Computer-aided dosage in oral anticoagulation therapy using phenprocoumon

2010 ◽  
Vol 30 (04) ◽  
pp. 183-189 ◽  
Author(s):  
H. Völler ◽  
F. Gäbler ◽  
A. Salzwedel ◽  
U. Taborski ◽  
L. Cromme
Keyword(s):  
Oral Anticoagulation ◽  
Vitamin K Antagonists ◽  
Anticoagulation Therapy ◽  
Target Range ◽  
Patient Specific ◽  
Oral Anticoagulation Therapy ◽  
Delayed Effects ◽  
Measurement Results ◽  
Computer Aided ◽  
And Control

SummaryOral anticoagulation using vitamin K antagonists has been established for over 50 years. Although it is highly effective in preventing thromboembolic incidents, its therapeutic control still remains problematic. Therefore, a computer-aided approach is recommended for deriving dosages. Up to now, the dosage is often based on the visual inspection of previous INR measurements, average weekly doses, and the INR target range. Statistical variations of measurement results and time-delayed effects of dosages, however, frequently result in the misinterpretation of data and suggest pseudo-trends. Treating physicians are not only responsible for determining the patient-specific maintenance dose, but must also respond to deviating INR values, overdosage or underdosage, initiate the oral anticoagulation therapy, and control the INR level in case of a new target range (bridging). Instructive examples are provided to illustrate the described difficulties.A computer-aided expert system is currently developed to ensure the therapeutic safety under the specified conditions. We present preliminary results from a study designed to validate mathematical models underlying such expert systems.

The Influence of Prior Oral Anticoagulation Therapy on the Anticoagulant Effect of Low Molecular Weight Heparin.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4080-4080
Author(s):  
Soumaya El Rouby ◽  
Urvashi Patel ◽  
Marsha Patsh ◽  
Marc Cohen ◽  
Marcia L. Zucker ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Oral Anticoagulation ◽  
Anticoagulation Therapy ◽  
Warfarin Dose ◽  
Patient Specific ◽  
Low Molecular Weight ◽  
Oral Anticoagulation Therapy ◽  
Blood Samples ◽  
Peak Response

Abstract Low Molecular Weight Heparins (LMWHs) have been suggested by the ACCP as an alternative to UFH for the anticoagulation of patients on chronic oral anticoagulation therapy (OAT) with warfarin. However, the optimal way to manage these patients remains to be established particularly for high-risk patients who require any type of general surgery or urgent invasive PCI procedures. The purpose of this study is to evaluate the LMWH point-of-care (POC) HEMONOXTM assay (Edison, NJ) in patients on chronic OAT. This clot-based test uses rTF reagents and the Hemochron Jr. Signature+ system. The Hemonox clotting time (CT) was analyzed at baseline and at peak response post enoxaparin treatment. Following IRB approval, blood samples from patients on chronic OAT (5 to 20 years, n=13) were evaluated with the Hemonox assay within 12– 18 hours of their last warfarin dose, patients were evaluated weekly for 4 –12 consecutive weeks. In vitro enoxaparin dose response was evaluated by adding 1 U/ml to blood samples obtained from the OAT patients. In supplemental clinical evaluation, 2 PCI cases on OAT were performed at Newark Beth Israel Medical Center, Newark, NJ. Patients were anticoagulated during their PCI procedure with enoxaparin at a final IV dose of 0.5 mg/kg Hemonox CT baseline response was patient specific and the same response profile was obtained for each patient on OAT who underwent consecutive weekly testing. The majority of patients on OAT (9/13; 69%) exhibited elevated Hemonox baseline CT (150–350 secs) when compared to the previously reported range for PCI patients without prior OAT (baseline CT < 100 secs in 100% of cases, Mean = 71.2 ± 9.0, n= 39). Three patients on OAT (23%) showed CT≤150 secs, and only one patient (8%) yielded a baseline < 100 secs. When the blood of the patient with baseline < 100 sec (baseline value = 70 secs) was spiked in vitro with 1 U/ml enoxaparin, the Hemonox CT was 339 secs which was comparable with the peak response (386 and 308 secs; anti-Xa activity = 0.70 ± 0.01 U/ml; concentration of enoxaparin in the circulation = 0.77± 0.13) observed in the PCI patients receiving enoxaparin (0.5 mg/kg IV) and with a prior OAT who showed similar baseline values. Spiked samples from clinic patients with Hemonox baseline > 150 secs were > 700 secs. Our results demonstrate that prior to administration of LMWH, baseline monitoring may be helpful in patients on OAT to alert clinicians to appropriate alterations of enoxaparin dosing and target anticoagulation times due to the influence of warfarin.

scholarly journals The prevalence of long-term oral anticoagulation therapy in a cardiology center in Bucharest, Romania

2018 ◽  
Vol 91 (1) ◽  
pp. 37-41
Author(s):  
Adelina-Mihaela Sorescu ◽  
Tudor Enache ◽  
Suzana Guberna
Keyword(s):  
Oral Anticoagulation ◽  
Economic Status ◽  
Vitamin K Antagonists ◽  
Oral Anticoagulants ◽  
Anticoagulation Therapy ◽  
Cross Sectional Study ◽  
Similar Data ◽  
Cross Sectional ◽  
Oral Anticoagulation Therapy ◽  
Vein Thrombosis

Background and aims. Few studies discuss the prevalence of oral anticoagulation therapy (OAT) in clinical practice, despite their increasing use worldwide. In America, studies established that 20% to 80% of the patients with indication benefit from OAT. In Romania, there is no data regarding the utilization of oral anticoagulants. Thus, this study aims to determine the trends of OAT.Methods. We designed a cross-sectional study of the patients admitted to the Cardiology Department of the “Bagdasar-Arseni” Clinical Emergency Hospital, Bucharest, from the 1st of November 2016 until the 31st of January 2017. We considered OAT indications to be: atrial fibrillation/flutter (AF), pulmonary embolisms (PE), deep vein thrombosis (DVT), intramural or intracavitary thrombi and left ventricle aneurysms. Statistical analysis was performed with EpiInfo.Results. There were 783 patients admitted, 253 of these having an OAT indication (mean age 73.25 years, 53.75% female). Only 162 patients (64.03%) received it, either Vitamin K Antagonists (VKA) (78 patients, 48.14%), or Novel Oral Anticoagulants (NOAC) (84 patients, 51.85%). Reasons for not indicating such therapy included the hemorrhage risk (43.27%), the lack of adherence to the treatment (18.56%), the impossibility of INR monitoring (21.84%), the economic status (10.21%) and others (6.12%). 221 patients had AF (87.35%), 141 (63.8%) receiving OAT, VKA (67 patients, 47.51%), or NOAC (74 patients, 52.48%). 17 patients (6.71%) had a PE and/or DVT. 15 (88.23%) received OAT, AVK (11 patients, 73.33%), or NOAC (4 patients, 26.67%). 15 patients (5.92%) had other OAT indications (excepting AF or PE/DVT), 11 receiving OAT (73.33%), AVK (8 patients, 72.72%), or NOAC (3 patients, 27.27%).Conclusions. Our study determined that 64.03% of those with indication received OAT. Similar data is reported in the USA, suggesting an underuse of anticoagulants. The risk of hemorrhage, lack of adherence, the impossibility of INR monitoring or the economic status were some of the reasons for not recommending OAT.

Self-testing and self-management of oral anticoagulation therapy in children

2011 ◽  
Vol 106 (09) ◽  
pp. 391-397 ◽  
Author(s):  
Torben Larsen ◽  
Vibeke Hjortdal ◽  
Thomas Christensen
Keyword(s):  
Children And Adolescents ◽  
Oral Anticoagulation ◽  
Treatment Options ◽  
Anticoagulation Therapy ◽  
Self Management ◽  
Target Range ◽  
Oral Anticoagulation Therapy ◽  
Clinical Endpoints ◽  
Conventional Management ◽  
Self Testing

SummaryChildren and adolescents on oral anticoagulation therapy (OAT) present special challenges in terms of rapid fluctuations in International Normalised Ratio (INR) values, interruption in daily life due to frequent hospital/doctor visits, and difficulties and pain in the performance of venepuncture. Optimised management of OAT improves the quality of treatment, potentially accomplished by new methods such as patient self-testing (PST) and patient self-management (PSM). A review was performed, identifying 11 trials with children and adolescents. All studies had different methodological problems, predominantly by being non-randomised trials. A total of 284 patients were included with a mean follow-up of 22 months, finding a time within therapeutic INR target range between 63% and 84%. The coagulometers used for estimating the INR values were found to have sufficient precision and accuracy for clinical use, but external quality control is probably advisable. It can be concluded that PST and PSM are at least as good treatment options as conventional management in highly selected children. Larger studies, preferably randomised, controlled trials using clinical endpoints, are obviously needed in order to elucidate whether these new regimens of treatment are superior to conventional management of oral anticoagulation therapy.

scholarly journals Impact of oral anticoagulation therapy on postoperative atrial fibrillation outcomes: a systematic review and meta-analysis

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Mariana Fragão-Marques ◽  
Francisco Teixeira ◽  
Jennifer Mancio ◽  
Nair Seixas ◽  
João Rocha-Neves ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Cardiac Surgery ◽  
Oral Anticoagulation ◽  
Vitamin K Antagonists ◽  
Oral Anticoagulants ◽  
Random Effect ◽  
Anticoagulation Therapy ◽  
Thromboembolic Events ◽  
Oral Anticoagulation Therapy ◽  
All Cause Mortality

Abstract Background Post-operative atrial fibrillation (POAF) is the most common complication after cardiac surgery. Recent studies had shown this phenomenon is no longer considered transitory and is associated with higher risk of thromboembolic events or death. The aim of this study was to systematically review and analyze previous studies comparing oral anticoagulation therapy with no anticoagulation, regarding these long-term outcomes. Methods PubMed/MEDLINE, EMBASE, Web of Science and Cochrane Database were systematically searched to identify the studies comparing the risk of stroke, or thromboembolic events or mortality of POAF patients who received anticoagulation compared with those who were not anticoagulated. Incidence of stroke, thromboembolic events and all-cause mortality were evaluated up to 10 years after surgery. Time-to-event outcomes were collected through hazard ratio (HR) along with their variance and the early endpoints using frequencies or odds ratio (OR). Random effect models were used to compute statistical combined measures and 95% confidence intervals (CI). Heterogeneity was evaluated through Q statistic-related measures of variance (Tau2, I2, Chi-squared test). Results Eight observational cohort studies were selected, including 15,335 patients (3492 on Oral Anticoagulants (OAC) vs 11,429 without OAC) that met the inclusion criteria for qualitative synthesis. Patients had a wide gender distribution (38.6–82.3%), each study with a mean age above 65 years (67.5–85). Vitamin K antagonists were commonly prescribed anticoagulants (74.3–100%). OAC was associated with a protective impact on all-cause mortality at a mean of 5.0 years of follow-up (HR is 0.85 [0.72–1.01]; p = 0.07; I2 = 48%). Thromboembolic events did not differ between the two treatment arms (HR 0.68 [0.40–1.15], p = 0.15). Conclusion Current literature suggests a possibly protective impact of OAC therapy for all-cause mortality in patients with new-onset atrial fibrillation after cardiac surgery. However, it does not appear to impact thromboembolism rate.

scholarly journals Chronic Oral Anticoagulation and Clinical Outcome in Hospitalized COVID-19 Patients

2021 ◽  
Author(s):  
Vincenzo Russo ◽  
Roberta Bottino ◽  
Antonello D’Andrea ◽  
Angelo Silverio ◽  
Marco Di Maio ◽  
...  
Keyword(s):  
Clinical Outcome ◽  
Vitamin K ◽  
Oral Anticoagulation ◽  
Vitamin K Antagonists ◽  
Oral Anticoagulants ◽  
Anticoagulation Therapy ◽  
Study Groups ◽  
Oral Anticoagulation Therapy ◽  
Risk Of Mortality ◽  
Artery Disease

Abstract Purpose The clinical course of COVID-19 may be complicated by acute respiratory distress syndrome (ARDS) and thromboembolic events, which are associated with high risk of mortality. Although previous studies reported a lower rate of death in patients treated with heparin, the potential benefit of chronic oral anticoagulation therapy (OAT) remains unknown. We aimed to investigate the association between OAT with the risk of ARDS and mortality in hospitalized patients with COVID-19. Methods This is a multicenter retrospective Italian study including consecutive patients hospitalized for COVID-19 from March 1 to April 22, 2020, at six Italian hospitals. Patients were divided into two groups according to the chronic assumption of oral anticoagulants. Results Overall, 427 patients were included; 87 patients (19%) were in the OAT group. Of them, 54 patients (13%) were on treatment with non-vitamin k oral anticoagulants (NOACs) and 33 (8%) with vitamin-K antagonists (VKAs). OAT patients were older and had a higher rate of hypertension, diabetes, and coronary artery disease compared to No-OAT group. The rate of ARDS at admission (26% vs 28%, P=0.834), or developed during the hospitalization (9% vs 10%, P=0.915), was similar between study groups; in-hospital mortality (22% vs 26%, P=0.395) was also comparable. After balancing for potential confounders by using the propensity score matching technique, no differences were found in term of clinical outcome between OAT and No-OAT patients Conclusion Oral anticoagulation therapy, either NOACs or VKAs, did not influence the risk of ARDS or death in patients hospitalized with COVID-19.

Ervaringen tijdens de "Belgian Improvement Study on Oral Anticoagulation Therapy" (BISOAT)

2005 ◽  
Vol 61 (11) ◽  
pp. 841-847 ◽  
Author(s):  
CLAES N ◽  
BUNTINX F ◽  
VIJGEN J ◽  
ARNOUT J ◽  
VERMYLEN J ◽  
...  
Keyword(s):  
Oral Anticoagulation ◽  
Anticoagulation Therapy ◽  
Oral Anticoagulation Therapy

Depression and Uptake of Oral Anticoagulation Therapy in Patients With Atrial Fibrillation

Medical Care ◽  
2020 ◽  
Vol 58 (3) ◽  
pp. 216-224 ◽  
Author(s):  
Morten Fenger-Grøn ◽  
Claus H. Vestergaard ◽  
Lars Frost ◽  
Dimitry S. Davydow ◽  
Erik T. Parner ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Oral Anticoagulation ◽  
Anticoagulation Therapy ◽  
Oral Anticoagulation Therapy

Consideration of non-valvular atrial fibrillation with left atrial appendage thrombus formation despite under appropriate oral anticoagulation therapy

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
H Shiraki ◽  
H Tanaka ◽  
K Yamashita ◽  
Y Tanaka ◽  
K Sumimoto ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Logistic Regression ◽  
Regression Analysis ◽  
Oral Anticoagulation ◽  
Left Atrial ◽  
Thrombus Formation ◽  
Anticoagulation Therapy ◽  
Left Ventricular ◽  
Volume Index ◽  
Oral Anticoagulation Therapy

Abstract Background Atrial fibrillation (AF) is the most frequently sustained cardiac arrhythmia, with a prevalence of about 2–3% in the general population. In accordance with CHADS2 or CHA2DS2-VASc score, appropriate oral anticoagulation therapy such as warfarin or direct oral anticoagulants (DOAC) significantly reduced the risk of thromboembolic events. However, left atrial (LA) thrombus can be detected in the LA appendage (LAA) in AF patients despite appropriate oral anticoagulation therapy. Purpose Our purpose was to investigate the associated factors of LAA thrombus formation in non-valvular atrial fibrillation (NVAF) patients despite under appropriate oral anticoagulation therapy. Methods We retrospectively studied consecutive 286 NVAF patients for scheduled catheter ablation or electrical cardioversion for AF in our institution between February 2017 and September 2019. Mean age was 67.1±9.4 years, 79 patients (29.5%) were female, and 140 (52.2%) were paroxysmal AF. All patients underwent transthoracic and transesophageal echocardiography before catheter ablation or electrical cardioversion. All patients received appropriate oral anticoagulation therapy including warfarin or DOAC for at least 3 weeks prior to transesophageal echocardiography based on the current guidelines. LAA thrombus was defined as an echodense intracavitary mass distinct from the underlying endocardium and not caused by pectinate muscles by at least three senior echocardiologists. Results Of 286 NVAF patients with under appropriate oral anticoagulation therapy, LAA thrombus was observed in 9 patients (3.3%). Univariate logistic regression analysis showed that age, paroxysmal AF, CHADS2 score ≥3, left ventricular end-diastolic volume index (LVEDVI), left ventricular ejection fraction (LVEF), left ventricular mass index (LVMI), LA volume index (LAVI), mitral inflow E and mitral e' annular velocities ratio (E/e'), and LAA flow were associated with LAA thrombus formation. It was noteworthy that multivariate logistic regression analysis showed that LAA flow was independent predictor of LAA thrombus (OR: 0.72, 95% CI: 0.59–0.89, p<0.005) as well as LVEF. Furthermore, receiver operating characteristic (ROC) curve analysis identified the optimal cutoff value of LAA flow for predicting LAA thrombus as ≤15cm/s, with a sensitivity of 88%, specificity of 93%, and area under the curve (AUC) of 0.95. Conclusions LAA flow was strongly associated with LAA thrombus formation even in NVAF patients with appropriate oral anticoagulation therapy. According to our findings, further strengthen of oral anticoagulation therapy or percutaneous transcatheter closure of the LAA may be considered in NVAF patients with appropriate oral anticoagulation therapy but low LAA flow, especially <15cm/s. Funding Acknowledgement Type of funding source: None

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