SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
BACKGROUND: Several studies have demonstrated that patient self-management of oral anticoagulant therapy (OAT) can improve treatment quality. However, most of these studies were not conducted within a specialized anticoagulation care system. The objective of the present study was to determine whether patient self-management of OAT improves the quality of care delivered by anticoagulation clinics. METHODS: In this randomized study by 2 Dutch anticoagulation clinics 341 patients aged between 18 and 75 years and receiving long-term OAT were divided into 4 groups: an existing routine care group of patients untrained in self-management; a routine care group of trained patients; a group managed weekly at an anticoagulation clinic where international normalized ratios were measured by trained patients; and weekly patient self-management. A 2-step randomization procedure was followed: first, a Zelen-design randomization was performed to distribute patients (without informing them) to the existing care group or to receive training in self-management; second, trained patients were randomized to the 3 other study groups. RESULTS: Only 25.6% of invited patients agreed to participate in the training program. Patients who remained in the existing care group were within the international normalized ratio target range 63.5% of the time. The type of coumarin taken was a major predicting factor of OAT quality. In all study groups phenprocoumon outperformed acenocoumarol by 11.6% (95% confidence interval [CI], 6.6%-16.5%). Weekly management with phenprocoumon led to a 6.5% improvement (95% CI, 0.0%-13.1%) in time in the international normalized ratio target range when patients were managed at an anticoagulation clinic and to an 8.7% improvement (95% CI, 1.6%-15.9%) when patients were self-managed. Weekly management with acenocoumarol did not improve the quality of OAT. CONCLUSION: With selected patients, the quality of OAT obtained through patient self-management is at least as high as that delivered by specialized physicians at anticoagulation clinics. Weekly management of OAT with long-acting phenprocoumon has to be preferred at anticoagulation clinics or, where possible, through patient self-management.
BACKGROUND: We aimed to determine the effect of excessive anticoagulation on morbidity and mortality in hospitalized patients with major anticoagulant-associated hemorrhage. METHODS: We prospectively identified 101 consecutive inpatients admitted to Brigham and Women's Hospital with major bleeding occurring during administration of warfarin sodium, unfractionated heparin (UFH), or low-molecular-weight heparin (LMWH). RESULTS: Fifty patients had excessive and 51 had nonexcessive anticoagulation. The overall mortality at 60 days was 26% (13/50) in the excessive group compared with 10% (5/51) in the nonexcessive group (P =.03). Excessive warfarin therapy was associated with an increased 60-day mortality (P =.049), in contrast to excessive anticoagulation with UFH or LMWH alone (P =.27) or UFH or LMWH as a "bridge" to warfarin therapy (P =.10). Multivariate regression identified excessive anticoagulation as an independent predictor of 60-day mortality (adjusted hazard ratio [HR], 4.17; 95% confidence interval [CI], 1.39-12.49; P =.01), along with intracranial hemorrhage (adjusted HR, 6.16; 95% CI, 1.75-21.67; P =.005) and active cancer (adjusted HR, 3.79; 95% CI, 1.13-12.70; P =.03). Excessive anticoagulation was also a significant predictor of the combined nonfatal end point of stroke, myocardial infarction, hypotension, critical anemia, and surgical or angiographic intervention at 30 days (HR, 2.17; 95% CI, 1.25-3.78; P =.006). CONCLUSION: In a cohort of patients with anticoagulation-associated hemorrhage, excessive anticoagulation contributed independently to increased morbidity and mortality.
CONTEXT: Control of oral anticoagulation therapy has been reported to often be inadequate. Previous retrospective investigations suggest that patients' self-adjustment of oral anticoagulants may lead to improved control. OBJECTIVE: To investigate the effects of patients' self-management of oral anticoagulation therapy on accuracy of control and measures of treatment-related quality of life. DESIGN: Randomized, single-blind, multicenter trial. SETTING AND PARTICIPANTS: A total of 179 patients receiving long-term oral anticoagulation treatment were enrolled at 5 referral centers in Germany. INTERVENTION: Patients were randomized to an oral anticoagulation self-management group based on a structured treatment and teaching program and international normalized ratio (INR) self-monitoring. The control group received conventional care as provided by family physicians, including referral to specialists if necessary. MAIN OUTCOME MEASURES: Deviation of INR values from the individual INR target range (squared) and the 5 categories of treatment-related quality of life. RESULTS: Deviation of INR value from the mean of the INR target range was significantly lower in the intervention group at 3-month (squared INR deviation, 0.59 vs 0.95; P<.001) and 6-month follow-up (0.65 vs 0.83; P=.03) compared with the control group. Also, the intervention group had INR values within the target range more often (repeated measurement analysis for categorical data, P=.006). The results were mainly due to less frequent suboptimal INR values in the intervention group (32.8% vs 50.0% [P=.03] at 3-month, and 33.7% vs 48.2% [P=.08] at 6-month follow-up). Treatment-related quality-of-life measures, especially treatment satisfaction scores, were significantly higher in the intervention group compared with controls. CONCLUSIONS: An anticoagulation education program that includes self-management of anticoagulation therapy results in improved accuracy of anticoagulation control and in treatment-related quality-of-life measures. Further studies are needed to describe whether the program will reduce risk of bleeding or thromboembolism.
PURPOSE: This study was performed to assess the extent of bleeding in anticoagulated patients undergoing minor oral surgery procedures when compared with patients who stop their anticoagulation regimen before surgery and patients who have never been anticoagulated. MATERIALS AND METHODS: Patients on anticoagulant medications undergoing dentoalveolar surgery procedures either stopped their anticoagulation regimen 72 to 96 hours before the planned surgical intervention or continued their regular regimen throughout the time of surgery. Blood loss was measured by weighing sponges used in the procedures, and groups were compared for differences in blood loss. They were also compared with an additional control group that had never been on anticoagulant therapy. RESULTS: There was no difference in blood loss detected among any of the experimental or control groups. No bleeding complications occurred in any anticoagulated patient. CONCLUSIONS: The data suggest that many patients can safely undergo routine outpatient oral surgical procedures without alteration of their regular therapeutic anticoagulation regimens and without additional medical intervention. However, a larger experimental population may be needed to elucidate the appropriateness of this approach to perioperative care.
Risks and benefits of anticoagulant therapy depend directly of the quality of anticoagulation. We carried out a meta-analysis of published randomized trials to assess the overall effectiveness of computer-assisted prescription systems on the quality of anticoagulation. Randomized controlled trials were identified through electronic searches of the Medline database (1966-1997) and systematic analyses of the references of articles. Two investigators selected relevant papers and summarized data from the studies. The outcome variable was the proportion of days within the target range of anticoagulation. A pooled estimate of the common odds ratio of being in the target range and its confidence interval was obtained by the Mantel-Haenszel method. Nine trials having included 1336 patients were identified. Computer systems were based on a pharmacokinetic-pharmacodynamic model and a bayesian prediction method. Most of them concerned the oral anticoagulant warfarin. The global odds ratio of being in the target range was 1.29 [95% CI: 1.17-1.49], thus meaning that the use of a computer for anticoagulation optimization increased by 29% the proportion of visits where patients were appropriately treated. The proportion of clinical events was too low for allowing a summary analysis, but major hemorrhages tended to be less frequent among patients of the computer groups than among patients of the control groups (2.0 versus 3.9%). Evidence from randomized controlled trials supports the effectiveness of computer-aided anticoagulant prescription. Widespread use of these systems in ambulatory care could increase the benefit/risk ratio of anticoagulant treatment at a low cost.
BACKGROUND: Dual therapy with ticlopidine and aspirin has been shown to be as effective as or more effective than conventional anticoagulation in patients with an optimal result after implantation of intracoronary metallic stents. However, the safety and efficacy of antiplatelet therapy alone in an unselected population has not been evaluated. METHODS: Patients were randomized to conventional anticoagulation or to treatment with antiplatelet therapy alone. Indications for stenting were classified as elective (decided before the procedure) or unplanned (to salvage failed angioplasty or to optimize the results of balloon angioplasty). After stenting, patients received aspirin and either ticlopidine or conventional anticoagulation (heparin or oral anticoagulant). The primary end point was the occurrence of bleeding or peripheral vascular complications; secondary end points were cardiac events (death, infarction, or stent occlusion) and duration of hospitalization. RESULTS: In 13 centers, 236 patients were randomized to anticoagulation and 249 to antiplatelet therapy. Stenting was elective in 58% of patients and unplanned in 42%. Stent implantation was successfully achieved in 99% of patients. A primary end point occurred in 33 patients (13.5%) in the antiplatelet group and 48 patients (21%) in the anticoagulation group (odds ratio=0.6 [95% CI 0.36 to 0.98], P=0.03). Major cardiac-related events in electively stented patients were less common (odds ratio=0.23 [95% CI 0.05 to 0.91], P=0.01) in the antiplatelet group (3 of 123, 2.4%) than the anticoagulation group (11 of 111, 9.9%). Hospital stay was significantly shorter in the antiplatelet group (4.3+/-3.6 versus 6. 4+/-3.7 days, P=0.0001). CONCLUSIONS: Antiplatelet therapy after coronary stenting significantly reduced rates of bleeding and subacute stent occlusion compared with conventional anticoagulation.
OBJECTIVE: Risks and benefits of anticoagulant therapy depend directly of the quality of anticoagulation. We performed a meta-analysis of published randomized trials to assess the overall effectiveness of computer-based prescription systems on the quality of anticoagulation. DESIGN: Randomized controlled trials were identified through electronic searches of the Medline database (1966-1997) and systematic analyses of the references of articles. Two investigators selected relevant papers and summarized data from the studies. METHODS: The outcome variable was the proportion of days within the target range of anticoagulation. A pooled estimate of the common odds ratio of being in the target range and its confidence interval was obtained by the Mantel-Haenszel method. RESULTS: Seven trials having included 1217 patients were identified. Computer systems were based on a pharmacokinetic-pharmacodynamic model and a bayesian prediction method. Most of them concerned the oral anticoagulant warfarin. The global odds ratio of being in the target range was 1.58 [95% CI: 1.34-1.86], thus meaning that the use of a computer for anticoagulation optimization increased by 58% the proportion of visits where patients were appropriately treated. The proportion of clinical events was too low for allowing a summary analysis. CONCLUSION: Evidence from randomized controlled trials supports the effectiveness of computer-aided anticoagulant prescription. Diffusion of these systems in ambulatory care could increase the benefit/risk ratio of anticoagulant treatment at a low cost.
BACKGROUND: The indications for continuous oral anticoagulant treatment, the target interval and the procedures for withdrawing treatment have changed in the last 10 years. METHODS: Patients on continuous oral anticoagulant treatment at the Outpatient Anticoagulant Clinic at Umeå University Hospital in 2002 were included in a descriptive study (n = 900). 263 of those had a mechanical heart valve prosthesis. Only patient records for patients with other indications than mechanical heart valve prosthesis were examined. 582 of those records were found. In the 55 remaining patients some clinical information was retrieved from the computerised warfarin dosage database. These latter, more unsure clinical data, are presented separately. Anticoagulant treatment was discontinued if lack of proper indication or presence of too high risk for hemorrhagic complications were found. RESULTS: The prevalence of continuous oral anticoagulant treatment in the uptake area was 0.65%. The most common target interval was INR 2.1-3.0, but patients with a mechanical heart valve prosthesis were often treated more aggressively, i.e. with a higher INR target interval. Of the patients on continuous treatment, 26.6% of the INR values were outside 2.0-3.0. The most common reasons for oral anticoagulant treatment were atrial fibrillation or mechanical heart valve prosthesis, in contrast to earlier findings in studies of our population in 1987 and 1990. We found 90 patients (10.0%) without proper indication for oral anticoagulant treatment or too high risk, and their treatment was discontinued. CONCLUSION: In patients on oral anticoagulant therapy, re-evaluation of indications and risks resulted in a substantial number of treatment withdrawals. There have been major changes in treatment indications during the last decade, possibly due to rapid development of knowledge in the field of thrombosis risk factors. Treatment should be re-considered once a year.
BACKGROUND: Observations by pharmacists monitoring anticoagulated patients suggested that patients with diabetes often require more frequent international normalized ratio (INR) monitoring than patients without diabetes. The purpose of this investigation was to examine the association between glycemic control and therapeutic anticoagulation control. METHODS: Patients with diabetes who were receiving warfarin therapy monitored by the Kaiser Permanente of Colorado Clinical Pharmacy Anticoagulation Service were eligible for inclusion. Patients were included if they had a diagnosis of diabetes mellitus type 1 or 2, aged > or =18 years, and had initiated anticoagulant therapy > or =120 days before their most recent hemoglobin A1C measurement. The primary outcome was the correlation between hemoglobin A1C value and percent of time in the patient-specific INR range. Multivariate analysis was undertaken to regress percent of time in INR range on an A1C value > or =8.0 while adjusting for other possible explanatory variables. RESULTS: A total of 911 patients with diabetes were included in the study. Subjects with an A1C value > or =8.0 had similar characteristics as those subjects with an A1C value < 8.0. Correlation analysis revealed no relationship between percent of time spent in INR range and A1C value (Spearman Correlation Coefficient = 0.012, p = 0.805). Multivariate analysis revealed no relationship between percent of time spent in INR range and A1C value > or =8.0 (Odds Ratio = 1.00; 95% Confidence Interval = 0.99, 1.01) when adjusting for possible explanatory variables. CONCLUSIONS: For patients with diabetes on warfarin anticoagulation therapy, there is no association between glycemic control and therapeutic anticoagulation control. However, anticoagulation therapy providers should manage these patients with the same diligence and care as patients without diabetes.
The spontaneous anticoagulant-dependent platelet activation in vitro may potentially interfere with the determination of haemostatic parameters. The effects of various blood anticoagulants on platelet activation were monitored using flow cytometry. Regardless of a blood anticoagulant used (EDTAK2, heparin, citrate or PPACK), platelet activation began immediately after blood withdrawal and was most pronounced in the EDTAK2-anticoagulated blood samples. The progressing expression of GMP-140 antigen was accompanied by the enhanced abundance of the subunit beta 3 of the platelet membrane integrin alpha IIb beta 3 without parallel changes in the fluorescence attributed to the complex form of the integrin alpha IIb beta 3. The increased expression of GMP-140 was paralleled by the enhanced platelet clumping in the samples anticoagulated with either EDTAK2 or heparin, and the raised platelet microparticles in blood withdrawn into citrate. The EDTAK2-induced platelet activation was markedly reduced by methyl 2,5-dihydroxycinnamate, tyrosine kinase inhibitor. The influence of disodium EDTA on platelet membrane dynamics closely mimicked the alterations induced upon the interaction of fibrinogen with platelet GPIIb-IIIa. Thus, the EDTAK2-induced platelet activation might result from an interference with platelet membrane protein structure and conformation and possibly related to an "unspecific" trigerring of a signal transduction pathway. Overall, EDTAK2 and heparin appeared the least suitable anticoagulants, particularly with the regard to the expression of GMP-140 antigen. The failure to recognize the importance of a spontaneous anticoagulant-induced platelet activation may result in misdiagnoses during the monitoring of coagulation parameters.
OBJECTIVE: Anticoagulation therapy is an acceptable strategy for the prevention of thromboembolic events in the presence of atrial fibrillation. However, this strategy is controversial in older subjects particularly in the presence of dementia. We conducted an opinion poll regarding the decision to anticoagulate or not among physicians in practice and in various levels of training (residents and fellows) that was based on a specific, yet not unusual, case scenario in the nursing home. SETTING: A university teaching hospital in the Bronx, NY. METHODS: A survey questionnaire was distributed to physicians to solicit opinions on the decision to anticoagulate based on an actual case from a LTCF and the results were analyzed. RESULTS: One hundred seven completed surveys were returned from 49 residents, 20 fellows, and 38 attending physicians. The majority (85%) felt that long-term anticoagulation therapy was not indicated in the case patient. However, most (88%) felt they would provide an antiplatelet agent, with the choice being 78% aspirin, 20% clopridogel, and 2% aspirin-dipyridamole. The most cited reasons for not providing anticoagulation were risk of falls (98%), dementia (40%), and short life expectancy (32%). However, 92% of respondents felt that the patient was a candidate for short-term anticoagulation therapy. Interestingly, the choices (yes, no, uncertain) to the questions were similar for all physicians irrespective of their level of training or years in practice (or faculty) after training. CONCLUSIONS: Although long-term anticoagulation for thromboembolic events in atrial fibrillation is considered beneficial, recent reports suggest that warfarin is underused in older adults, especially in the long-term care setting. Our physician poll, based on a specific case scenario, is consistent with this opinion as reflected by both trainees and practicing physicians. While there are absolute and relative contraindications to the use of long-term warfarin, decisions should be individualized and based on risks, benefits, and quality of life of the resident.
The management of patients who require temporary interruption of oral anticoagulant therapy because of surgery or other invasive procedures is a clinically important topic because of the increasing prevalence of patients who are receiving oral anticoagulants and the availability of low-molecular-weight heparins (LMWHs), which allow out-of-hospital perioperative anticoagulation. The optimal management of such patients has been hampered by the lack of well-designed prospective studies investigating the efficacy and safety of different perioperative management strategies. The two main issues that need to be considered in perioperative anticoagulant management is the patient's risk of thromboembolic event when anticoagulant therapy is interrupted and the risk of bleeding that is associated with the surgery or procedure. An assessment of these factors will determine the perioperative management approach. The objectives of this review are to focus on practical issues relating to perioperative anticoagulation and the implementation of a perioperative anticoagulation management approach that can be used in everyday clinical practice.
Regional citrate anticoagulation should be a simple process of substituting hypertonic (1.6 mol/L) citrate for heparin and adjusting the infusion to obtain an arterial activated clotting time of 150 to 200 seconds. Serious, documented complications of citrate anticoagulation involve citrate intoxication during isolated ultrafiltration; hyperaluminemia, hyperammonemia, and hypernatremia during sorbent dialysis; and profound alkalosis, paresthesias, arrhythmia, and cardiac arrest during bicarbonate dialysis. We suspected that some of these complications could be avoided by using anticoagulant citrate dextrose-A (ACD) rather than hypertonic tri-sodium citrate (TSC) as the anticoagulant. In a cross-over study with random assignment order eight adults underwent mid-week dialyses with ACD (0.113 mol/L citrate) and TSC (1.6 mol/L citrate) regional citrate anticoagulation. Predialysis to postdialysis changes in Na (mEq/L), Ca (mg/dL), ionized Ca (mg/dL), pH, and HCO3 (mEq/L) are listed below. [Table in journal] Using continuous blood flow and avoiding isolated ultrafiltration and sorbent dialysis should prevent the delivery system complications of regional citrate anticoagulation. During this evaluation isotonic and hypertonic citrate resulted in similar serum sodium changes, and standard dialysate effectively reversed the citrate/calcium interaction of both hypertonic and isotonic citrate infusions to restore homeostasis without a separate calcium infusion. The combination of TSC and bicarbonate dialysate does produce a profound metabolic alkalosis, which is lessened by using ACD. In general, regional citrate anticoagulation is simplified by using standard dialysate with a hypertonic rather than an isotonic citrate infusion, and dangerous complications are further evaded by adjusting the dialysate bicarbonate to 25 to 30 mmol/L or substituting a mixture of citric acid and TSC (ACD) for TSC.