scholarly journals Should we Test the Prothrombin Time in Anticoagulated Epistaxis Patients?

2013 ◽  
Vol 4 (1) ◽  
pp. ar.2013.4.0049 ◽  
Author(s):  
Michael B. Soyka ◽  
David Holzmann
Keyword(s):  
Prothrombin Time ◽  
Vitamin K ◽  
Oral Anticoagulation ◽  
Vitamin K Antagonists ◽  
International Normalized Ratio ◽  
Increased Risk

Epistaxis is one of the most frequent emergencies in rhinology. Patients using anticoagulative medication are at increased risk for epistaxis. We evaluated the prothrombin time and the international normalized ratio (INR) in anticoagulated epistaxis patients. Patients suffering from epistaxis were prospectively included in a database and results from prothrombin testing were analyzed in the context of anticoagulation. One hundred sixteen of 591 epistaxis cases were identified to be on oral anticoagulation. The INR was found to be above therapeutic levels in 19 (16%) of these cases. We strongly recommend prothrombin time and INR testing in all epistaxis patients taking any sort of vitamin K antagonists.

Spectrophotometric Assays of Prothrombin in Plasma of Patients Using Oral Anticoagulants

1979 ◽  
Vol 42 (04) ◽  
pp. 1296-1305 ◽  
Author(s):  
R M Bertina ◽  
W van der Marel-van Nieuwkoop ◽  
E A Loeliger
Keyword(s):  
Prothrombin Time ◽  
Vitamin K ◽  
Oral Anticoagulation ◽  
Vitamin K Antagonists ◽  
Oral Anticoagulants ◽  
Factor Xa ◽  
Factor V ◽  
Anticoagulant Treatment ◽  
Factor Ii ◽  
K Deficiency

SummaryTwo spectrophotometric assays for prothrombin have been developed and compared with a one stage coagulant and an immunological assay. One of these assays (called the XAPC assay) uses a combination of factor Xa, phospholipid, Ca2+ and factor V as activator of prothrombin, and measures only normal prothrombin. The second (the ECAR assay) uses Echis carinatus venom as activator. This assay measures both normal prothrombin and PIVKA II (protein induced by vitamin K antagonists/absence). Combination of the results obtained by the XAPC and ECAR assays provides rapid and reliable information on the degree of “subcarboxylation” of prothrombin (oral anticoagulation, vitamin K deficiency).For patients on long term anticoagulant treatment the prothrombin time (Thrombotest) shows better correlation with the ratio prothrombin/prothrombin plus PIVKA II (XAPC/ ECAR) than with the factor II concentration. For patients starting the anticoagulant treatment there is no correlation between the Thrombotest time and the XAPC/ECAR ratio.It seems doubtful that (a) spectrophotometric factor II assay(s) will be as useful as the prothrombin time in the control of oral anticoagulation.

scholarly journals New artificial intelligence prediction model using serial prothrombin time international normalized ratio measurements in atrial fibrillation patients on vitamin K antagonists: GARFIELD-AF

2019 ◽  
Vol 6 (5) ◽  
pp. 301-309 ◽  
Author(s):  
Shinichi Goto ◽  
Shinya Goto ◽  
Karen S Pieper ◽  
Jean-Pierre Bassand ◽  
Alan John Camm ◽  
...  
Keyword(s):  
Neural Network ◽  
Artificial Intelligence ◽  
Atrial Fibrillation ◽  
Prothrombin Time ◽  
Clinical Outcomes ◽  
Vitamin K ◽  
Vitamin K Antagonists ◽  
International Normalized Ratio ◽  
One Dimensional ◽  
Major Bleed

Abstract Aims Most clinical risk stratification models are based on measurement at a single time-point rather than serial measurements. Artificial intelligence (AI) is able to predict one-dimensional outcomes from multi-dimensional datasets. Using data from Global Anticoagulant Registry in the Field (GARFIELD)-AF registry, a new AI model was developed for predicting clinical outcomes in atrial fibrillation (AF) patients up to 1 year based on sequential measures of prothrombin time international normalized ratio (PT-INR) within 30 days of enrolment. Methods and results Patients with newly diagnosed AF who were treated with vitamin K antagonists (VKAs) and had at least three measurements of PT-INR taken over the first 30 days after prescription were analysed. The AI model was constructed with multilayer neural network including long short-term memory and one-dimensional convolution layers. The neural network was trained using PT-INR measurements within days 0–30 after starting treatment and clinical outcomes over days 31–365 in a derivation cohort (cohorts 1–3; n = 3185). Accuracy of the AI model at predicting major bleed, stroke/systemic embolism (SE), and death was assessed in a validation cohort (cohorts 4–5; n = 1523). The model’s c-statistic for predicting major bleed, stroke/SE, and all-cause death was 0.75, 0.70, and 0.61, respectively. Conclusions Using serial PT-INR values collected within 1 month after starting VKA, the new AI model performed better than time in therapeutic range at predicting clinical outcomes occurring up to 12 months thereafter. Serial PT-INR values contain important information that can be analysed by computer to help predict adverse clinical outcomes.

scholarly journals Effectivity of a joint didactic intervention by School for Patients on inappropriate control prothrombin time anticoagulated patients. Protocol for developing a randomized and controlled clinical trial.

2020 ◽  
Author(s):  
Leovigildo Ginel-Mendoza ◽  
Alfonso Hidalgo Hidalgo-Natera ◽  
Rocio Reina-Gonzalez ◽  
Rafael Poyato-Ramos ◽  
Inmaculada Lupianez-Perez ◽  
...  
Keyword(s):  
Social Support ◽  
Clinical Trial ◽  
Prothrombin Time ◽  
Vitamin K ◽  
Oral Anticoagulant ◽  
Vitamin K Antagonists ◽  
International Normalized Ratio ◽  
Control Group ◽  
Therapeutic Level ◽  
Anticoagulated Patients

Abstract Background Oral anticoagulant drugs represent an essential tool in thrombo-embolic events prevention. Most used are vitamin K antagonists, whose plasma level is monitored by measuring prothrombin time using the International Normalized Ratio. If it takes values out of the recommended range, the patient will have a higher risk of suffering from thromboembolic or hemorrhagic complications. Previous research has shown that about 33% of total patients keep values on inappropriate level. The purpose of the study is to improve International Normalized Ratio control figures by a joint didactic intervention based on the Junta de Andalucía School for Patients method that will be implemented by anticoagulated patients themselves. Methods A randomized clinical trial was carried out at primary care centers from one healthcare area in Málaga (Andalusia, Spain). Study population: patients included in an oral anticoagulant therapy program consisting in using vitamin K antagonists. First step detection of patients on oral anticoagulation program with International Normalized Ratio control on therapeutic level during 65% or less over total time. Second step: patients with inappropriate International Normalized Ratio control were included in two groups: Group 1 or Joint Intervention Group: patients were instructed a joint didactic intervention “from peer to peer”, by a previously trained and expert anticoagulated patient. Group 2 or Control Group: Control group performed usual clinical practice: people were schedule by nurses about one time per month, except cases in which controls were inappropriate; in those circumstances patients were schedule before that period expired. In order to built the study group and the control group, 312 individuals were required (156 in each group) to detect differences in INR figures equal or higher than 15% between both groups. Study variables time on therapeutic levels before and after intervention, sociodemographic variables, vital signs, existence of cardiovascular risk factors or accompanying diseases in the clinical records, laboratory test including complete blood count, bleeding time, and prothrombin time or partial thromboplastin time and blood chemistry, other prescribed drugs, and social support. Almost-experimental analytic study with before-after statistical analysis of the intervention were made. Lineal regression models were applied on main variables results (International Normalized Ratio value, time on therapeutic level) inputting sociodemographic variables, accompanying diseases and social support.

High Soluble Thrombomodulin Is Associated with an Increased Risk of Major Bleeding during Treatment with Oral Anticoagulants: A Case–Cohort Study

2020 ◽  
Author(s):  
Myrthe M. A. Toorop ◽  
Nienke van Rein ◽  
Suzanne C. Cannegieter ◽  
Felix J. M. van der Meer ◽  
Pieter H. Reitsma ◽  
...  
Keyword(s):  
Cohort Study ◽  
Vitamin K ◽  
Major Bleeding ◽  
Cox Regression ◽  
Vitamin K Antagonists ◽  
Oral Anticoagulants ◽  
International Normalized Ratio ◽  
Soluble Thrombomodulin ◽  
Major Bleed ◽  
Increased Risk

Abstract Background Major bleeding occurs in 1 to 3% of patients treated with oral anticoagulants per year. Biomarkers may help to identify high-risk patients. A proposed marker for major bleeding while using anticoagulants is soluble thrombomodulin (sTM). Methods Plasma was available from 16,570 patients of the BLEEDS cohort that consisted of patients who started treatment with vitamin K antagonists between 2012 and 2014. A case–cohort study was performed including all patients with a major bleed (n = 326) during follow-up and a random sample of individuals selected at baseline (n = 652). Plasma sTM levels were measured and stratified by percentiles. Patients were also categorized by international normalized ratio (INR). Adjusted hazard ratios (for age, sex, hypertension, and diabetes) with 95% confidence intervals (CIs) were estimated by means of Cox regression. Results Plasma sTM levels were available for 263 patients with a major bleed and 538 control subjects. sTM levels were dose-dependently associated with risk of major bleeding, with a 1.9-fold increased risk (95% CI: 1.1–3.1) for levels above the 85th percentile versus the <25th percentile. A high INR (≥4) in the presence of high (≥70th percentile) sTM levels was associated with a 7.1-fold (95% CI: 4.1–12.3) increased risk of major bleeding, corresponding with a bleeding rate of 14.1 per 100 patient-years. Conclusion High sTM levels at the start of treatment are associated with major bleeding during vitamin K antagonist treatment, particularly in the presence of a high INR.

scholarly journals Vitamin K for reversal of excessive vitamin K antagonist anticoagulation: a systematic review and meta-analysis

2019 ◽  
Vol 3 (5) ◽  
pp. 789-796 ◽  
Author(s):  
Rasha Khatib ◽  
Maja Ludwikowska ◽  
Daniel M. Witt ◽  
Jack Ansell ◽  
Nathan P. Clark ◽  
...  
Keyword(s):  
Vitamin K ◽  
Meta Analysis ◽  
Vitamin K Antagonists ◽  
International Normalized Ratio ◽  
Assessment Development ◽  
Randomized Controlled ◽  
Risk Of Mortality ◽  
Increased Risk ◽  
Meta Analyses ◽  
Risk Ratios

Abstract Patients receiving vitamin K antagonists (VKAs) with an international normalized ratio (INR) between 4.5 and 10 are at increased risk of bleeding. We systematically reviewed the literature to evaluate the effectiveness and safety of administering vitamin K in patients receiving VKA therapy with INR between 4.5 and 10 and without bleeding. Medline, Embase, and Cochrane databases were searched for relevant randomized controlled trials in April 2018. Search strategy included terms vitamin K administration and VKA-related terms. Reference lists of relevant studies were reviewed, and experts in the field were contacted for relevant papers. Two investigators independently screened and collected data. Risk ratios (RRs) were calculated, and certainty of the evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation. Six studies (1074 participants) were included in the review and meta-analyses. Pooled estimates indicate a nonsignificant increased risk of mortality (RR = 1.42; 95% confidence interval [CI], 0.62-2.47), bleeding (RR = 2.24; 95% CI, 0.81-7.27), and thromboembolism (RR = 1.29; 95% CI, 0.35-4.78) for vitamin K administration, with moderate certainty of the evidence resulting from serious imprecision as CIs included potential for benefit and harm. Patients receiving vitamin K had a nonsignificant increase in the likelihood of reaching goal INR (1.95; 95% CI, 0.88-4.33), with very low certainty of the evidence resulting from serious risk of bias, inconsistency, and imprecision. Our findings indicate that patients on VKA therapy who have an INR between 4.5 and 10.0 without bleeding are not likely to benefit from vitamin K administration in addition to temporary VKA cessation.

Subtherapeutic Anticoagulation Control under Treatment with Vitamin K-Antagonists—Data from a Specialized Coagulation Service

2019 ◽  
Vol 119 (08) ◽  
pp. 1347-1357 ◽  
Author(s):  
Jürgen H. Prochaska ◽  
Christoph Hausner ◽  
Markus Nagler ◽  
Sebastian Göbel ◽  
Lisa Eggebrecht ◽  
...  
Keyword(s):  
Risk Factors ◽  
Vitamin K ◽  
Cox Regression ◽  
Statistical Significance ◽  
Vitamin K Antagonists ◽  
International Normalized Ratio ◽  
Living Alone ◽  
Cox Regression Analysis ◽  
Increased Risk ◽  
Anticoagulation Control

AbstractIn contrast to overanticoagulation, evidence on risk factors and outcome of subtherapeutic oral anticoagulation (OAC) with vitamin K-antagonists (VKAs) under optimum care is limited. We investigated the clinical phenotype, anticoagulation control, and clinical outcome of 760 VKA patients who received OAC therapy by a specialized coagulation service in the thrombEVAL study (NCT01809015). During 281,934 treatment days, 278 patients experience ≥ 1 episode of subtherapeutic anticoagulation control and had lower quality of OAC therapy compared to 482 patients without subtherapeutic international normalized ratio: 67.6%, interquartile range (IQR) 54.9%/76.8% versus 81.0%, IQR 68.5%/90.4%; p < 0.001. In Cox regression analysis with adjustment for age, sex, cardiovascular risk factors, comorbidities, and treatment characteristics, female sex (hazard ratio [HR], 1.4, 95% confidence interval [CI], 1.0/1.9; p = 0.03), diabetes (HR, 1.4, 95% CI, 1.0/2.0; p = 0.03), and living alone (HR, 1.5, 95% CI, 1.1/2.1; p = 0.009) were independent risk factors of subtherapeutic anticoagulation control, whereas atrial fibrillation (HR, 0.6, 95% CI, 0.4/0.9; p = 0.02) and self-management of OAC therapy (HR, 0.2, 95% CI, 0.1/0.6; p = 0.001) were protective. In addition, active smoking (HR, 1.7, 95% CI, 0.9/3.0; p = 0.086) and living in a nursing home (HR, 1.6, 95% CI, 0.8/3.2; p = 0.15) indicated an elevated risk at the borderline of statistical significance. For the prediction of recurrent subtherapeutic anticoagulation, living alone was the only independent risk factor (HR, 1.7, 95% CI, 1.1/2.5; p = 0.013). The present study suggests that women, diabetics, and patients living alone experience an increased risk of low-quality VKA therapy and might potentially benefit from treatment with direct-acting anticoagulants.

Decreased Levels Of Procoagulant Phospholipids In Bleeding Patients With Overcoagulation By Vitamin K Antagonists

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4768-4768
Author(s):  
Patrick Van Dreden ◽  
Dominique François ◽  
Emmanuel Mathieu ◽  
Matthieu Grusse ◽  
Marc Vasse
Keyword(s):  
Vitamin K ◽  
Conflicts Of Interest ◽  
Vitamin K Antagonists ◽  
Factor Xa ◽  
International Normalized Ratio ◽  
Bleeding Complications ◽  
Functional Assay ◽  
Minor Bleeding ◽  
Asymptomatic Patients ◽  
Increased Risk

Background The major adverse effect of vitamin K antagonists (VKA) is the increased risk for bleeding complications. In addition to well-identified risk factors such as age, prior gastrointestinal tract bleeding, or hypertension, the intensity of anticoagulation evaluated by the International Normalized Ratio (INR) measurement is a major determinant of VKA-induced bleeding. However, for the same degree of VKA overcoagulation and comorbidities, some patient will bleed, whereas others remain asymptomatic. Therefore, identifying specific biological markers that identify patients at high risk of bleeding would have great clinical impact. Microparticles, derived from different cellular origins (endothelium, red blood cells, leukocytes, platelets or apoptotic tissues), can be detected in plasma and express procoagulant phospholipids (PPL). The presence of PPL has been associated with various diseases complicated by an hypercoagulable state. Therefore, we hypothesize that the procoagulant activity of PPL could protect against haemorrhage in patients with VKA overcoagulation. Patients and methods 53 consecutive patients who were referred to the emergency department of our institution and with an INR > 5 were enrolled in the study: 22 (10 females; 12 males, median age 82 years) were symptomatic (20 cases of minor bleeding, 2 cases of non-fatal major bleeding), whereas 31 (18 females, 13 males, median age 78 years) were asymptomatic. Median INR was 7.36 (range: 5 – 22.6) and 6.3 (range: 5 – 10.7) in symptomatic and asymptomatic patients, respectively (p = 0.17, not significant). PPL were evaluated using a factor Xa-based coagulation assay (STA-Procoag-PPL, Diagnostica Stago) in which shortened clotting times are associated with increased levels of PPL. We also quantified thrombomodulin (TM) by an ELISA assay (Asserachrom Thrombomodulin, Diagnostica Stago) and by a functional assay based on the ability of TM to activate Protein C in the presence of thrombin, since high plasma levels of TM were previously identified as a predictor of bleeding complications. Results Clotting times were significantly lower in asymptomatic patients than in bleeding patients [respective median values 36.5 seconds (range: 27.1 – 72.2) and 47.2 seconds (range : 30.5 – 72.8); p = 0.03. In contrast, there were no significant differences for TM levels, whatever the assay used (functional or immunological). Conclusion Increased PPL could contribute to decrease the haemorrhagic risk of patients treated by VKA. It is not clear if the decrease of PPL is directly responsible of the hemorrhagic syndrom, or if PPL are decreased because of a consumption during the hemorrhagic episode. In order to answer this question, it could be of interest to analyse if a prospective follow-up of this parameter could help to identify patients with an increased hemorrhagic risk when treated by VKA. Disclosures: No relevant conflicts of interest to declare.

scholarly journals The effect of vitamin K on prothrombin time in critically ill patients: an observational registry study

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Sofia Dahlberg ◽  
Ulf Schött ◽  
Thomas Kander
Keyword(s):  
Propensity Score ◽  
Prothrombin Time ◽  
Critically Ill ◽  
Vitamin K ◽  
Critically Ill Patients ◽  
International Normalized Ratio ◽  
University Hospital ◽  
Red Blood Cell Transfusion ◽  
Registry Study ◽  
Exclusion Criteria

Abstract Background Previous studies have indicated that vitamin K deficiency is common in non-bleeding critically ill patients with slightly prolonged prothrombin time-international normalized ratio (PT-INR). It has never been investigated thoroughly whether the administration of vitamin K to these patients could affect their PT-INR. Therefore, the aim of this registry study was to evaluate changes in PT-INR in response to vitamin K in critically ill patients with PT-INR in the range of 1.3–1.9. Methods Patients admitted to a mixed 9-bed general intensive care unit at a University Hospital, between 2013 and 2019 (n = 4541) with a PT-INR between 1.3 and 1.9 at any time during the stay were identified. Patients who received vitamin K with appropriate sampling times for PT-INR and without exclusion criteria were matched with propensity score to patients from the same cohort who did not receive vitamin K (controls). PT-INR was measured at admission, within 12 h before vitamin K administration and 12–36 h following vitamin K administration. Exclusion criteria included pre-existing liver cirrhosis, any plasma or platelet transfusion, or > 1 unit red blood cell transfusion between PT-INR samplings. Results Propensity score matching resulted in two groups of patients with 129 patients in each group. PT-INR decreased in both groups (1.4 [1.3–1.4] in the vitamin K group and 1.4 [1.3–1.6] in the controls, p < 0.001 and p = 0.004, respectively). The decrease in PT-INR was slightly more pronounced in patients who received vitamin K (delta PT-INR − 0.10 [− 0.30 to − 0.10] in the vitamin K group and − 0.10 [− 0.20 to 0.10] in the controls, p = 0.01). Conclusion In critically ill patients with a PT-INR of 1.3–1.9, the administration of vitamin K resulted in a slightly larger decrease of PT-INR 12–36 h after administration compared to controls. Future studies should focus on identifying which patient populations may benefit most from vitamin K administration as well as whether vitamin K could be a better alternative than plasma or prothrombin complex concentrate to improve PT-INR before non-emergent invasive procedures.

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