International Normalized Ratio Levels Research Articles

Are glycoprotein inhibitors safe during percutaneous coronary intervention in patients on chronic warfarin treatment?

The aim of this study was to evaluate the safety of glycoprotein IIb/IIIa inhibitors (GPIs) during percutaneous coronary intervention (PCI) in patients on chronic warfarin therapy due to atrial fibrillation (AF). We analysed all consecutive AF patients (N = 377, mean age 70 years, male 71%) on warfarin therapy referred for PCI in seven centres. Major bleeding, access site complications and major adverse cardiovascular events were recorded during hospitalisation. A total of 111 patients (29%) received periprocedural GPIs with a wide inter-hospital variation in their use (range 3-68%). The use of GPIs increased with the severity of the disease presentation and 49% of patients with ST-elevation myocardial infarction received GPIs. Mean periprocedural international normalised ratio (INR) of patients who received GPIs was 1.89 (range 1.1-3.3). Major bleeding was more common in the patients treated with GPIs (9.0% vs. 1.5%, p = 0.001) than in those without GPIs, but there was no difference in major adverse cardiovascular events between the groups. In multivariable analysis, use of GPIs (odds ratio [OR] 5.1, 95% confidence interval [CI] 1.3-20.6, p = 0.02) and old age (OR 1.2, 95% CI 1.0-1.3, p= 0.02) remained as the only independent predictors of major bleeding. Also after adjusting for propensity score, GPIs remained as a significant predictor of major bleeding (OR 3.8, 95% CI 1.03-14.1, p = 0.045). In the GPI group, major bleeding was not predicted by INR level or warfarin pause. GPIs increase the risk of major bleeding events irrespective of periprocedural INR levels and should be used with caution in this fragile patient group.

Differential inhibition of thrombin generation by vitamin K antagonists alone and associated with low-molecular-weight heparin

Vitamin K antagonists (VKA) treatment starts with co-administration of low-molecular-weight heparin (LMWH). The anticoagulation induced by the two drugs is still not well determined. In the present study we used thrombin generation assay to evaluate the hypo-coagulation induced by treatment with VKA and by the combination of VKA with LMWH. Tissue factor triggered thrombin generation in platelet-poor plasma was assessed in samples from 15 healthy volunteers, 97 samples from patients treated with VKA and 41 samples from patients receiving enoxaparin and VKA. Patients were classified according to international normalised ratio (INR) level (<2, 2-3 and >3). In plasma samples from patients treated with VKA having INR 2-3 the inhibition of thrombin generation reached 50% compared to controls. In samples with INR>3 this inhibition was 80%. In samples from patients receiving both LMWH and VKA, thrombin generation was significantly decreased compared to the controls and VKA group. In samples with an INR 2-3 obtained from patients treated with LMWH and VKA, the inhibition of thrombin generation was similar to that observed in samples with an INR>3 obtained from VKA treated patients. Thrombin generation assay is sensitive to detect the global the anticoagulant effect produced by the association of LMWH and VKA. For equal INR dual anticoagulant treatment induces significantly more profound inhibition of thrombin generation compared to treatment with VKA alone. The clinical relevance of this observation merits to be studied in prospective studies in patients with defined indications of anticoagulant therapy.

Aspirin and clopidogrel with or without phenprocoumon after drug eluting coronary stent placement in patients on chronic oral anticoagulation

Optimal antithrombotic/anticoagulation therapy in patients on chronic oral anticoagulation (OAC) undergoing drug-eluting stent (DES) implantation is unknown. We investigated the efficacy and safety of two regimens of antithrombotic/anticoagulation therapy in patients who present for DES implantation whilst on OAC. We included a series of 515 patients on OAC who underwent DES implantation between 2002 and 2007. Based on predefined clinical and echocardiographic criteria, 306 patients continued OAC (triple therapy) and 209 patients discontinued OAC (dual therapy) for the time they received antiplatelet therapy with clopidogrel and aspirin [stent-related antithrombotic treatment (SRAT)]. The primary end point was a composite of death, myocardial infarction, stent thrombosis or stroke. During SRAT the primary endpoint was observed in 13 patients in the group with triple therapy versus 15 patients in the group with dual therapy [Kaplan-Meier estimates 4.2% and 7.2%, odds ratio (OR) = 0.61, 95% confidence interval (CI) 0.29-1.28; P = 0.19]. At 2 years of follow-up, the primary endpoint was observed in 35 patients in the group with triple therapy versus 36 patients in the group with dual therapy (Kaplan-Meier estimates 14.1% and 18.0%, OR = 0.76, 95% CI: 0.48-1.21; P = 0.25). Two-year incidence of major bleeding was 1.4% (n = 4, triple therapy) versus 3.1% (n = 6, dual therapy) (P = 0.34). In patients on chronic OAC undergoing DES implantation, clinical and echocardiographic criteria help to define postprocedural antithrombotic/anticoagulation therapy. Based on these criteria, both a double antiplatelet therapy (clopidogrel plus aspirin) and a triple therapy (OAC plus clopidogrel plus aspirin) are associated with favourable safety and efficacy.

Warfarin

See related article, pages 235–240. In 1989, the Copenhagen AFASAK study1 reported results from the first randomized, placebo-controlled trial evaluating adjusted-dose warfarin and aspirin in the prevention of stroke for nonvalvular atrial fibrillation (NVAF). Like the 5 randomized, placebo-controlled trials that came after it,2 the Copenhagen AFASAK study demonstrated a reduction in embolic events in patients taking warfarin. Today, the weight of evidence from 18 trials comparing warfarin with either placebo or antiplatelet drugs overwhelmingly favors the use of warfarin for stroke prevention in NVAF.2,3 In 20 years since AFASAK and 10 years since the first meta-analysis of trials testing the effect of warfarin on stroke risk,4 anticoagulation has remained underused and opportunities for preventing fatal and disabling stroke have been frequently missed.5–12 In this issue of Stroke , Gladstone and colleagues5 report a prospective practice audit of 920 patients presenting with ischemic stroke and a history of atrial fibrillation to 12 hospitals in Ontario, Canada. All patients had a high risk of stroke. Approximately 60% of the 597 patients with a first-ever stroke were not receiving warfarin at the time of admission. Of those receiving warfarin, approximately three fourths had a subtherapeutic international normalized ratio (INR) recorded on admission. A further 323 patients with a history of stroke or transient ischemic attack arguably had the most to gain from warfarin. Approximately 40% of this group was not on warfarin at the time of admission, whereas 70% of those using warfarin had subtherapeutic INR levels. These findings are disturbing because all patients included in the audit were judged to be “ideal candidates” for warfarin, living independently without known contraindications to anticoagulation. Gladstone et al5 highlight the severity of stroke in patients with NVAF. Eighty percent of the patients with a first-ever stroke …

Epidemiology and outcomes in patients with atrial fibrillation in the United States

Nonrheumatic atrial fibrillation (AF) is a common cause of embolic stroke. Warfarin therapy can reduce stroke risk by two-thirds in patients with AF, but therapy may not always be used or always be used optimally. This study sought to document the patterns of anticoagulant use and the determinants and incidence of stroke, intracranial hemorrhage, and arterial thromboembolism in US patients with AF. Using health insurance claims and laboratory results, we examined events per unit of person-time and used Poisson regression to quantify the association of AF outcomes with the international normalized ratio (INR) and other covariates. In 116,969 patients age > or =40 years with an insurance claim for AF or atrial flutter between 1999 and 2005, warfarin was prescribed to 45%, and 48% had no claim for any anticoagulant or antiplatelet agent. Subtherapeutic INR levels (<2.0) raised the incidence of stroke (relative risk [RR]: 2.39, 95% confidence interval [CI]: 1.68 to 3.41) and arterial thromboembolism (RR: 5.68, 95% CI: 1.88 to 17.10) compared with therapeutic INR levels, whereas supratherapeutic INR levels (>3.0) doubled the incidence of intracranial hemorrhage (RR: 2.11, 95% CI: 1.16 to 3.84). Further covariate adjustment had little effect on these estimates. Warfarin remains underused within the outpatient setting. Nontherapeutic INR levels are associated with increased risk of stroke, bleeding, and thromboembolism compared with therapeutic INR levels.

Hydroxyethyl starch versus Ringer solution in cardiopulmonary bypass prime solutions (a randomized controlled trial)

BackgroundIn our study we compared the Ringer solution, which is the standard prime solution of our department, with the HES (Hydroxyethyl starch) 130-0.4 solution, which can be a potential alternative prime solution with an indispensable material for the cardio-pulmonary bypass applications.Methods140 patients undergoing to CABG (Coronary Artery Bypass Graft surgery) were electively enrolled to the study. 1500 ml Ringer solution + 200 ml mannitol + 60 ml sodium bicarbonate + 150 U/kg heparin was used as a prime solution to start cardiopulmonary by-pass in 70 patients which was defined as group 1. On the other hand, 1500 ml HES 130 - 0.4 + 200 ml mannitol + 60 ml sodium bicarbonate + 150 U/kg heparin was used as a prime solution in 70 patients in group 2.ResultsINR (International Normalized Ratio), urea levels and blood platelet counts were significantly different between the groups. INR level was higher in group 1, while blood urea and creatinine levels and platelet count were higher in group 2 at the end of the 12th and 24nd hours postoperatively (p = 0.001).In this study, it was shown that the usage of HES 130-0.4 as a prime solution did not have negative effect on postoperative INR level, platelet count, the need for transfusion and the amount of drainage, despite the negative opinions that similar solutions caused coagulation disorders. Another interesting result of the study was that blood platelet count at 24th hour was statistically significantly higher in group 2 (p = 0.001).ConclusionHES 130-0.4 solution is an alternative colloidal solution which can be used as the prime solution or as a mixture with the crystalloids in cardio-pulmonary bypass applications.

Quality of anticoagulation and use of warfarin-interacting medications in long-term care: A chart review

BackgroundMaintenance of therapeutic International Normalized Ratio (INR) in the community is generally poor. The supervised environment in long-term care facilities may represent a more ideal setting for warfarin therapy since laboratory monitoring, compliance, dose adjustment, and interacting medications can all be monitored and controlled. The objectives of this study were to determine how effectively warfarin was administered to a cohort of residents in long-term care facilities, to identify the proportion of residents prescribed warfarin-interacting drugs and to ascertain factors associated with poor INR control.MethodsA chart review of 105 residents receiving warfarin therapy in five long-term care facilities in Hamilton, Ontario was performed. Data were collected on INR levels, warfarin prescribing and monitoring practices, and use of interacting medications.ResultsOver a 12 month period (28,555 resident-days, 78.2 resident years) 3065 INR values were available. Residents were within, below and above the therapeutic range 54%, 35% and 11% of the time, respectively. Seventy-nine percent of residents were prescribed at least one warfarin-interacting medication during the period in review. Residents receiving interacting medications spent less time in the therapeutic range (53.0% vs. 58.2%, OR = 0.93, 95% confidence interval 0.88 to 0.97, P = 0.002). Adequacy of anticoagulation varied significantly between physicians (time in therapeutic range 45.9 to 63.9%).ConclusionIn this group of long-term care residents, warfarin control was suboptimal. Both prescriber and co-prescription of interacting medications were associated with poorer INR control. Future studies should seek strategies to improve prescriber skill and decrease use of interacting medications.

Safety of Diagnostic Coronary Angiography During Uninterrupted Therapeutic Warfarin Treatment

Long-term warfarin therapy is assumed to increase bleeding and access site complications after coronary angiography and it is often recommended to postpone invasive procedures to reach international normalized ratio (INR) levels <1.8. To assess the safety and feasibility of diagnostic coronary angiography during uninterrupted warfarin therapy, we retrospectively analyzed all consecutive patients (n = 258) on warfarin therapy referred for diagnostic coronary angiography in 2 centers with long experience in uninterrupted warfarin therapy during coronary angiography and in 1 center with a policy of preprocedural warfarin pause. An age- and gender-matched control group (n = 258) with similar disease presentation (unstable or stable symptoms) was collected from each center. Radial access was used in 56% of patients in the warfarin group and in 60% of controls (p = 0.21). There was no difference in access site and bleeding complications (1.9% vs 1.6%) or major adverse cardiovascular and cerebrovascular events (0.4% vs 0.8%) between the warfarin group and their controls. Warfarin was interrupted in 80 patients (31%), and bridging therapy was used in 24 of these patients (30%). INR levels were higher in the uninterrupted warfarin group (2.3 vs 1.9, p <0.001), but the incidence of access site complications was not higher (1.7%) than in patients (n = 80) with a warfarin pause (2.5%) or in patients with pause and bridging therapy (8.3%). Need for blood transfusions (n = 2) occurred only in patients with bridging therapy. Access site complications were more common in the 22 patients with supratherapeutic anticoagulation (INR >3) than in patients with therapeutic periprocedural INR (9.1% vs 1.5%, p <0.05). In conclusion, a simple strategy of performing coronary angiography during uninterrupted therapeutic warfarin anticoagulation is a tempting alternative to bridging therapy and is likely to lead to considerable cost savings.

Effects of INR Levels on Bleeding Occurrences During the First 24-hours of Ultrasound Guided PICC Line Insertions

A sample of 127 patients with an International Normalized Ratio (INR) of 1.5 or greater, undergoing a Peripherally Inserted Central Catheter (PICC) insertion, were observed for bleeding at the time of insertion and for 24 hours post insertion. Over 60% of patients experienced no or mild bleeding at insertion. For an INR less than 3.0, fewer than 10% of the sample experienced moderate bleeding within the first 24 hours. No PICCs were discontinued due to bleeding. Results suggest that INR levels below 3.0 did not appear to have an impact on amount of bleeding during PICC insertion. After 24 hours, INR levels of 3.0 and above did appear to have an impact on the amount of bleeding.

Suturing extraction sockets on patients maintained on oral anticoagulants

A randomised controlled trial (RCT) was carried out. Patients scheduled for dental extraction were randomly divided into four groups: no suturing with either discontinued anticoagulants (group 1) or continued warfarin (group 2); and suturing with either discontinued anticoagulants (group 3) or continued warfarin (group 4). The international normalised ratio (INR) was determined at different timepoints (baseline, days 1, 3 and 7). The status of bleeding and healing were assessed by an independent examiner blinded to the treatment protocol for the four treatment groups. Discontinuing warfarin reduced INR level significantly at day 1, and it subsequently reached <1.5 in 96 out of 104 patients (groups 1 and 3). Statistical comparisons between the different treatment groups did not reveal any significant difference regarding bleeding status or healing pattern. Interestingly, patients who received sutures showed a higher but insignificant incidence of bleeding postoperatively compared with their respective controls. Dental extractions may be safely performed for people who are taking anticoagulation therapy provided the INR level is kept >/=3.0 and effective measures of local haemostasis are administered. The decision to suture should be made on a case-by-case basis, as the trauma associated with soft tissue handling might outweigh its advantages in some situations, such as simple extractions.

Excessive prolongation of prothrombin time among patients treated with warfarin and admitted to the emergency room

Introduction Patients treated with warfarin are uncommonly admitted with excessive prolongation of international normalized ratio (INR) of prothrombin time (PT) to the emergency room (ER). Here we wanted to evaluate the reasons behind this prolongation, clinical and laboratory parameters, course and outcome of these patients. Patients and methods Consecutive patients admitted to the ER with prolonged PT-INR > 6 under warfarin treatment and who gave sufficient information regarding history of warfarin treatment, were followed prospectively. Patients or care-givers were asked about warfarin treatment, PT monitoring, current and new medications especially antibiotics and diet. Clinical and laboratory parameters, course and outcome were also documented. Age and gender matched patients with therapeutic INR level were used as a control group. Results 75 patients finished the study. The median INR level among the patients was 8.5 and a range of 6.1–59.5. The median duration of warfarin treatment was 12 months among the patients vs. 36 in the control group, p < 0.001 and family physician was the sole decider on warfarin dose in 71 patients vs. 49 in the control group, p < 0.100. 19 patients adhered to balanced diet vs. 34 in the control group, p = 0.01. Dose increment of warfarin was the most common definite cause of prolonged PT followed by adding new medication especially amiodarone and recently started warfarin. Significantly more patients had evidence of bleeding than the control group but no difference in mean hemoglobin level or number of patients transfused with packed cells. No difference in the number of patients hospitalized or duration of hospitalization, but 5 in-hospital fatalities in the patients' group vs. none in the control group. Conclusion Excessive PT prolongation is mainly due to warfarin dose increment, adding new medication especially amiodarone and recently started warfarin. It is significantly more associated with bleeding and higher in-hospital mortality.

Perioperative international normalized ratio level is a poor predictor of postoperative bleeding complications in dermatological surgery patients taking warfarin

When planning dermatological surgery with patients on warfarin, clinicians must balance the risk of bleeding complications against that of a thrombotic event if anticoagulation is interrupted. To evaluate the frequency of bleeding complications in warfarinized subjects undergoing cutaneous surgery, and to correlate the risk of bleeding with the international normalized ratio (INR) at the time of surgery. In this prospective controlled observational study, 65 patients on warfarin underwent excision of 70 cutaneous tumours. Mean perioperative INR was 2.1 (range 1.0-4.2). A group of 92 nonwarfarinized controls underwent excision of 100 tumours by the same surgeons. The INR of those on warfarin was checked at the time of surgery. Intraoperative and postoperative bleeding was recorded by the operating surgeon. No increase in bleeding tendency during surgery was seen in those on warfarin when compared with controls. Five patients on warfarin (8%) reported moderate or severe postoperative bleeding. No significant postoperative bleeding was reported by controls (P=0.01). All patients on warfarin with bleeding complications had an INR of <2.6 at the time of surgery. Bleeding risk could not be correlated with INR and this study demonstrates that even when INR is in the therapeutic range the risk of postoperative bleeding is increased for warfarinized patients. The need for meticulous haemostasis in all patients on warfarin should not be forgotten and patients should be made aware preoperatively of the small but significant risk of postoperative bleeding complications.

The quality of anticoagulation on functional outcome and mortality for TIA/stroke in atrial fibrillation patients

BackgroundIn atrial fibrillation (AF) patients stroke is nearly twice as likely to be fatal as non-AF patients and functional deficits are more likely to be severe among survivors. The incidence of stroke among AF patients is greatly reduced by oral anticoagulant treatment (OAT). However, fluctuation of anticoagulation levels is intrinsically related to OAT and often international normalized ratio (INR) is out of the therapeutic range. MethodsSince the “anticoagulation history” is an ongoing process, we performed this prospective study in 578 AF patients to investigate the role of the whole quality of OAT and of INR levels at the occurrence of transient ischemic attack (TIA) or stroke on the severity of cerebral ischemia. ResultsDuring follow-up 13 patients had TIA and 18 had stroke (rate 1.67×100 pt/years). In relation to the quality of anticoagulant treatment, no significant differences were found in the time spent below and within the intended therapeutic range, between patients with and without TIA/stroke. Patients with TIA/stroke spent a longer time above the intended therapeutic range with respect to other patients, even if this difference was not confirmed at multivariate analysis. Forty-six percent of patients with TIA and 66% of patients with stroke had INR≥2 at the occurrence of ischemic event. ConclusionThe severity of stroke was not related to the whole quality of anticoagulation or to INR at the event.

Effect of methimazole on warfarin anticoagulation in a case of Graves' disease

The article describes a case of Graves' disease treated with methimazole and examines the influence of methimazole-induced alterations of thyroid hormone concentrations during warfarin therapy. A 22-year-old woman presented at our endocrinology outpatient clinic with palpitations, sweating, fatigue, tremors, and diarrhea. She had a pain in her right leg and had difficulty walking. Her thyroid profile was consistent with hyperthyroidism. The patient was treated with warfarin 5 mg once a day for deep vein thrombosis for 2 days. Since a therapeutic range of International Normalized Ratio levels could not be achieved, methimazole was stopped due to drug-drug interaction. Lithium was started instead. A euthyroid state was obtained in 2 weeks together with a therapeutic International Normalized Ratio level. Interactions between warfarin and drugs that alter thyroid hormone concentrations have been reported; however, the extent and significance of the interaction between methimazole and warfarin have been inadequately described. Concomitant therapy with warfarin and antithyroid drugs should be managed by frequent monitoring of both thyroid function and the International Normalized Ratio. Lithium is employed only to provide temporary control of thyrotoxicosis in patients who cannot take thionamide and iodide. The administration of lithium alone or in combination with other drugs is shown to be an effective method of controlling hyperthyroidism when conventional antithyroid drugs show adverse effects or become insufficient. When warfarins are used together with antithyroid medications, adequate anticoagulation may not be obtained due to drug-drug interactions. Lithium can be an alternative drug for antithyroid medication in patients on warfarin therapy.

Risk factors of vitamin K antagonist overcoagulation

The aims of this case-control study were to identify in vitamin K antagonist (VKA)-treated unselected patients, factors associated with international normalised ratio (INR) values: (i) greater than 6.0.; and (ii) ranging from 4.0 to 6.0 complicated with bleeding. We also assessed VKA-related morbidity in these patients. During a two-month period, 4,188 consecutive and unselected patients were referred to our Emergency Department. At admission, the medical records of each patient and two age- and sex-matched controls were reviewed for: both duration and indication of VKA therapy, previous medical history of VKA-related haemorrhage, underlying co-morbidities, concomitant medications other than VKA, duration of hospitalization and deaths' causes. Of these 4,188 subjects, 50 case-patients (1.19%) were identified; both case-patients and controls did not differ as regards indications and patterns of VKA therapy. Interestingly, two-thirds of case-patients were women, suggesting that female gender may be a risk factor of VKA over-coagulation onset. We identified the following risk factors of VKA over-coagulation: previous medical history of INR levels over therapeutic range, therapy with antibiotics, amiodarone and proton pump inhibitors, as well as fever. A total of 88% of case-patients were hospitalized; mean duration of patients' hospitalization was seven days [range: 1-56 days]; no patient died from major bleeding. Our study underscores that it is of utmost importance to consider the strength of indication before starting VKA therapy, as this therapy has been responsible for as high as 1.19% of admissions in unselected subjects referred to an Emergency Department. Our data therefore suggest that internists should be aware of VKA-related high morbidity, particularly in situations at risk of VKA over-coagulation.

Postoperative bleeding and oral anticoagulants

Objective To examine the consequences of temporary withdrawal of warfarin and/or suturing on bleeding and healing pattern following dental extractions. Methods Two hundred and fourteen patients on long-term oral anticoagulation (warfarin) therapy scheduled for dental extraction were randomly divided into four groups: no suturing and discontinued (group 1) or continued warfarin (group 2), and suturing and discontinued (group 3) or continued warfarin (group 4). International normalised ratio (INR) was determined at different time points (baseline, days 1, 3 and 7). Results Discontinuing warfarin reduced INR level significantly at day 1, which subsequently reached <1.5 in 96 out of 104 patients (group 1 and 3). Statistical comparisons among the different treatment groups did not reveal any significant difference regarding bleeding status or healing pattern. Interestingly, patients who received sutures showed higher but insignificant incidence of bleeding postoperatively compared to their respective controls. Conclusion Dental extractions may be safely performed for patients on anticoagulation therapy provided the INR level is kept ≤ 3.0 and effective measures of local haemostasis are administered. The decision to suture should be made on case-by-case basis, as the trauma associated with soft tissue handling might outweigh its advantages in certain situations like simple extractions.

Evaluation of dental extractions, suturing and INR on postoperative bleeding of patients maintained on oral anticoagulant therapy

To examine the consequences of temporary withdrawal of warfarin and/or suturing on bleeding and healing pattern following dental extractions. Two hundred and fourteen patients on long-term oral anticoagulation (warfarin) therapy scheduled for dental extraction were randomly divided into four groups: no suturing and discontinued (group 1) or continued warfarin (group 2), and suturing and discontinued (group 3) or continued warfarin (group 4). International normalised ratio (INR) was determined at different time points (baseline, days 1, 3 and 7). Discontinuing warfarin reduced INR level significantly at day 1, which subsequently reached <1.5 in 96 out of 104 patients (group 1 and 3). Statistical comparisons among the different treatment groups did not reveal any significant difference regarding bleeding status or healing pattern. Interestingly, patients who received sutures showed higher but insignificant incidence of bleeding postoperatively compared to their respective controls. Dental extractions may be safely performed for patients on anticoagulation therapy provided the INR level is kept <3.0 and effective measures of local haemostasis are administered. The decision to suture should be made on case-by-case basis, as the trauma associated with soft tissue handling might outweigh its advantages in certain situations like simple extractions.

An economic model of adverse events and costs for oral anticoagulants used for atrial fibrillation

ABSTRACTObjective: To construct a semi-Markov model to compare health outcomes and medical costs associated with warfarin and a second anticoagulant over 1- and 5-year periods.Design: We posited a hypothetical cohort of 10 000 identical 70-year-old patients with atrial fibrillation. We posited 20 scenarios for events that included four possibilities for ischemic strokes (mild, moderate, severe, death) and 16 possibilities for hemorrhages. The model allowed for four levels of International Normalized Ratio. Event rates were based on outcomes in clinical trials and observational studies. Costs were estimated from the perspective of the third-party payer.Results: The greatest cost-generating events were virtually the same for the two drugs and included severe stroke ($1 758 548 for 1 year for both drugs), moderate stroke ($380 355 for 1 year for both drugs), and severe lower gastrointestinal (GI) hemorrhage ($193 804 for 1 year for warfarin and $193 474 for second drug). The least costly events for both drugs were mild intracranial or intracerebral hemorrhage ($7584 for warfarin and $4314 for second drug) and fatal upper GI hemorrhage ($16 781 and $16 752). Total costs for adverse events over 5 years were similar: $18 330 662 for warfarin and $17 102 847 for the second drug. Fatalities for 5 years were 123 for warfarin and 101 for the non-warfarin drug. Varying assumptions for nursing home care and numbers of ischemic strokes and hemorrhages generated the widest variation in costs.Limitations: We did not account for out-of-pocket expenses, ‘pain and suffering’ costs, or variation across practice settings.Conclusions: There was substantial variation in numbers and costs of adverse events across 20 scenarios, and for fatalities between the two drugs, but variation in costs between the two drugs was modest.

Acute Coronary Embolism without Valve Thrombosis in a Patient with a Prosthetic Mitral Valve—Successful Percutaneous Coronary Intervention: A Case Report

We present a 44-year-old female patient with anterior myocardial infarction caused by embolization from mitral valve prosthesis due to inadequate anticoagulation. The patient underwent a cardiac catheterization within the 1st hour of arrival. The angiography showed total occlusion of the left anterior descending coronary artery after the second diagonal branch. Percutaneous transluminal coronary angioplasty and stenting were performed, and coronary artery perfusion was restored. The pain disappeared completely immediately after this intervention. Transthoracic echocardiography shortly after this intervention showed normal prosthetic valve function and no thrombus. Transesophageal echocardiography performed 2 days later revealed no thrombus at the prosthetic valve. In conclusion, this case demonstrated that coronary embolism may occur even without prosthetic valve thrombus or dysfunction with suboptimal International Normalized Ratio levels, and can be successfully treated with percutaneous transluminal coronary angioplasty and stenting.

Difference in examination of coagulation function in heparin anticoagulant therapy between point of care tests and automatic coagulation analyzer

To investigate the difference in coagulation screening in heparin anticoagulant therapy between dry-chemistry point of care tests (POCT) and automatic analyzer. Blood samples were collected from 44 patients with myocardial infarction or intracranial hemorrhage, 34 males aged 78 +/- 10 and 10 females aged 73 +/- 8, to undergo examination of prothrombin time (PT), international normalized ratio (INR), activated partial thromboplastin time (APTT), and fibrinogen (Fbg) by dry-chemistry methods with coagulation analyzers of the models CG02 and Hemochron Jr II. The levels of APTT of 30 patients were measured by the bedside with analyzers model Hemochron Jr II, after their anticoagulation samples underwent measurement of the plasma heparin activity with ACL Advance automatic coagulation analyzer; the APTT was determined with STA-R. The correlation coefficients of PT, INR, APTT, and Fbg between the CG02 and STA-R results were 0.945, 0.966, 0.662, and 0.977 respectively (all P < 0.05). However, t test showed that the levels of PT and INR between these 2 groups were not significant, and the differences in the levels of APTT and Fbg were significant (both P < 0.05). ACL Advance analyzer showed that the heparin activities of 30 samples were 172 approximately 1465 U/L, and the APTT values measured by Hemochron Jr II and STA-R were 87 s +/- 32 s and 90 s +/- 46 s (P < 0.01). Dry-chemistry POCT is not suitable to report the results of the same patient simultaneously with the automatic analyzer.