Monitoring Of Anticoagulant Therapy Research Articles

Peptide‐Based Organic‐Inorganic Hybrid Self‐Assemblies for Ultrasensitive and Visual Detection of Heparin

AbstractAccurate point‐of‐care testing (POC) of low molecular weight heparin (LMWH) can efficiently promote its rational use in the prevention and treatment of thromboembolic diseases but still remain a key challenge. Herein, a peptide‐derived supramolecular self‐assembly system is reported for ultrasensitive and visual detection of LMWH. Two different peptides are designed and modified by gold nanocluster (AuNC) and tetraphenylethene (TPE), respectively, to co‐assemble into nanoparticles, enabling the loading and co‐recognition of LMWH. Owing to two‐wavelength emission from the co‐assemblies at 624 and 460 nm that is highly sensitive to LMWH, such assemblies realize ratio‐type detection of LMWH. The sensitivity of the AuNC‐peptide to LMWH significantly increases when co‐assembling with TPE‐peptide, while that of TPE‐peptide maintains in a high level, enabling a balanced and ultrahigh sensitivity of both two fluorophores. Such self‐assemblies reach an extreme limit of detection of 0.0004 IU mL−1 and realize dramatic fluorescence color change when loading trace concentration of LMWH, which can be simply distinguished by naked‐eye. Thus, by preparing Pep2@AuNC/TPE‐Pep1 test strips the POC testing of LMWH in real thrombus patient samples has achieved. It provides a promising tool for on‐site and real‐time monitoring of anticoagulation therapy to guide LMWH titration into the therapeutic window.

Thromboelastography in the Perioperative Period: A Literature Review.

Assessing coagulation status is essential for prompt intervention to reduce morbidity and mortality related to bleeding and thrombotic complications during the perioperative period. Traditional coagulation tests such as platelet count,activated partial thromboplastin time (aPTT), prothrombin time (PT), international normalized ratio (INR), and activated clotting time (ACT) provide only static evaluation. These tests are not designed for assessment of dynamically changing coagulation conditions during the perioperative time. However, viscoelastic coagulation testing such as thromboelastography (TEG) produces a rapid numerical and graphical representation that helps to detect and direct targeted hemostatic therapy. Searching the literature through PubMed, Medline, Ovid, CINAHL, and ClinicalTrials.gov we retrieved 210 studies, which represent the use of TEG in the perioperative period. The included studies were categorized under various settings such as trauma, obstetrics, orthopedics, intensive care unit (ICU), cardiovascular, transplant, and miscellaneous scenarios. TEG showed promising results in trauma surgeries in predicting mortality, hypercoagulability, and bleeding even when it was compared to conventional methods. TEG was also useful in monitoring anticoagulant therapy in orthopedic and obstetric surgeries; however, its role in predicting thrombotic events, hypercoagulability, or complications was questionable. In ICU patients, it showed promising results, especially in the prediction or improvement of sepsis, coagulopathy, thrombotic events, ICU duration, hospital stay, and ventilator duration. TEG parameters effectively predicted hypercoagulation in transplant surgeries. Regarding cardiovascular surgeries, they were effective in the prediction of the need for blood products, coagulopathy, thrombotic events, and monitoring anticoagulation therapy. More randomized clinical trials comparing TEG parameters with standardized tools are needed to produce robust results to standardize its use in different perioperative settings.

Warfarin-Induced Limb Contusion Section and Haematoma

Warfarin is a narrow therapeutic index drug with high potential to cause adverse effects. It is generally a preferred drug for the management of venous thrombosis. This case is an unusual presentation of left arm contusion and limb haematoma secondary to long-term warfarin use. A 32-year-old male patient was admitted with the complaints of left lower limb oedema and left upper arm oedema. He was on warfarin for dural sinus thrombosis for two years. The integrative analysis of patient clinical presentation, medication history, International Normalized Ratio (INR) level, Ultrasonography (USG) scan and Naranjo assessment showed the probable case of warfarin-induced left arm contusion and limb haematoma. The patient was successively managed with the administration of vitamin K, injection heparin, packed red blood cell and other supportive therapy after the withdrawal of the culprit drug. Thus, patients prescribed with warfarin should be looked at for this typical adverse event. Monitoring of anticoagulant therapy is vital for the positive clinical outcome and minimisation of adverse events. Clinical pharmacists have a key role to play in the patient safety and their inputs can fertilise the concept of pharmacist led anticoagulation clinic in India.

Effects of a single subcutaneous dose of enoxaparin on veterinary viscoelastic coagulation monitor variables in healthy cats: Double blind, placebo controlled cross-over trial.

Cats placed on anticoagulant medication require frequent monitoring. The veterinary viscoelastic coagulation monitor (VCM-Vet) could provide a convenient and cost-effective monitoring, enabling therapeutic decision making. Enoxaparin will lead to changes in VCM-Vet variables and these will correlate with antiXa activity. Twenty-one healthy cats. Cats were randomized to receive either enoxaparin (1mg/kg) subcutaneously or 0.9% NaCl (equal volume) and crossed over with a 7-day washout period. The investigators were blinded to group allocation until data analysis. Jugular blood samples were drawn at time 0, and 2, 4, and 8hours after injection for VCM-Vet analysis within 2min of collection. Citrated plasma was frozen at -80°C for antiXa activity analysis. A Generalized Linear Model was completed to assess changes between baseline measurements and all time points. Significant differences between the enoxaparin-treated cats and controls at for T0h and T2h were found and presented as mean ± SD for clotting time (enoxaparin, 593.4 ± 78.0s; control, 448.5 ± 50.3s, P < .001), clot formation time (enoxaparin, 183.1 ± 41.7s; control, 155.4 ± 28.0s, P=.001), and alpha angle (enoxaparin, 52.4 ± 6.1°; control, 56.9 ± 3.7s, P=.003). AntiXa activity was significantly different between T0 and all other timepoints for the enoxaparin group (P < .001). There was no correlation between changes in clotting time and antiXa activity. The VCM-Vet detects a difference at 2hours after single-dose enoxaparin administration and it can be useful for anticoagulant therapy monitoring in cats.

Nticoagulant therapy monitoring in COVID-19 patients in the intensive care unit: thromboelastometry and echocardiography

Aim. To determine the effectiveness of thromboelastometry (TEM) and echocardiography for anticoagulant therapy monitoring in patients with COVID-19.Material and methods. We analyzed treatment regimen of 92 patients with COVID-19. The patients were divided into two groups. In the control group (n=30), anticoagulant therapy with unfractionated heparin (UFH) was carried out under laboratory control of coagulation parameters. In the experimental group (n=62), anticoagulation was maintained by intravenous UFH under control of coagulation, echocardiography (Philips, Epiq 5) and TEM (ROTEM® delta). Echocardiography determined the pulmonary artery acceleration time (AT), mid-systolic notching (SN). The TEM method was used to study external (EXTEM) and internal (INTEM) pathways, differential tests (FIBTEM, HEPTEM) of coagulation. Statistical analysis was performed by calculating non-parametric statistics parameters, comparisons of differences in groups (Mann-Whitney test), area under the curve (AUC), and regression equations.Results. A high correlation level between echocardiographic and TEM parameters was determined. Their levels associated with a positive prognosis were calculated (AT&gt;113,5 ms., AUC 0,979; p&lt;0,0001; no SN, AUC 0,931; p&lt;0,0001; FIBTEM ML (60 min) &gt;1,12%, AUC 0,971, p&lt;0,0001; INTEM ML (60 min) &gt;2,01%, AUC 0,941, p&lt;0,0001, EXTEM ML (60 min) &gt;1,4%, AUC 0,934, p&lt;0,0001; MCFfib not &gt;26 mm, AUC 0,954; p&lt;0,0001; MCFin not &gt;56,6 mm, AUC 0,938; p&lt;0,0001; MCFex not &gt;47,9 mm, AUC 0,838, p&lt;0,0001). In 33,9% of patients in the experimental group, heparin resistance was detected. In this connection, combined therapy with UFH and direct oral anticoagulants (DOACs) was used, followed by the switch to DOACs. In the control group, artificial ventilation was used in 50% of patients, mortality — 36,6%, myocardial infarction — 13,3%, deep vein thrombosis — 6,6%, pulmonary embolism — 6,6%, while in the experimental group, mechanical ventilation — 12,9%, myocardial infarction — 4,8%, mortality — 8,1%.Conclusion. The dynamic assessment of echocardiography and TEM parameters made it possible to monitor pulmonary thrombosis processes, significantly reduce complications, the use of artificial ventilation and mortality in COVID-19 patients.

Laboratory monitoring of anticoagulant therapy

Laboratory monitoring of anticoagulant therapy

Frequency of bleeding complications in Algerian patients treated with the vitamin K antagonist acenocoumarol and associated factors

Background: The major complication of vitamin K antagonist (VKA) therapy is bleeding. This study aimed to estimate the rate of hemorrhagic accidents and identify the hemorrhagic factors in Algerian patients treated by the VKA, acenocoumarol.Methods: We performed a cross-sectional study in patients undergoing VKA therapy, followed in the cardiology department of the University Hospital of Sidi Bel Abbes.Results: One hundred patients were included. We recorded 22 cases of bleeding. Overdose and concomitant use of drugs that interfere with the acenocoumarol effect are significant risk factors of bleeding.Conclusions: Knowledge of predictive factors for VKA-related excessive anticoagulation seems to be of the utmost importance for improving patient management. There is a need for a national registry to assess the efficacy and safety of drug use in the short and long term. This pilot study is a cornerstone in the development of oral anticoagulation therapy monitoring in our region.

Updates in Anticoagulation Therapy Monitoring.

In the past six decades, heparin and warfarin were the primary anticoagulants prescribed for treatment and prophylaxis of venous thromboembolism worldwide. This has been accompanied by extensive clinical knowledge regarding dosing, monitoring, and reversal of these anticoagulants, and the resources required to do so have largely been readily available at small and large centers alike. However, with the advent of newer oral and parenteral anticoagulants such as low molecular weight heparins, factor Xa inhibitors, and direct thrombin inhibitors in recent years, new corresponding practice guidelines have also emerged. A notable shift in the need for monitoring and reversal agents has evolved as well. While this has perhaps streamlined the process for physicians and is often desirable for patients, it has also left a knowledge and resource gap in clinical scenarios for which urgent reversal and monitoring is necessary. An overview of the currently available anticoagulants with a focus on the guidelines and available tests for anticoagulant monitoring will be discussed in this article.

COVID-19: imbalance of multiple systems during infection and importance of therapeutic choice and dosing of cardiac and anti-coagulant therapies.

The renin–angiotensin–aldosterone system and its metabolites play an important role in homeostasis of body, especially the cardiovascular system. In this study, we discuss the imbalance of multiple systems during the infection and the importance of therapeutic choice, dosing, and laboratory monitoring of cardiac and anti-coagulant therapies in COVID-19 patients. The crosstalk between angiotensin, kinin-kallikrein system, as well as inflammatory and coagulation systems plays an essential role in COVID-19. Cardiac complications and coagulopathies imply the crosstalks between the mentioned systems. We believe that the blockage of bradykinin can be a good option in the management of COVID-19 and CVD in patients and that supportive treatment of respiratory and cardiologic complications is needed in COVID-19 patients. Ninety-one percent of COVID-19 patients who were admitted to hospital with a prolonged aPTT were positive for lupus anticoagulant, which increases the risk of thrombosis and prolonged aPTT. Therefore, the question that is posed at this juncture is whether it is safe to use the prophylactic dose of heparin particularly in those with elevated D‐dimer levels. It should be noted that timing is of high importance in anti-coagulant therapy; therefore, we should consider the level of D-dimer, fibrinogen, drug-drug interactions, and risk factors during thromboprophylaxis administration. Fibrinogen is an independent predictor of resistance to heparin and should be considered before thromboprophylaxis. Alteplase and Futhan might be a good choice to assess the condition of heparin resistance. Finally, the treatment option, dosing, and laboratory monitoring of anticoagulant therapy are critical decisions in COVID-19 patients.

Thrombotic diseases and conditions – diagnosis and monitoring of anticoagulant therapy

Laboratory methods are a very important part of the examination of patients with thrombotic diseases, often putting the final touches on the diagnosis, and in some cases even defining this diagnosis. The present review of thrombotic diseases and conditions, as well as the laboratory methods for their diagnosis, enables the differentiation of these conditions in the laboratory phase of the examination and the selection of the correct specific therapy, especially antithrombotic therapy.This review reflects the main nosological forms, causes of thrombotic diseases and conditions, as well as methods of their diagnosis using reagents and test systems of the leading domestic manufacturer of reagents for diagnostics of the hemostatic system SPD “Renam” ICPOD “Hemophilia Society”. The mechanisms of conditions and diseases such as deep vein thrombosis (DVT) and pulmonary artery thromboembolism (PATE), hypercoagulability syndrome (HCS), disseminated intravascular coagulation (DIC), hereditary and acquired thrombophilia (deficiency of antithrombin III, proteins C and S, factor Va resistance to activated protein C, etc.) and complications of anticoagulant therapy (heparin-induced thrombocytopenia (HITC), antiphospholipid syndrome (APS), complications of anticoagulant therapy (heparin-induced thrombocytopenia (HIT), coumarin-induced necrosis, etc.) are reviewed. Laboratory criteria for thrombotic conditions are presented. The most commonly used anticoagulant drugs and their control methods are reviewed, including vitamin K antagonists (oral anticoagulants, OAC), unfractionated heparin (UFH), low molecular weight heparins (LMWH), fondaparinux, direct or new oral anticoagulants (DOACs or NOACs). Laboratory criteria for thrombotic conditions are presented. Methods for determining blood D-dimer are described in detail, as well as methods for measuring anti-Xa and anti-IIa heparin activity.This joint work of the leading employees of the Research and Production Department «Renam» of ICPOD «Hemophilia Society» and FSBI NMRC of Hematology of the Ministry of Health of the Russian Federation reflects the need for scientific and practical cooperation of practitioners, laboratory doctors and manufacturers of reagents and test systems to develop the most sensitive, specific, accurate and convenient methods of disease diagnostics and control of therapy.

91-Year-Old Man With Upper Extremity Ecchymoses

91-Year-Old Man With Upper Extremity Ecchymoses

Integrated management of atrial fibrillation in primary care: results of the ALL-IN cluster randomized trial

AimsTo evaluate whether integrated care for atrial fibrillation (AF) can be safely orchestrated in primary care.Methods and resultsThe ALL-IN trial was a cluster randomized, open-label, pragmatic non-inferiority trial performed in primary care practices in the Netherlands. We randomized 26 practices: 15 to the integrated care intervention and 11 to usual care. The integrated care intervention consisted of (i) quarterly AF check-ups by trained nurses in primary care, also focusing on possibly interfering comorbidities, (ii) monitoring of anticoagulation therapy in primary care, and finally (iii) easy-access availability of consultations from cardiologists and anticoagulation clinics. The primary endpoint was all-cause mortality during 2 years of follow-up. In the intervention arm, 527 out of 941 eligible AF patients aged ≥65 years provided informed consent to undergo the intervention. These 527 patients were compared with 713 AF patients in the control arm receiving usual care. Median age was 77 (interquartile range 72–83) years. The all-cause mortality rate was 3.5 per 100 patient-years in the intervention arm vs. 6.7 per 100 patient-years in the control arm [adjusted hazard ratio (HR) 0.55; 95% confidence interval (CI) 0.37–0.82]. For non-cardiovascular mortality, the adjusted HR was 0.47 (95% CI 0.27–0.82). For other adverse events, no statistically significant differences were observed.ConclusionIn this cluster randomized trial, integrated care for elderly AF patients in primary care showed a 45% reduction in all-cause mortality when compared with usual care.

Interferences between Clot in the Erythrocyte Sediment and Hemostasis Exploration.

The selection and rejection of non-conforming coagulation specimens is essential in safeguarding quality management in hemostasis laboratories that provide routine testing for bleeding and thrombotic disorders. In order to increase quality, it is important to reduce pre-analytical errors that generally account for 60 - 70% of total laboratory failure. The accidental presence of clots in vitro, in the pre-analytical phase of the coagulation, is a reason for coagulation specimen rejection, given that the reliability of test results can be adversely compromised. This study aimed to ascertain the effect of clots identified in the post-analytical phase within the blood sample sediments upon standard laboratory tests such as PT (prothrombin time) and APTT (activated partial thromboplastin time). From a total of 24,670 coagulation specimens gathered and prospectively collected and analyzed at the Haematology Laboratory of the ˮSf. Spiridonˮ Emergency County Hospital Iasi, Romania, during four months, 671 were identified with clot. Of the coagulated samples, 153 (22.80%) were considered for this study, including those specimens pinpointed with sediment clot through a post-analytical new reverification procedure. The comparative study of the PT and APTT results obtained based on the samples identified with sediment clots in relation to the actual results recorded after the repetition of the sampling, pointed out 43.93% false results for PT1 test, with a significant difference between the variances of the values at the two evaluated moments (t = 2.961, p = 0.0037). The pattern was congruent in the case of the APTT test as well, exhibiting 69.04% false results, for which the variances of values at the two evaluated moments displayed significant differences (t = 2.208, p = 0.0306). In both of the cases significantly lower mean values were noted in the second determination of PT (PT1: 33.1 ± 39.6 vs. PT2: 25.8 ± 30.5) and APTT (APTT1: 42.8 ± 42.7 vs. APTT2: 38.1 ± 26.1. Results are important as they highlight the actual interference between the clot in the erythrocyte sediment and the evaluation of the patient's hemostasis. Our results confirm that the presence of clots in the erythrocyte sediment, with no identification prior to centrifugation, significantly affect the PT and APTT analysis, their accurate results being critical for the proper diagnosis and monitoring of anticoagulant therapy.

Coagulation mixing studies: Utility, algorithmic strategies and limitations for lupus anticoagulant testing or follow up of abnormal coagulation tests.

Coagulation testing underpins the investigation of hemostasis and/or monitoring of anticoagulation therapy for prevention and/or treatment of thrombosis related pathology. Assessment of coagulation results requires comparison against a normal reference range or interval (NRR/NRI). Results flagged as "abnormal" (ie, above the NRR/NRI for patients not on anticoagulant therapy), typically require further evaluation. eg, follow up or reflexive testing is used to identify the reason for prolongation, especially when supported by clinical context (eg, bleeding). Mixing tests may have utility to help identify the pathway of follow-up testing (ie, towards investigation of factor deficiencies, or else inhibitors), and are also useful for investigation of lupus anticoagulants (LA). In general, mixing tests that "correct" tend to suggest the presence of factor deficiencies, where as those that do not correct suggest the presence of "inhibitors". Various approaches can be used to identify correction/non-correction, and all have strengths and limitations. Furthermore, eventual identification of causal factor deficiencies or even "inhibitors" may (eg, factor VIII or IX deficiencies or inhibitors) or may not (eg, factor XII deficiency) be clinically important. Ultimately, mixing studies performed in view of appropriate clinical scenarios (eg, bleeding patient) and for LA investigations in symptomatic patients will have best utility.

Development and implementation of an expert rule set for automated reflex testing and validation of routine coagulation tests in a large pathology network.

Haemostasis laboratories play a critical role in diagnosis and treatment of individuals with bleeding or thrombotic disorders. Routine coagulation assays such as prothrombin time (PT)/ international normalized ratio (INR), and activated partial thromboplastin time (APTT), are used in monitoring of anticoagulant therapy, as provided for treatment/prevention of thromboembolic disease, and also inform on potential haemostasis dysfunction. Increasing pressure is applied on clinical laboratories to improve response (test turnaround) times, reduce error rates and standardize policies. To this end, we describe our experience with the development and implementation of an automated process for reflex testing and validation of routine coagulation test results in a large pathology network compromising 27 laboratories. Custom-built expert rules were created to perform reflex testing and fully automate routine test validation. These rules were developed/implemented over a 15-month period, including 6months for development/ testing and 9months for training/implementation of >100 personnel at 27 sites. These rules have enabled adherence of standardized pre-analytical (sample integrity) checks, automated reflex decisions, automated verification and overall alignment of network practices. In addition, clinically significant results are immediately referred to haematologists. We report an improvement in test turnaround times, also reflecting savings in operator time. The process was generally well received and generally beneficial to most laboratories in the network.

Croatian Society of Medical Biochemistry and Laboratory Medicine: National recommendations for blood collection, processing, performance and reporting of results for coagulation screening assays prothrombin time, activated partial thromboplastin time, thrombin time, fibrinogen and D-dimer.

A modern diagnostic laboratory offers wide spectrum of coagulation assays utilized in the diagnosis and management of patients with haemostatic disorders, preoperative screening and anticoagulation therapy monitoring. The recent survey conducted among Croatian medical biochemistry and transfusion laboratories showed the existence of different practice policies in particular phases of laboratory process during coagulation testing and highlighted areas that need improvement. Lack of assay standardization together with non-harmonized test results between different measurement methods, can potentially lead to incorrect decisions in patient’s treatment. Consequently, patient safety could be compromised. Therefore, recommended procedures related to preanalytical, analytical and postanalytical phases of prothrombin time, activated partial thromboplastin time, thrombin time, fibrinogen and D-dimer testing are provided in this review, aiming to help laboratories to generate accurate and reliable test results.

Impact of a Direct Oral Anticoagulant Population Management Tool on Anticoagulation Therapy Monitoring in Clinical Practice.

Background: The optimal monitoring and follow-up strategy for long-term direct oral anticoagulant (DOAC) therapy has not been established. Historically, at our medical center, DOAC patients were referred to a clinical pharmacy specialist managed anticoagulation clinic (AC) for monitoring via regularly scheduled encounters (face-to-face or telephone). Objective: To determine if implementation of a DOAC Population Management Tool (PMT) designed to identify patients who most likely require clinical review and possibly intervention, would improve the efficacy (interventions per patient) and efficiency (time invested to generate an intervention) of monitoring over AC practices. Methods: The DOAC PMT group included patients flagged as potentially having a dosing issue or history of valve replacement. The AC group included patients who were scheduled for routine DOAC follow-up. The quantity and character of interventions made were prospectively recorded and compared. Results: A total of 399 patients were included. Data were collected for 131 patients identified by the DOAC PMT, resulting in a review of 170 flags with a total of 94 interventions or 0.55 interventions per flag reviewed. For the AC group, 268 patients were evaluated, leading to 53 interventions or 0.20 interventions per patient encounter (P < 0.001 for comparison). The time to generate an intervention was 16 minutes in the DOAC PMT versus 64 minutes for the AC group. Conclusion and Relevance: A population-based approach to DOAC monitoring represents a more effective and efficient strategy to reduce missed opportunities for interventions between follow-up appointments while also increasing clinic access, particularly for patients who require immediate attention.

Blood Clot Identification Procedures in Clinical Laboratory Sampling.

Monitoring of anticoagulation therapy is based on screening tests: prothrombin time (PT) and activated partial thromboplastin time (APTT). The accidental presence of a clot in the coagulation samples determines a false prolongation of PT by fibrinogen (FI) consumption and the false or delayed prolongation of APTT, depending on FI consumption or activation. The purpose of this study is to document from the present data re-garding procedures used to exclude the accidental presence of clot in the sample. For a more efficient approach, we conducted a study based on research from the main databases that included original and peer-reviewed studies. We have reported studies in which pre-analytical procedures have been recommended and studies that have also presented post-analytical protocols. A correlation between the efficiency of the procedures in terms of additional laboratory costs has been performed, as well. Focusing on patient safety, it remains a continuous challenge for each laboratory to be able to establish its own pre-analytical and post-analytical procedure for highlighting accidental clot presence, thus ensuring provision of results with maximum confidence to the clinicians.

A Single-Institution Retrospective Study of Causes of Prolonged Prothrombin Time (PT) and Activated Partial Thromboplastin Time (aPTT) in the Outpatient Setting

Background:Prothrombin time (PT) and activated partial thromboplastin time (aPTT) are screening tests of hemostasis commonly ordered for anticoagulant therapy monitoring, evaluation of bleeding, screening for acquired or inherited deficiencies of coagulation factors, and preoperative screening. Evaluation of a prolonged PT/aPTT is best accomplished in an algorithmic fashion consisting of mixing studies and factors assays or inhibitor testing as indicated. However, there is little data available on frequency of conditions that may result in abnormalities of PT/aPTT. The Special Coagulation Laboratory (SCL) at our institution offers an algorithmic approach termed Prolonged PT/aPTT Profile (PT/aPTT profile).Aim:To review our institutional experience with PT/aPTT profile testing (indications and outcomes), and to provide clinical correlation of abnormal PT/aPTT tests on patients seen at our institution in an effort to explain common causes of altered hemostatic testing in outpatient clinical practice.Methods:In this retrospective study, following IRB approval, we reviewed the medical records of patients who underwent outpatient PT/aPTT profile testing in the SCL at Mayo Clinic in Rochester, Minnesota between 2010 and 2017. Data abstracted included patient demographics and clinical presentation, indications for testing, use of anticoagulants, medical diagnoses which could potentially influence coagulation, and results of hemostatic testing (Table 1). Statistical analyses were completed using SAS 9.4 (SAS Institute Inc., Cary, North Carolina). Continuous variables are presented as median (range) while discrete variables are summarized as frequency (percentage). Comparisons of clinical characteristics between groups are made using the rank-sum test for continuous variables. Statistical significance is defined as a 2-tailed P value of less than 0.05.Results:A total of 107 patients met our study criteria, 58 (54 %) male, median age 55 years (range 1-89). Indications for testing included prior prolongation of PT (48%), PTT (29%), PT and aPTT (8%) on outside coagulation testing performed in a non-SCL setting, clinical bleeding episodes (10%) and preoperative screening (5%). Patients with established medical diagnoses known to influence coagulation testing including solid tumors, hematologic malignancies, liver disease, renal disease, autoimmune and rheumatologic conditions and pregnancy were documented along with other baseline patient characteristics (Table 1).SCL PT/aPTT profile testing revealed normal results in 29 of 107 (27%) patients on repeat testing while 78 patients warranted further evaluation of which 27 (35%) had an isolated prolonged PT, 28 (36%) had a prolonged APTT and 23 (29%) had prolongations of both PT and aPTT.After further workup and clinical correlation, causes of abnormal outpatient PT/aPTT profile testing were found to be related to an underlying congenital condition in 16 (21%) patients - most commonly factor VII deficiency (9%) and factor VIII deficiency (4%) - acquired conditions in 53 (68%) patients - most commonly anticoagulant therapy effects (31%) and liver disease (21%) - and of unclear etiology in 7 (9%) cases (Table 2).Specifically, the most common cause of an isolated prolonged PT in our study was found to be vitamin K deficiency (37%) whereas elevations in aPTT and both PT/aPTT were most frequently attributed to the effects of anticoagulant therapy (29% and 52% respectively). Other causes of prolongation on PT/aPTT profile testing following clinical correlation were also identified (Table 2).Discussion:While PT and aPTT are commonly ordered tests, there is little evidence regarding epidemiology of testing indications, distribution of test results, and the clinical correlation of test results. Our study demonstrates that abnormalities in hemostatic testing can be attributed to a wide range of causes including artefactual prolongation influenced by pretest variables or marked abnormalities in secondary hemostasis due to inherited and acquired conditions. Strengths of this study include the SCL algorithmic approach to testing to further elucidate coagulation cascade abnormalities to properly characterize conditions that pose severe hemostatic risk while limitations of this study reflect the experience of a single institution and possible referral bias. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Construction and practice of community database for monitoring anticoagulation therapy after cardiac valve replacement

Objective To construct anticoagulation monitoring database of Northeast patients after heart valve replacement, to provide a long-term and continuous regional long-distance follow-up platform for patients with valvular heart disease in convalescent period and explore the best way to share information between superior hospitals and primary community hospitals. Methods A non-randomized, prospective controlled clinical study was conducted among 485 patients who received warfarin anticoagulation therapy and anticoagulation monitoring after cardiac valve replacement from January 2016 to September 2017 in the Affiliated Hospital of North Medical College and Nanchong Central Hospital. All the patients were divided into outpatient follow-up group (n=242) and remote follow-up group (n=243) . The outpatient follow-up group received routine clinic and telephone follow-up. The remote follow-up group realized the information sharing through the database and accepted the anticoagulation guidance provided by the primary medical institutions. Thromboembolic and hemorrhagic events associated with anticoagulation therapy and international standardized ratio (INR) were analyzed during follow-up. The quality of anticoagulation therapy was evaluated by treatment range time (TTR) . Results There was no significant difference in the INR results during the follow-up time between the two groups (P>0.05) . The TTR value of the outpatient and remote follow-up group was 42.3% and 54.4% respectively, and the difference was statistically significant (P 0.05) . Conclusions Community database of valve disease anticoagulation in northern Sichuan can effectively improve the quality of anticoagulant therapy in these patients, realize the information sharing from superior hospital patients with primary medical institutions, and ensure the convalescence after heart valve replacement of anticoagulant therapy in patients with accuracy and persistence. Key words: Heart valve replacement; Anticoagulation therapy; Registered database