87% of the patients. The cost of test strips was medium-high for 89% of the patients, and 75% of them stated that it was worth improving their quality of life. A switch from VKA to a direct oral anticoagulant (DOAC) was proposed to 24% of the patients, but 68% of them declined because they felt more comfortable monitoring their oral anticoagulant therapy by POCT.

CONCLUSION

VKA monitoring using POCT at home may play a role in improving the patients' quality of life and may be considered as an alternative to the use of DOAC at least in certain settings of patients.