The Prevalence of Nontherapeutic and Dangerous International Normalized Ratios Among Patients Receiving Warfarin in the Emergency Department
ABSTRACT We determine the prevalence of nontherapeutic and coagulopathic international normalized ratios (INRs) among patients receiving warfarin and presenting to an emergency department (ED). As a secondary goal, we aim to determine whether a simple decision aid composed of physical examination and historical features could be predictive of INR greater than 5.
This was a prospective, observational study at 2 associated urban academic centers from February 2003 through May 2004, using a convenience sample of patients identified by direct questioning and contemporaneous medical record review in the ED as receiving long-term warfarin therapy. Inclusion criteria were warfarin therapy and self-reported compliance. Patients were enrolled by trained researchers. The primary outcome measure was the percentage of patients within appropriate therapeutic range for their condition according to accepted national guidelines. Descriptive statistics were used, and multivariate regression analysis was performed to identify associations.
One thousand nineteen patients were enrolled. INR values were obtained in 77% (782/1019) of patients. Of these patients, 72% (95% confidence interval 67% to 76%) were outside the desired range. Values were less than 2 in 43% of patients and greater than 3 in 29% of patients. INR greater than 5 was present in 11% (86/782) of patients, and 40% (34/86) of these patients exhibited gross bleeding. Emergency therapy was administered in 12% (96/782) of patients: fresh frozen plasma in 7% of patients, heparin in 5% of patients. Intracranial hemorrhage was found in 12 patients, 5 with INR greater than 3. Ischemic stroke or venous thromboembolism occurred in 51 patients known to be receiving warfarin specifically for prevention of the event that occurred. Of these patients, 49% (25/51) had INR less than 2. Regression analysis indicated no sensitive or specific constellation of features, though 2 factors were associated with INR greater than 5: gross hemorrhage (P=.006) and increasing duration of therapy (P=.047).
The prevalence of undesirable INR in the ED is higher than in warfarin populations previously studied, and a significant number of nontherapeutic levels were associated with thromboembolism, stroke, or hemorrhage. Given the prevalence and established danger of subtherapeutic and supratherapeutic levels, a low threshold should be maintained for testing and addressing INR levels in patients receiving warfarin in the ED.
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ABSTRACT: Although therapeutic drug monitoring is not required for patients receiving dabigatran to determine therapeutic efficacy, there are a number of other factors to consider. Currently, there are no studies evaluating pharmacist-led management of dabigatran. The role of inpatient pharmacists related to the management of dabigatran was evaluated. All adult patients who received at least 1 dose of dabigatran with a length of stay greater than 24 hours in a single-center, community hospital between May 2011 and August 2012 were retrospectively reviewed (n = 176). Almost half of the patients (46%) required pharmacist intervention related to dabigatran management during hospital admission. Of patients receiving dabigatran prior to hospital admission, 18.4% were admitted on an inappropriate home dose. Transitioning between dabigatran and alternative anticoagulants accounted for the majority of pharmacist interventions (74.2%), with patients transitioning from unfractionated heparin to dabigatran occurring most frequently. Renal impairment requiring dose adjustment or drug discontinuation occurred in 6.3% of patients, whereas 6.8% of patients required pharmacist intervention for procedural anticoagulation. Inpatient therapy was determined to be relatively safe, with few patients (1.7%) requiring permanent discontinuation of dabigatran as a result of a bleeding complication. Pharmacists significantly contributed to the safe and appropriate use of dabigatran during hospitalization.Annals of Pharmacotherapy 10/2013; 47(12). DOI:10.1177/1060028013508643 · 2.92 Impact Factor
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ABSTRACT: This case highlights the fact that Supratherapeutic INRs direct the attention of the treating physicians' team to the underlying severely debilitating gastrointestinal diseases. Prolonged fasting or starvation reduces vitamin K levels. Such patients are more sensitive to treatment with Vitamin K antagonist-based anticoagulants. Hence, the Supratherapeutic INR can be an objective indicator of chronic loss of appetite with poor nutritional status of the patient and therefore acts as a warning sign for diagnosis of severe debilitating primary gastrointestinal disease.05/2011; 1(2):e21. DOI:10.4081/cp.2011.e21
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ABSTRACT: Aims: To describe the characteristics, treatment, and mortality in patients with ST-elevation myocardial infarction (STEMI) by use of chronic oral anticoagulant (OAC) therapy. Methods: Using data from the Global Registry of Acute Coronary Syndromes (GRACE), patient characteristics, treatment, and reperfusion strategies of STEMI patients on chronic OAC (‘OAC users’) are described, and relevant variables compared with patients not on chronic OAC (‘OAC non-users’). Six-month post-discharge mortality rates were evaluated by Cox proportional hazard models. Results: Of 19 094 patients with STEMI, 574 (3.0%) were on chronic OAC at admission. Compared with OAC non-users, OAC users: were older (mean age 73 vs. 65 years) and more likely to be female (37% vs. 29%); were more likely to have a history of atrial fibrillation, prosthetic heart valve, venous thromboembolism, or stroke/transient ischaemic attack; had a higher mean GRACE risk score (166 vs. 145); were less likely to be Killip class I (68% vs. 82%); and were less likely to undergo catheterization/percutaneous coronary intervention (52% vs. 66%, respectively). Of the patients who underwent catheterization, fewer OAC users had the procedure done within 24 h of admission (56.5% vs. 64.5% of OAC non-users). In propensity-matched analyses (n=606) rates of in-hospital major bleeding and in-hospital and 6-month post-discharge mortality were similar for OAC and OAC non-users (2.7% and 3.7%, P=0.64; 15% and 13%, p=0.56; 15% and 12%, p=0.47, respectively); rates of in-hospital recurrent myocardial infarction (8.6% and 2.0%, p<0.001) and atrial fibrillation (32% and 22%, p=0.004) were higher in OAC patients, while rates of 6-month stroke were lower (0.6% and 4.3%, p=0.038). Patients in both groups who underwent catheterization had lower mortality than those who did not undergo catheterization. Conclusion: This is the largest study to describe the characteristics and treatment of STEMI patients on chronic OAC. The findings suggest that patients on chronic OAC are less likely to receive guideline-indicated management, but have similar adjusted rates of in-hospital and 6-month mortality.09/2013; 2(3):280. DOI:10.1177/2048872613483019