MORE EARLY BLEEDS ASSOCIATED WITH HIGH BASELINE DIRECT ORAL ANTICOAGULANT LEVELS IN ATRIAL FIBRILLATION: THE MAS STUDY.

Treatment with direct oral anticoagulants (DOAC) in atrial fibrillation (AF) patients is effective and safe. However, bleeding complications still occur. Whether the measurement of DOAC levels may further improve treatment efficacy and safety is still an open issue. In the "Measure and See" (MAS) Study (#NCT03803579) venous blood was collected 15-30 days after DOAC initiation in AF patients who were then followed for one year to record the occurrence of major and clinically relevant non-major bleeding. DOAC plasma levels were measured in one laboratory, and results were kept blind to patients and treating doctors. Trough DOAC levels were assessed in 1657 patients [957 (57.7%) and 700 treated with standard and low-dose, respectively]. Fifty bleeding events were recorded during 1606 years of follow-up (3.11% pt/yrs). Fifteen bleeding events (4.97% pt/yrs) occurred in patients with C-trough standardized values in the highest activity class (> 0.50); whereas 35 events (2.69% pt/yrs) occurred in those with values in the two lower classes ( 0.50, p= 0.0401). Increasing DOAC levels and low-dose DOAC use were associated with increased bleeding risk in the first three months of treatment. 19% of patients receiving low doses had standardized activity values in the highest class. More bleeding occurred in patients treated with low (4.3% pt/yrs) than standard (2.2% pt/yrs; p= 0.0160) dose DOAC. Early measurement of DOAC levels in AF patients identified many subjects with high activity levels despite the low doses use and had more bleeding risk during the first 3 months of treatment.

Thrombotic events associated with low baseline direct oral anticoagulant levels in atrial fibrillation: the MAS study.

ABSTRACT: Although effective and safe, treatment with direct oral anticoagulants (DOAC) in atrial fibrillation (AF) is still associated with thrombotic complications. Whether the measurement of DOAC levels may improve treatment efficacy is an open issue. We carried out the observational, prospective, multicenter Measure and See (MAS) study. Blood was collected 15 to 30 days after starting DOAC treatment in patients with AF who were followed-up for 1 year. Plasma samples were centralized for DOAC level measurement. Patients' DOAC levels were converted into drug/dosage standardized values to allow a pooled analysis in a time-dependent, competitive-risk model. The measured values were transformed into standardized values (representing the distance of each value from the overall mean) by subtracting the DOAC-specific mean value from the original values and dividing by the standard deviation. Trough and peak DOAC levels were assessed in 1657 and 1303 patients, respectively. In total, 21 thrombotic complications were recorded during 1606 years of follow-up (incidence of 1.31% of patients per year). Of 21 thrombotic events, 17 occurred in patients whose standardized activity levels were below the mean of each DOAC (0); the incidence was the highest (4.82% of patients per year) in patients whose standardized values were in the lowest class (-1.00 or less). Early measurement of DOAC levels in patients with AF allowed us to identify most of the patients who, having low baseline DOAC levels, subsequently developed thrombotic complications. Further studies are warranted to assess whether thrombotic complications may be reduced by measuring baseline DOAC levels and modifying treatment when indicated. This trial was registered at www.ClinicalTrials.gov as #NCT03803579.

Leukocyte cell population data as potential markers of COVID-19 disease characterization.

Background: The usefulness of leukocyte cell population data (CPD) is currently being investigated. In COVID-19 pandemic several reports showed the clinical importance of hematological parameters. Our study aimed to assess CPDs in Sars CoV-2 patients as new disease markers. Methods: From February to April 2020 (1st wave) 540 and from September to December 2020 (2nd wave) 2821 patients respectively were enrolled. SARS CoV-2 infection diagnosis was carried out by Multiplex rRT-PCR from nasopharyngeal swabs. CPDs were detected by XN 2000 hematology analyzer (Sysmex Corporation). A comparison between two disease waves was performed. Additionally, C-reactive protein (CRP) and lactate dehydrogenase (LDH) were assayed. Results: CPDs were classified into: cell complextity, DNA/RNA content and abnormal sized cells. We detected parameters increased from the reference population for all cell types for both 1st and 2nd wave (p<0.05). However, in the 2nd vs 1st wave 5 CPDs vs 9 CPDs were found. In addition we observed higher CPD values of the 1st compared to 2nd wave: (NE-SFL) (p<0.001), (LY-Y) (p<0.0001), (LY-Z) (p<0.0001), (MO-X) (p<0.0001), (MO-Y) (p<0.0001). These findings were confirmed by the higher concentrations of CRP and LDH in the 1st vs 2nd wave: 17.3 mg/L (8.5-59.3) vs 6.3 mg/L (2.3-17.6) (p<0.001) and 241.5 IU/L (201-345) vs 195 IU/L (174-228) (p< 0.001) (median, interquartile range) respectively. Conclusions: CPDs showed increased cell activation in 1st wave patients confirmed by clinical and biochemical data, associated with worse clinical conditions. Results highlighted the CPDs as disease characterization markers or useful for a risk model.

Time in therapeutic range is lower in women than in men and is not explained by differences in age or comorbidity.

BACKGROUND: Time in therapeutic range (TTR) measures the stability of the international normalized ratio in patients on vitamin K antagonists (VKA). Low values are associated with poor outcomes. Women were shown to have lower TTR than men, but the causes are poorly defined. It was suggested that women on VKA are older and more morbid than men, and this could affect the stability of anticoagulation. We aimed to identify variables that affect TTR differently in women and men. MATERIALS AND METHODS: This is a retrospective study in patients referred to a University hospital anticoagulant clinic. Age, sex, comorbidities, number of daily medications, indication and type of anticoagulant, weekly dosage and distribution, were derived from electronic records. Differences by sex and regression analysis to identify significant modulators of TTR were computed. RESULTS: 1182 women and 1281 men on VKA were studied. Women were older than men (81.5 yrs. ± 11.2 vs 78.4 yrs. ± 12.2), and had lower TTR (65% ± 20.3 vs 69% ± 19.8). Comorbidity was similar between sexes and negatively affected TTR in both. Mechanical valves as an indication to anticoagulation and acenocoumarol as an anticoagulant as opposed to warfarin had a strong negative influence on TTR, while age increased TTR. Being a man rather than a woman afforded more than three TTR points. Number of medications and average anticoagulant dose were equal between sexes. DISCUSSION: Women have a lower TTR than men, on average below the safety threshold. They were indeed older, but age positively influenced TTR. Since women and men were equally comorbid, neither age nor disease explains differences in TTR. None of the other variables included in the study could explain the gender gap in TTR. Since women are at increased risk of cardioembolic stroke in atrial fibrillation, an effort at defining other causes for the observed differences, closer monitoring and switching to direct anticoagulants whenever possible is warranted.

Safety and effectiveness of biosimilar enoxaparin (Inhixa) for the prevention of thromboembolism in medical and surgical inpatients.

In 2016, biosimilar enoxaparin (Inhixa®, Techdow) was introduced in European markets with the same indications as branded enoxaparin (Clexane®, Sanofi). Its use is constantly increasing in clinical practice, however, little information from post-marketing clinical trials is available on its safety and effectiveness. We conducted an observational, retrospective study to assess the safety and effectiveness of Inhixa in preventing venous thromboembolism (VTE) in medically ill patients and in patients undergoing major abdominal surgery. We then compared our results with the incidence of symptomatic VTE and bleeding events during treatment with Clexane by pooling the results of clinical studies carried out in the same settings. We enrolled 381 patients, 189 admitted to a Medical Department and 192 to a Surgical Department from two single institutions. The incidence of major bleeding events was 1.8% globally (95% IC 0.7-3.8), 1.6% in medical patients (95% IC 0.3-4.6) and 2.1% in surgical patients (95% IC 0.6-5.3). VTE rate was 0.5% in the whole population (95% IC 0.1-1.9) and 0.5% (95% IC 0.01-2.9) in each group, respectively. The pooled estimate of the incidence of major bleeding with Clexane was 0.5% (IC 95%: 0.2-1.1) in medical patients and 2.6% (IC 95% 1.3-5.1) in surgical patients. The incidence of thrombotic events was 0.6% (IC 95%: 0.2-1.8) and 0.7% (CI95% 0.3-1.6), respectively. The incidence of bleeding and thrombosis in medical and surgical patients receiving Inhixa was low suggesting biosimilar enoxaparin is a valid alternative to branded enoxaparin.

Failure of the Anticoagulant Therapy and Psychological Distress: Still Far From a Bridge.

Background: The procoagulant stress response reflects part of a beneficial adaptation of the organism to environmental threats, but a protracted procoagulant state generates a thrombotic risk. Atrial fibrillation (AF) is the most common arrhythmia in the general population. Patients with AF have a higher risk of thromboembolic events and stroke, therefore they are treated with long-term oral anticoagulant (OAC) therapy. The aim of this study is to evaluate if there is any association between psychological distress and clinically unexplained variations of the International Normalized Ratio (INR), that is the index used to monitor both thromboembolic and bleeding risk in the case of patients under OAC therapy. Methods: Fifty-eight patients (men = 27; women = 31; mean age = 74.98) were recruited. The sample was divided according to the recognition (or not) of the reason why the INR was subtherapeutic (<2) and classified as "Known Reasons" (KR = 32.8%) and "Unknown Reasons" (UR = 67.2%). Psychological assessment included the following dimensions: symptoms of anxiety and depression, perceived stress, emotional regulation strategies, and alexithymia. Results: Considering Mann-Whitney test results, no significant difference was found in the scores of anxiety, depression, stress, and emotional regulation strategies. With regard to alexithymia, UR patients are characterized by a moderate tendency to an outward-oriented thinking (r = 0.25). Conclusion: A clear role for the detected psychological factors in determining abnormal INR range in patients under OAC therapy could not be found. Further studies are needed to support our findings, if possible exploring factors other than psychological distress and the related emotion regulation strategies.

Sex, gender and venous thromboembolism: do we care enough?

: The role of sex and gender in determining clinical presentation, diagnostic approach and outcomes of venous thromboembolism is not fully and systematically addressed, except for hormone-related events in women. A lack of knowledge is also apparent regarding drug prescription patterns, physician bias, enrolment in clinical studies and analysis of sex-related confounders in preclinical and clinical studies. As was shown for cardiovascular disease, ignoring sex and gender in medicine can have important impact on outcomes, including mortality. In this review, we seek to address some aspects of venous thromboembolism such as epidemiology and clinical presentation, recurrence, risk factors, animal studies, safety and efficacy of antithrombotic drugs, highlighting what is known and what is not regarding the role of sex and gender, and hoping to focus some interest and to promote the inclusion of these variables in all future studies on venous thromboembolism.

Atrial fibrillation and psychological factors: a systematic review.

BACKGROUND: Psychological factors have been suggested to have an influence in Atrial Fibrillation (AF) onset, progression, severity and outcomes, but their role is unclear and mainly focused on anxiety and depression. METHODS: A systematic electronic search had been conducted to identify studies exploring different psychological factors in AF. The search retrieved 832 articles that were reviewed according to inclusion criteria: observational study with a control/comparison group; use of standardized and validated instruments for psychological assessment. Results were summarized qualitatively and quantitatively by effect size measure (Cohen's d and its 95% confidence interval). Cochrane Collaboration guidelines and the PRISMA Statement were adopted. RESULTS: Eight studies were included in the systematic review. Depression was the most studied construct/ but only one study showed a clear link with AF. The remaining studies showed small and non-significant (95% CI [-0.25-1.00]) differences between AF and controls, no differences in frequency of depression history (95% CI [-0.14-0.22]) or in case frequency (95% CI [-0.50-0.04]). Miscellaneous results were found as far as anxiety: AF patients showed higher levels when compared to healthy subjects (95% CI [2.05-2.95]), but findings were inconsistent when compared to other heart diseases. Considering personality and life-events preceding AF, we respectively found a large (95% CI [1.87-2.49]) and a moderate to large effect (95% CI [0.48-0.98]). DISCUSSION: The small number of studies does not allow to draw clear-cut conclusions on the involvement of psychological factors in AF. Promising lines of research are related to personality and adverse life-events, and to the increase of longitudinal design studies. Some methodological problems could be overcome by including clinical psychologists in the implementation of research protocols.

Naturally occurring N(6)-substituted adenosines (cytokinin ribosides) are in vitro inhibitors of platelet aggregation: an in silico evaluation of their interaction with the P2Y(12) receptor.

A few naturally occurring N(6)-substituted adenosine derivatives (cytokinin ribosides) were investigated as inhibitors of platelet aggregation induced in vitro by collagen and their activity range was demonstrated (IC50: 6.77-141 µM). A docking study suggests that anti-aggregation activity of these compounds could involve an interaction with the P2Y12 receptor binding site.

To be or not to be: the patient's view of thrombophilia testing.

INTRODUCTION: The literature on the psychological effects of thrombophilia testing is unclear. Little is known about the complex world of significance subjects construct around the test. OBJECTIVE: The study explored the peculiar network of implicit meanings that may be linked to the experience of being tested. MATERIALS AND METHODS: The research was designed according to Interpretative Phenomenological Analysis (IPA). 19 patients were interviewed. Integral verbatim reports of the interviews were analyzed through an inductive process aimed at gaining a holistic understanding of the narratives. RESULTS: Two main issues were identified, each with sub-issues: (1) the clinical problem: (1.1) unhealthy blood and (1.2) the family issue; (2) the test: (2.1) knowing for the sake of knowing; (2.2) knowing for the sake of doing; (2.3) not knowing. CONCLUSIONS: The thrombophilia test is part of a larger network of meanings, where information about the test and its results seem to be lost. PRACTICE IMPLICATION: The study suggests the importance of paying greater attention to the process of doctor-patient communication at the time of the test. The theme of being informed is important for patients, yet often they are not able to understand or retain the information they receive, increasing the risk of misunderstandings.

Why does ticagrelor induce dyspnea?

In studies that compared the reversible P2Y12 inhibitor ticagrelor with the irreversible inhibitor clopidogrel, dyspnea was observed more frequently among ticagrelor-treated patients than among clopidogrel-treated patients. Because dyspnea was not associated with acidosis, pulmonary or cardiac dysfunction, alterations in the mechanisms and pathways of the sensation of dyspnea may be involved in its pathogenesis. It has been hypothesised that the sensation of dyspnea in ticagrelor-treated patients is triggered by adenosine, because ticagrelor inhibits its clearance, thereby increasing its concentration in the circulation. However, dipyridamole, a much stronger inhibitor of adenosine clearance than ticagrelor, usually does not cause dyspnea. We hypothesise that inhibition of P2Y12 on sensory neurons increases the sensation of dyspnea, particularly when reversible inhibitors are used. We base our hypothesis on the following considerations: 1) cangrelor and elinogrel, which, like ticagrelor, are reversible P2Y12 inhibitors, also increase the incidence of dyspnea; 2) it is biologically plausible that inhibition of P2Y12 on sensory neurons increases the sensation of dyspnea; 3) inhibition of P2Y12 on platelets (which do not have a nucleus) by clopidogrel is permanent, despite the once daily administration and the short plasma half-life of the inhibitor; 4) in contrast, inhibition of P2Y12 on neurons by clopidogrel may be temporary and transient, because neurons have a nucleus and can therefore rapidly replace the inhibited receptors with newly synthetised ones; 5) inhibition of P2Y12 on neurons by reversible inhibitors is permanent, because the plasma drug concentration is maintained high by repeated dosing, in order to ensure permanent inhibition of platelet P2Y12.

Levels of soluble endothelial protein C receptor are associated with CD4+ changes in Maraviroc-treated HIV-infected patients.

BACKGROUND: Inflammation is a key feature of HIV infection and is correlated with long-term negative cardiovascular outcomes. Therapy-induced increases in CD4(+) cell counts can control inflammation, as shown by decreases of coagulation and inflammation markers during efficacious therapy. Maraviroc, a CCR5-antagonist, has resulted in larger increases in CD4(+) counts both in naïve and experienced subjects compared to traditional antiretroviral therapy. OBJECTIVES AND METHODS: To examine if a member of the protein C anticoagulant and anti-inflammatory pathway, and marker of coagulation and inflammation, the soluble endothelial protein C receptor, is modified by infection and therapy-related variables in patients treated with Maraviroc. Endothelial protein C receptor, together with other established markers of inflammation and coagulation (CRP, IL-6, D-dimer and soluble thrombomodulin) was studied in 43 patients on traditional antiretroviral therapy and in 45 on Maraviroc during 48 weeks of follow-up. RESULTS: Soluble endothelial protein C receptor was the only marker that could discriminate at least partially between patients with a good response to Maraviroc and patients who did not respond with an adequate increase in CD4(+) cell counts (more than 500 cells/µL by week 48). CONCLUSIONS: Elevated levels of soluble endothelial protein C receptor, a sensitive marker of endothelial damage, indicated a low level of inflammation and coagulation activation in Maraviroc treated patients not picked up by other widely used markers. Persistent elevated levels of this marker at 48 weeks from beginning of treatment with Maraviroc were related to a poor increase in CD4(+) cells.

Screening for thrombophilia and antithrombotic prophylaxis in pregnancy: Guidelines of the Italian Society for Haemostasis and Thrombosis (SISET).

The term thrombophilia describes an increased tendency to develop thrombosis and many laboratory markers with different strengths of association with thrombosis have been identified. The main causes of maternal mortality and morbidity in developed countries is venous thromboembolism (VTE) and obstetric complications. During pregnancy and puerperium the risk for VTE increases due to hemostatic imbalance towards a prothrombotic state, and it is further increased in women carriers of thrombophilia; recent studies have also demonstrated an association between thrombophilia and obstetric complications. These complications are, therefore, considered potentially preventable with the prophylactic administration of anticoagulant drugs, although their efficacy is not proven by data from randomized controlled trials. After a systematic comprehensive literature review and using a rigorous methodology, the expert panel formulated recommendations regarding the usefulness of screening for thrombophilia in pregnancy to identify high-risk women and for the management of antithrombotic prophyalxis. When evidence is lacking, consensus-based recommendations are provided.

Determination of vitamin K1 in plasma by solid phase extraction and HPLC with fluorescence detection.

We describe a procedure for quantification of vitamin K(1) in human plasma by HPLC. Samples, enriched with a vitamin K derivative as internal standard, were deproteinized, purified on polymeric RP-SPE cartridges and injected into HPLC equipped with a post-column on-line zinc metal reactor and a fluorometric detector. Median level in blood donors (n=87) was 1.967 nmol/L (0.93-4.01, 5th-95th percentiles), with a significant correlation between plasma levels and age (r=0.276, p=0.00958) and a lower (not significant) value in women than in men. This method, easy-to-handle and with a high throughput, can be used to identify covert states of vitamin K intake deficiency in patients thus at risk of alterations in blood clotting or bone mineralization.

ProCMD: a database and 3D web resource for protein C mutants.

BACKGROUND: Activated Protein C (ProC) is an anticoagulant plasma serine protease which also plays an important role in controlling inflammation and cell proliferation. Several mutations of the gene are associated with phenotypic functional deficiency of protein C, and with the risk of developing venous thrombosis. Structure prediction and computational analysis of the mutants have proven to be a valuable aid in understanding the molecular aspects of clinical thrombophilia. RESULTS: We have built a specialized relational database and a search tool for natural mutants of protein C. It contains 195 entries that include 182 missense and 13 stop mutations. A menu driven search engine allows the user to retrieve stored information for each variant, that include genetic as well as structural data and a multiple alignment highlighting the substituted position. Molecular models of variants can be visualized with interactive tools; PDB coordinates of the models are also available for further analysis. Furthermore, an automatic modelling interface allows the user to generate multiple alignments and 3D models of new variants. CONCLUSION: ProCMD is an up-to-date interactive mutant database that integrates phenotypical descriptions with functional and structural data obtained by computational approaches. It will be useful in the research and clinical fields to help elucidate the chain of events leading from a molecular defect to the related disease. It is available for academics at the URL http://www.itb.cnr.it/procmd/.

Abnormalities of homocysteine and B vitamins in the nephrotic syndrome.

INTRODUCTION: The nephrotic syndrome is associated with heightened risk for arterial and venous thrombosis. Multiple derangements of hemostasis and acquired risk factors such as hyperlipidemia and hypertension contribute to this risk. The prevalence in the nephrotic syndrome of high circulating levels of homocysteine and of low levels of the B vitamins that are involved in its metabolism, which may play a role in thrombosis, is not well defined. MATERIALS AND METHODS: In 84 patients with nephrotic syndrome and 84 sex- and age-matched controls, hemostasis variables and the circulating levels of total homocysteine (tHcy), vitamin B(6), B(12) and folates were measured. RESULTS: tHcy levels were higher, vitamin B(6) and vitamin B(12) levels were lower in nephrotic patients than in controls. The association of low vitamin B(6) levels with the nephrotic syndrome was independent of any other alteration associated with the disease. Eighty-two percent of patients with the nephrotic syndrome had vitamin B(6) levels falling in the lowest quartile of the normal distribution. Antithrombin deficiency, factor V Leiden, antiphospholipid antibodies, hypertension, dyslipidemia, were more frequent in patients with the nephrotic syndrome than in controls. CONCLUSIONS: Patients with the nephrotic syndrome have multiple risk factors for thrombosis. We report that they frequently have low circulating levels of vitamin B(6), which associate with a heightened risk for venous and arterial thrombosis.

Identification and computationally-based structural interpretation of naturally occurring variants of human protein C.

Protein C (PC) is a key regulator of blood clotting and inflammation. Its inherited deficiency is associated with venous thromboembolism, and recombinant activated PC is currently used to increase survival in severe sepsis. The molecular basis of inherited PC deficiency is heterogeneous. Due to its multiple physiologic interactions and functions, and its modular structure, natural variants aid in the understanding of the relationship between critical residues and discrete functions. This knowledge has important therapeutic implications in the planning of a recombinant activated PC with a specific therapeutic target and devoid of major collateral effects. A way of predicting important functional consequences of residue variation is the use of molecular modeling and structural interpretation of amino acidic substitutions. A study of 21 out of 32 identified PC gene (PROC) variants is presented. For three of them, localized in the active site, electrostatic potential variation was calculated. For more than half of the studied variants, an explanation for the functional impairment could be derived from computational analysis, allowing a focused choice of which variants it is worthwhile pursuing.