OBJECTIVE: Assessing the quality of anticoagulant (AC) treatment in primary health care with regard to safety. DESIGN: Surveys of patients on AC treatment during 1999. SETTING: Community health centres (CHCs) in the northeastern region of Stockholm County. SUBJECTS: Nine hundred and fifty-seven patients, from 16 CHCs. MAIN OUTCOME MEASURES: Rate of bleeding and thromboembolic events during AC treatment and rate of values within the recommended treatment interval. The reporting of prothrombin-time (PT) results changed during the year from PT values to international normalised ratio (INR). RESULTS: A total of 48 bleeding events in 44 patients were noted, i.e. 6.8 per 100 patient-years. Of these, ten were major bleedings, 1.4 per 100 patient-years, including three fatal bleedings, 0.4 per 100 patient-years. Six thrombo-embolic events were noted during treatment, i.e. 0.8 per 100 patient-years. Bleeding events were more common at INR values greater than 2.80 than at values of 2.80, [relative risk (RR) 3.30, 95% confidence interval 1.90-5.71]. Of all the noted PT values, 65% were within the recommended intervals (the most common being PT 15-25%) and of all noted INR values 60% (the most common being INR 2.1-3.0). No differences in the rate of bleeding or the number of thrombo-embolic events between the periods of PT and INR results were found. CONCLUSIONS: The rate of complications was low and AC treatment in primary health care seems to be as safe as in hospital clinics.
Patients receiving oral anticoagulants run a higher risk of cerebral hemorrhage with a poor outcome. Serotonin-modulating antidepressants (selective serotonin reuptake inhibitors [SSRIs], serotonin-norepinephrine reuptake inhibitors [SNRIs]) are frequently used in combination with warfarin, but it is unclear whether this combination of drugs influences outcome after primary intracerebral hemorrhage (PICH). The authors investigated case fatality in PICH among patients from a defined population who were receiving warfarin alone, with aspirin, or with serotonin-modulating antidepressants.
Nine hundred eighty-two subjects with PICH were derived from the population of Northern Ostrobothnia, Finland, for the years 1993-2008, and those with warfarin-associated PICH were eligible for analysis. Their hospital records were reviewed, and medication data were obtained from the national register of prescribed medicines. Kaplan-Meier survival curves were drawn to illustrate cumulative case fatality, and a Cox proportional-hazards analysis was performed to demonstrate predictors of death.
Of the 176 patients eligible for analysis, 17 had been taking aspirin and 19 had been taking SSRI/SNRI together with warfarin. The 30-day case fatality rates were 50.7%, 58.8%, and 78.9%, respectively, for those taking warfarin alone, with aspirin, or with SSRI/SNRI (p = 0.033, warfarin plus SSRI/SNRI compared with warfarin alone). Warfarin combined with SSRI/SNRI was a significant independent predictor of case fatality (adjusted HR 2.10, 95% CI 1.13-3.92, p = 0.019).
Concurrent use of warfarin and a serotonin-modulating antidepressant, relative to warfarin alone, seemed to increase the case fatality rate for PICH. This finding should be taken into account if hematoma evacuation is planned.
From the Department of Health Care Evaluation, Regionens Hus, Gothenburg, Sweden (S.B., B.P.); Department of Cardiology, Danderyd Hospital, Karolinska Institute, Stockholm, Sweden (L.F.); and Department of Molecular and Clinical Medicine/Cardiology, Sahlgrenska Academy, University of Gothenburg, Sweden (L.B.).
Atrial fibrillation (AF) is a major risk factor for ischemic stroke. This study aims to update the knowledge about AF and associated stroke risk and benefits of anticoagulation.
We extracted data from the hospital, specialized outpatient, and primary healthcare and drug registries in a Swedish region with 1.56 million residents. We identified all individuals who had received an AF diagnosis during the previous 5 years; all stroke events during 2010; and patients with AF aged =50 years who had received warfarin during 2009.
AF had been diagnosed in 38 446 subjects who were alive at the beginning of 2010 (prevalence of 3.2% in the adult [=20 years] population); ˜46% received warfarin therapy. In 2010, there were 4565 ischemic stroke events and 861 intracranial hemorrhages. AF had been diagnosed in 38% of ischemic events (=50% among those aged =80 years) and in 23% of intracranial hemorrhages. An AF diagnosis was often lacking in hospital discharge records after stroke events. Warfarin therapy was associated with an odds ratio of 0.50 (confidence interval, 0.43-0.57) for ischemic stroke and, despite an increased risk of intracranial hemorrhage, an odds ratio of 0.57 (confidence interval, 0.50-0.64) for the overall risk for stroke.
AF is more common than present guidelines suggest. The attributable risk of AF for ischemic stroke increases with age and is close to that of hypertension in individuals aged =80 years. Because a majority of patients with AF with increased risk for stroke had not received anticoagulation therapy, there is a large potential for improvement.
BACKGROUND: Pregnancy and puerperium are associated with an increased risk of venous thromboembolism. Low-molecular-weight heparin is the anticoagulant of choice in pregnant women because, unlike warfarin, it does not cross the placenta. However, there are limited data on the risk of adverse birth outcomes following use of low-molecular-weight heparin in pregnancy. PATIENTS AND METHODS: We performed a population-based cohort study to examine the safety of low-molecular-weight heparin use in pregnancy using data from the Pharmacoepidemiological Prescription Database, The Danish Medical Birth Registry and the Regional Hospital Discharge Registry in North Jutland County, Denmark. The birth outcomes in a cohort of 66 pregnant women treated with low-molecular-weight heparin between 1991-98 were compared with the birth outcomes of 17,259 pregnant women who did not receive any prescriptive drugs during pregnancy. RESULTS: No increased risk of malformations, low birth weight or stillbirth was found. However, an increased risk of pre-term delivery was found (odds ratio: 2.11, 95%, confidence interval: 0.96-4.65), which could reflect inherited thrombophilia as an indication of low-molecular-weight heparin. CONCLUSION: We have provided additional evidence of the safety of low-molecular-weight heparin use in pregnancy.
On average, patients receiving therapy with oral anticoagulants (OACs) in the community are in the therapeutic range only 55% of the time. Anticoagulation control strongly influences the risk of hemorrhagic and thromboembolic events in such patients. However, not all anticoagulation-associated events are attributable to poor anticoagulation control, nor do all hemorrhagic or thromboembolic events occur in anticoagulated patients.
Measure the proportion of serious hemorrhagic and thromboembolic events that would be avoided if anticoagulation control was perfect.
A retrospective cohort study of eastern Ontario using population-based administrative databases. Anticoagulation control was determined for each day of OAC exposure using linear interpolation. Incident hemorrhagic or thromboembolic hospitalizations for control and OAC patients were identified. Hemorrhages and thromboemboli in OAC patients were deemed to be avoidable if they occurred at international normalized ratios of > 3 and 183,000 patient-years of observation with 6,400 patient-years of OAC exposure. Anticoagulation control could be determined for 51.5% of OAC exposure time. Control patients had hemorrhagic and thromboembolic event rates of 1.8% and 1.5% per year, respectively. A total of 10,020 people were exposed to OACs, and spent 14.2% and 26.7% of the time, respectively, with excessively high and low anticoagulation intensity. Excessively high anticoagulation intensity explained 25.6% (95% confidence interval [CI], 19.4 to 31.7) and 2.0% (95% CI, 1.5 to 2.5) , respectively, of all serious hemorrhages in the anticoagulated and entire population. Excessively low anticoagulation intensity explained 11.1% (95% CI, 4.4 to 17.7) and 1.1% (95% CI, 0.7 to 1.6) of all thromboemboli, respectively.
Our study showed that extreme anticoagulation intensity significantly impacted the health of the population. Improving anticoagulation control will have significant effects on the incidence of serious hemorrhagic and thromboembolic events in the both the anticoagulated and entire populations.
Postoperative atrial fibrillation and atrial flutter (POAF) are the most common complications of cardiac surgery that require intervention or prolong intensive care unit and total hospital stay. For some patients, these tachyarrhythmias have important consequences including patient discomfort/anxiety, hemodynamic deterioration, cognitive impairment, thromboembolic events including stroke, exposure to the risks of antiarrhythmic treatments, longer hospital stay, and increased health care costs. We conclude that prevention of POAF is a worthwhile exercise and recommend that the dominant therapy for this purpose be ß-blocker therapy, especially the continuation of ß-blocker therapy that is already in place. When ß-blocker therapy is contraindicated, amiodarone prophylaxis is recommended. If both of these therapies are contraindicated, therapy with either intravenous magnesium or biatrial pacing is suggested. Patients at high risk of POAF may be considered for first-line amiodarone therapy, first-line sotalol therapy, or combination prophylactic therapy. The treatment of POAF may follow either a rate-control approach (with the dominant therapy being ß-blocking drugs) or a rhythm-control approach. Anticoagulation should be considered if persistent POAF lasts >72 hours and at the point of hospital discharge. The ongoing need for any POAF treatment (including anticoagulation) should be reconsidered 6-12 weeks after the surgical procedure.
The stroke rate in atrial fibrillation is 4.5% per year, with death or permanent disability in over half. The risk of stroke varies from under 1% to over 20% per year, related to the risk factors of congestive heart failure, hypertension, age, diabetes, and prior stroke or transient ischemic attack (TIA). Major bleeding with vitamin K antagonists varies from about 1% to over 12% per year and is related to a number of risk factors. The CHADS(2) index and the HAS-BLED score are useful schemata for the prediction of stroke and bleeding risks. Vitamin K antagonists reduce the risk of stroke by 64%, aspirin reduces it by 19%, and vitamin K antagonists reduce the risk of stroke by 39% when directly compared with aspirin. Dabigatran is superior to warfarin for stroke prevention and causes no increase in major bleeding. We recommend that all patients with atrial fibrillation or atrial flutter, whether paroxysmal, persistent, or permanent, should be stratified for the risk of stroke and for the risk of bleeding and that most should receive antithrombotic therapy. We make detailed recommendations as to the preferred agents in various types of patients and for the management of antithrombotic therapies in the common clinical settings of cardioversion, concomitant coronary artery disease, surgical or diagnostic procedures with a risk of major bleeding, and the occurrence of stroke or major bleeding. Alternatives to antithrombotic therapies are briefly discussed.
Cardioversion can rapidly and effectively restore sinus rhythm in patients with persistent atrial fibrillation. Since 2011 dabigatran has been available as an alternative to warfarin to prevent thromboembolic events in patients with non-valvular atrial fibrillation undergoing cardioversion. We studied time to cardioversion, risk of adverse events, and risk of readmission with atrial fibrillation after cardioversion according to anticoagulation therapy.
Through the nationwide Danish registries we included 1,230 oral anticoagulation naïve patients with first time non-valvular atrial fibrillation and first time cardioversion from 2011 to 2012; 37% in the dabigatran group (n = 456), and 63% in the warfarin group (n = 774). Median time to cardioversion was 4.0 (interquartile range [IQR] 2.9 to 6.5) and 6.9 (IQR 3.9 to 12.1) weeks in the dabigatran and warfarin groups respectively, and the adjusted odds ratio of cardioversion within the first 4 weeks was 2.3 (95% confidence interval [CI] 1.7 to 3.1) in favor of dabigatran. The cumulative incidence of composite endpoint of stroke, bleeding or death were 2.0% and 1.0% at 30 weeks in the warfarin and dabigatran groups respectively, with an adjusted hazard ratio of 1.33 (95% CI 0.33 to 5.42). Cumulative incidence of readmission with atrial fibrillation after 30 weeks were 9% and 11% in the warfarin and dabigatran groups, respectively, and an adjusted hazard ratio of 0.66 (95% CI 0.41 to 1.08).
Anticoagulation treatment with dabigatran allows shorter time to cardioversion for atrial fibrillation than warfarin, and appears to be an effective and safe alternative treatment strategy to warfarin.