INR Values (inr + value)

Distribution by Scientific Domains


Selected Abstracts


Twelve-month outcomes and predictors of very stable INR control in prevalent warfarin users

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 4 2010
D. M. WITT
Summary., Background:, For patients on warfarin therapy an international normalized ratio (INR) recall interval not exceeding 4 weeks has traditionally been recommended. For patients whose INR values are nearly always therapeutic, less frequent INR monitoring may be feasible. Objective:, To identify patients with stable INRs (INR values exclusively within the INR range) and comparator patients (at least one INR outside the INR range), compare occurrences of thromboembolism, bleeding and death between groups, and identify independent predictors of stable INR control. Methods:, The study was a retrospective, longitudinal cohort study using data extracted from electronic databases. Patient characteristics and risk factors were entered into multivariate logistic regression models to identify variables that independently predict stable INR status. Results:, There were 533 stable and 2555 comparator patients. Bleeding and thromboembolic complications were significantly lower in stable vs. comparator patients (2.1% vs. 4.1% and 0.2% vs. 1.3%, respectively; P < 0.05). Independent predictors of stable INR control were age >70 years, male gender and the absence of heart failure. Stable patients were significantly less likely to have target INR ,3.0 or chronic diseases. Conclusion:, A group of patients with exclusively therapeutic INR values over 12 months is identifiable. In general, these patients are older, have a target INR <3.0, and do not have heart failure and/or other chronic diseases. Our findings suggest that many patients whose INR values remain within the therapeutic range over time could be safely treated with INR recall intervals >4 weeks. [source]


Warfarin for atrial fibrillation in community-based practise

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 10 2008
A. J. ROSE
Summary.,Background:,Previous studies of anticoagulation for atrial fibrillation (AF) have predominantly occurred in academic settings or randomized trials, limiting their generalizability.Objective:,To describe the management of patients with AF anticoagulated with warfarin in community-based practise.Methods:,We enrolled 3396 patients from 101 community-based practises in 38 states. Data included demographics, comorbidities, and International Normalized Ratio (INR) values. Outcomes included time in therapeutic INR range (TTR), stroke, and major hemorrhage.Results:,The mean TTR was 66.5%, but varied widely among patients: 37% had TTR above 75%, while 34% had TTR below 60%. The yearly rates of major hemorrhage and stroke were 1.90 per 100 person-years and 1.00 per 100 person-years. Four percent of patients (n = 127) were intentionally targeted to a lower INR, and spent 42.7% of time with an INR below 2.0, compared to 18.8% for patients with a 2.0,3.0 range (P < 0.001). Mean TTR for new warfarin users (57.5%) remained below that of prevalent users through the first six months. Patients with interruptions of warfarin therapy had lower TTR than all others (61.6% vs. 67.2%, P < 0.001), which corrected after deleting low peri-procedural INR values (67.0% vs. 67.4%, P = 0.73).Conclusions:,Anticoagulation control varies widely among patients taking warfarin for AF. TTR is affected by new warfarin use, procedural interruptions, and INR target range. In this community-based cohort of predominantly prevalent warfarin users, rates of hemorrhage and stroke were low. The risk versus benefit of a lower INR target range to offset bleeding risk remains uncertain. [source]


Laboratory and clinical outcomes of pharmacogenetic vs. clinical protocols for warfarin initiation in orthopedic patients

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 10 2008
P. A. LENZINI
Summary.,Background:,Warfarin is commonly prescribed for prophylaxis and treatment of thromboembolism after orthopedic surgery. During warfarin initiation, out-of-range International Normalized Ratio (INR) values and adverse events are common. Methods:,In orthopedic patients beginning warfarin therapy, we developed and prospectively validated pharmacogenetic and clinical dose refinement algorithms to revise the estimated therapeutic dose after 4 days of therapy. Results:,The pharmacogenetic algorithm used the cytochrome P450 (CYP) 2C9 genotype, smoking status, peri-operative blood loss, liver disease, INR values and dose history to predict the therapeutic dose. The R2 was 82% in a derivation cohort (n = 86) and 70% when used prospectively (n = 146). The R2 of the clinical algorithm that used INR values and dose history to predict the therapeutic dose was 57% in a derivation cohort (n = 178) and 48% in a prospective validation cohort (n = 146). In 1 month of prospective follow-up, the percent time spent in the therapeutic range was 7% higher (95% CI: 2.7,11.7) in the pharmacogenetic cohort. The risk of a laboratory or clinical adverse event was also significantly reduced in the pharmacogenetic cohort (Hazard Ratio 0.54; 95% CI: 0.30,0.97). Conclusions:,Warfarin dose adjustments that incorporate genotype and clinical variables available after four warfarin doses are accurate. In this non-randomized, prospective study, pharmacogenetic dose refinements were associated with more time spent in the therapeutic range and fewer laboratory or clinical adverse events. To facilitate gene-guided warfarin dosing we created a non-profit website, http://www.WarfarinDosing.org. [source]


Activation of the coagulation system occurs within rather than outside cutaneous haemangiomas

ACTA PAEDIATRICA, Issue 10 2001
J Antovic
Haemangiomas are the commonest tumours of infancy. They can become even more serious if followed by consumption coagulopathy and even life-threatening in cases of Kasabach,Merritt syndrome, with thrombocytopenia and haemorrhage. Data exist concerning systemic coagulation abnormalities in children with haemangiomas but to our knowledge there are no data on local consumption coagulopathy in haemangioma per se. We examined blood coagulation and fibrinolysis parameters in blood withdrawn from haemangioma blood vessels and blood withdrawn from the systemic vein in 14 children with cutaneous haemangiomas (3M, 11F; age range 3 mo to 10 y). Compared with controls, significant decreases in fibrinogen levels, FVII activity, antithrombin and plasmin inhibitor levels and increases in international normalized ratio (INR) and D-dimer levels were observed in the blood samples withdrawn directly from haemangioma blood vessels. Fibrinogen and antithrombin levels in samples withdrawn from systemic veins were reduced in relation to control values whilst INR values increased, but within normal ranges. D-dimer levels were increased in peripheral blood. The fibrinogen level was significantly lower and the INR and D-dimer levels were significantly higher in blood samples from haemangiomas compared to systemic blood. Clinical signs of systemic disseminated intravascular coagulation were not observed. Conclusions: Our results suggest a strong local activation and local consumption coagulopathy in haemangioma, along with less conspicuous but observable systemic changes in coagulation and fibrinolysis parameters, although without signs of consumptive coagulopathy. These systemic changes could be a reflection of intra-lesion coagulation activation although there is no evidence to suggest truly systemic disseminated intravascular coagulation. [source]