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Biomedical subjects

J D Douketis

Publications and source records attributed to J D Douketis.

At least 19 recordsLinked to original sources
PubMed2005

Brain natriuretic peptide in hemodynamically stable acute pulmonary embolism.

BACKGROUND: Controversy exists about the indication of thrombolytic therapy in the subgroup of hemodynamically stable patients with acute pulmonary embolism (PE) and right ventricular dysfunction. Brain natriuretic peptide (BNP) is excreted from the cardiac ventricles in response to cardiomyocyte stretch and can be measured with an easy-to-perform blood test. OBJECTIVE: The objective of this study was to determine the predictive value of elevated BNP levels for early recurrent venous thromboembolism with or without fatal outcome in hemodynamically stable patients with acute PE. In addition, we assessed the potential clinical consequences of initiating thrombolytic therapy based on the BNP levels alone. METHODS: A nested case-control study was performed within the framework of a large randomized-controlled trial totalling 2213 hemodynamically stable patients with confirmed acute, symptomatic PE. Ninety patients experienced a fatal or non-fatal recurrent venous thromboembolism during the first 3 months of follow-up (cases); Two hundred and ninety-seven patients with uneventful follow-up served as controls. Blood for BNP levels was obtained at referral and assayed in a central laboratory. RESULTS: Cases had significantly higher mean baseline BNP levels (P = 0.0002). The odds ratio (OR) for every logarithmic (log) unit increase in BNP concentration was 2.4 (95% CI: 1.5-3.7). A BNP cut-off level of 1.25 pmol L(-1) [the optimal point on the receiver-operating characteristic (ROC) curve] was associated with a sensitivity and specificity of 60% and 62%, respectively. In theory, for every patient correctly receiving thrombolytic therapy at this cut-off, 16 patients will receive this therapy unnecessarily. CONCLUSIONS: Brain natriuretic peptide level at presentation is significantly associated with early (fatal) recurrent venous thromboembolism in hemodynamically stable patients with acute PE. However, this relationship appears clinically insufficient to guide the initiation of thrombolytic therapy.

Acute Disease↗
PubMed2005

Systematic review of long-term weight loss studies in obese adults: clinical significance and applicability to clinical practice.

BACKGROUND: Obesity is a common health problem that requires a long-term care approach. We systematically reviewed long-term (> or =2 y) studies investigating dietary/lifestyle, pharmacologic, and surgical weight loss methods to assess (1) weight loss efficacy, defined by absolute weight loss and the proportion of subjects with > or =5% weight loss, (2) effects of weight loss on cardiovascular risk factors, and (3) applicability of findings from studies to everyday clinical practice. METHODS: The MEDLINE, HealthSTAR, and the Cochrane Controlled Trials databases were searched for studies investigating the long-term efficacy of weight loss methods in overweight and obese adults. Data were extracted for (i) weight loss after 1 y (pharmacologic studies only), 2 y, 3 y, and 4 y, (ii) proportion of subjects with > or =5% weight loss at the end of follow-up, and (iii) changes (end-of follow-up minus baseline values) in blood lipids, fasting blood glucose, and systolic and diastolic blood pressure. RESULTS: Dietary/lifestyle therapy provides <5 kg weight loss after 2-4 y, pharmacologic therapy provides 5-10 kg weight loss after 1-2 y, and surgical therapy provides 25-75 kg weight loss after 2-4 y. Weight loss of > or =5% baseline weight is not consistently associated with improvements in cardiovascular risk factors and these benefits appear to be intervention specific and occur mainly in people with concomitant cardiovascular risk factors. Weight loss studies have methodologic limitations that restrict the applicability of findings to unselected obese people assessed in everyday clinical practice. These limitations include an inadequate study duration, large proportions of subjects lost to follow-up, a lack of an appropriate usual care group, and a lack of reporting of outcomes in high-risk subgroups. CONCLUSIONS: Dietary/lifestyle and pharmacologic weight loss interventions provide modest weight loss, and may improve markers of cardiovascular risk factors although these benefits occur mainly in patients with cardiovascular risks. Studies investigating weight loss have methodologic limitations that restrict the applicability of findings to obese patients assessed in clinical practice.

Adolescent↗
PubMed2005

The incidence and prognostic significance of elevated cardiac troponins in patients with submassive pulmonary embolism.

Although the incidence and prognostic significance of elevated cardiac troponins are known in patients with massive pulmonary embolism (PE), few studies have addressed this issue in patients with hemodynamically stable, submassive PE, who comprise the majority of patients presenting with PE. This prospective cohort study was, therefore, designed to determine the incidence and prognostic significance of elevated cardiac troponins in patients with submassive PE. Consecutive patients with acute, symptomatic, submassive PE that was confirmed by objective diagnostic testing were studied. All patients received treatment with either unfractionated heparin or fondaparinux followed by a coumarin derivative and underwent clinical follow-up for 3 months. Cardiac troponin I (cTnI) levels were measured within 24 h of clinical presentation. An elevated cTnI was defined as > 0.5 microg L(-1) and indicated myocardial injury. Major myocardial injury, that is associated with myocardial infarction, was defined by a cTnI > 2.3 microg L(-1). The clinical outcomes were recurrent venous thromboembolism and all-cause death. In 458 patients with submassive PE, the incidence of cTnI > 0.5 microg L(-1) was 13.5%[95% confidence interval (CI): 10.4-16.7], and the incidence of cTnI > 2.3 microg L(-1) was 3.5% (95% CI: 2.0-5.6). An elevated cTnI > 0.5 microg L(-1) was associated with an increased risk of all-cause death [odds ratio (OR) = 3.5; 95% CI: 1.0-11.9], but did not appear to confer an increased risk of recurrent venous thromboembolism (OR = 1.1; 95% CI: 0.2-4.9). In patients who present with submassive PE, an elevated cTnI occurs in about one in seven patients and is associated with a 3.5-fold increased risk of all-cause death.

Aged↗
PubMed2005

Does the type of hormone replacement therapy influence the risk of deep vein thrombosis? A prospective case-control study.

BACKGROUND: Although hormone replacement therapy (HRT) is associated with an increased risk of deep vein thrombosis (DVT), it is not clear if the risk differs in users of combined estrogen-progestin HRT and estrogen-only HRT. METHODS: We prospectively studied postmenopausal women with suspected DVT in whom HRT use status was ascertained and who subsequently had objective diagnostic testing to confirm or exclude DVT. Cases were patients with idiopathic DVT, in whom there were no DVT risk factors, and controls were patients without DVT, in whom there were also no DVT risk factors. The risk of DVT was determined in users of estrogen-progestin HRT and estrogen-only HRT by comparing the prevalence of current HRT use in cases with idiopathic DVT and controls without DVT (reference group). Multivariable regression analysis was done to adjust for factors that might confound an association between HRT use and the risk of DVT. RESULTS: One thousand one hundred and sixty-eight postmenopausal women with suspected DVT were assessed, from whom 95 cases of idiopathic DVT and 610 controls without DVT and no DVT risk factors were identified. Estrogen-only HRT was associated with an increased risk for DVT that was not statistically significant [odds ratio (OR) = 1.22; 95% confidence interval (CI) 0.57, 2.61]. Estrogen-progestin HRT was associated with a greater than 2-fold increased risk for DVT (OR = 2.70; 95% CI 1.44, 5.07). CONCLUSION: The risk of developing DVT may be higher in users of combined estrogen-progestin HRT than in users of estrogen-only HRT.

Aged↗
PubMed2001

Extended-duration prophylaxis against venous thromboembolism after total hip or knee replacement: a meta-analysis of the randomised trials.

BACKGROUND: The optimum duration of prophylaxis against venous thromboembolism after total hip or knee replacement is uncertain. Our primary objective was to establish the efficacy of extended-duration prophylaxis on symptomatic venous thromboembolic events. METHODS: We identified randomised trials comparing extended-duration prophylaxis using heparin or warfarin with placebo or untreated control in patients undergoing elective total hip or knee replacement by searching electronic databases (MEDLINE, EMBASE), references from retrieved articles, and abstracts from conference proceedings, and by contact with pharmaceutical companies and investigators. Two reviewers independently extracted data on study design, symptomatic and symptomless venographic venous thromboembolism, death, and bleeding outcomes. Results from individual trials were combined with the Mantel-Haenszel method. FINDINGS: Nine studies met our inclusion criteria (3999 patients), eight with low molecular weight heparin, and one with unfractionated heparin. Extended-duration prophylaxis for 30-42 days significantly reduced the frequency of symptomatic venous thromboembolism (1.3% vs 3.3%, OR 0.38; 95% CI 0.24-0.61, numbers needed to treat [NNT]=50), with no statistical evidence of heterogeneity (x(2) test, p=0.69). There was a greater risk reduction in patients undergoing hip replacement (1.4% vs 4.3%, 0.33; 0.19-0.56, 34) compared with knee replacement (1.0% vs 1.4%, 0.74; 0.26-2.15, 250). A significant reduction in symptomless venographic deep vein thrombosis was also observed (9.6% vs 19.6%, 0.48; 0.36-0.63, 10). There was no increase in major bleeding but extended-duration prophylaxis was associated with excess minor bleeding (3.7% vs 2.5%, 1.56; 1.08-2.26, numbers needed to harm [NNH]=83). INTERPRETATION: Among patients undergoing total hip or knee replacement, extended-duration prophylaxis significantly reduces the frequency of symptomatic venous thromboembolism. The reduction in risk is equivalent to about 20 symptomatic events per 1000 patients treated.

Anticoagulants↗
PubMed2001

Does the location of thrombosis determine the risk of disease recurrence in patients with proximal deep vein thrombosis?

PURPOSE: To determine if the location of deep vein thrombosis is a predictor of recurrent venous thromboembolism during the initial 3 months of anticoagulant therapy. METHODS: The study population consisted of 1,149 consecutive patients with symptomatic proximal deep vein thrombosis. In all patients, deep vein thrombosis was confirmed by Duplex ultrasound or venography and was classified as popliteal, femoral, or iliofemoral. Patients received initial treatment with unfractionated heparin, enoxaparin, or reviparin for least 4 days, as well as a coumarin derivative, with a target international normalized ratio of 2.0 to 3.0, starting on the 1st or 2nd day of treatment. All patients were followed for 3 months, and all episodes of recurrent venous thromboembolism were confirmed with objective diagnostic tests. RESULTS: The overall rate of recurrent venous thromboembolism during the initial 3 months of anticoagulant therapy was 5.5% (63/1,149). The rate of recurrence in patients with popliteal vein thrombosis was 5.1% (23/453); in patients with femoral vein thrombosis, it was 5.3% (34/645); and in patients with iliofemoral vein thrombosis, it was 11.8% (6/51). Two clinical risk factors were associated with an increased risk of recurrent venous thromboembolism: iliofemoral vein thrombosis (odds ratio [OR] = 2.4; 95% confidence interval [CI]: 0.95, 5.9), and cancer (OR = 2.6; 95% CI: 1.5, 4.4). CONCLUSIONS: Patients with extensive iliofemoral vein thrombosis who receive conventional anticoagulant therapy have a greater than twofold higher risk of developing recurrent venous thromboembolism than patients without iliac vein involvement (i.e., 11.8% vs. 5.2%). Prospective studies are needed to determine whether alternative antithrombotic strategies are warranted in such patients.

Anticoagulants↗
PubMed2001

Prognosis in pulmonary embolism.

Acute pulmonary embolism has a wide prognostic spectrum, ranging from sudden death within minutes of a thromboembolic episode to a benign treatable condition associated with a stable clinical course and no long-term sequelae. In patients who survive an initial thromboembolic episode and receive antithrombotic therapy, the clinical course can be complicated by recurrent nonfatal venous thromboembolism, fatal pulmonary embolism, the postthrombotic syndrome, and chronic thromboembolic pulmonary hypertension. Identifying which patients are at increased risk of experiencing these sequelae is important in decision making relating to the aggressiveness of initial antithrombotic therapy, the duration of antithrombotic therapy, and the frequency of clinical surveillance. In addition, this information may be helpful to clinicians in discussing disease prognosis with patients. The objectives of this review are to provide reasonable estimates of the risks of recurrent nonfatal venous thromboembolism, fatal pulmonary embolism, the postthrombotic syndrome, and chronic thromboembolic pulmonary hypertension in patients with treated pulmonary embolism, and to identify risk factors for these sequelae.

Biomarkers↗
PubMed2001

Treatment of warfarin-associated coagulopathy: a physician survey.

STUDY OBJECTIVES: (1) To determine physician preferences in the management of warfarin-induced excessive anticoagulation (AC); and (2) to assess compliance with the American College of Chest Physicians (ACCP) guidelines for the reversal of excessive AC. DESIGN: Cross-sectional physician survey. PARTICIPANTS: Members of the Canadian Society of Internal Medicine practicing in Ontario, Canada. MEASUREMENTS AND RESULTS: Physicians were asked to provide management preferences in six clinical scenarios describing warfarin-induced excessive AC. The scenarios represent various combinations of international normalized ratio (INR) value, treatment setting, and presence and severity of bleeding. In scenarios with INRs < 5.2 without bleeding, conservative approaches complying with the ACCP guidelines, such as withholding warfarin or reducing its dose, were most common. In scenarios with high INRs (ie, > 7.1) and/or bleeding, the selection of vitamin K in any form ranged between 71% and 82%. However, compliance with the ACCP-recommended doses and the routes of vitamin K administration ranged from 1 to 10%. In five of the six scenarios, subcutaneous injection, a route not recommended by the ACCP, was the most common method of vitamin K delivery. CONCLUSIONS: Physician preferences for the reversal of warfarin-induced excessive AC were highly variable and, in most cases, did not follow the recommendations of the ACCP consensus guidelines. Furthermore, the widespread reported use of subcutaneous vitamin K is concerning because this route of vitamin K administration has been demonstrated to be less effective than IV administration of vitamin K. These findings highlight the need for randomized controlled trials to compare the efficacy of different routes of administration of vitamin K for warfarin-associated coagulopathy.

Adult↗
PubMed2001

Patient self-monitoring of oral anticoagulant therapy: potential benefits and implications for clinical practice.

Coumarin derivatives are widely used oral anticoagulants for patients with chronic atrial fibrillation, venous thromboembolism, valvular heart disease, myocardial infarction or a mechanical prosthetic heart valve. Because of the narrow therapeutic window associated with coumarins and the potential for drug interactions, frequent monitoring of anticoagulation is required to maintain the International Normalized Ratio (INR) between 2.0 to 3.5 for most clinical indications. Monitoring of oral anticoagulant therapy is placing a considerable burden on healthcare providers because many patients require life-long treatment with coumarins, and because of an increasing number of elderly patients with conditions that are treated with coumarins. A novel approach that might, in part, address this healthcare need is patient self-monitoring of anticoagulation with a portable coagulometer. Several cohort studies and randomized controlled trials have found that anticoagulation self-monitoring is as good as, or better than, conventional monitoring in a specialized anticoagulation clinic or by a general practitioner. The advantages of anticoagulation self-monitoring include reduced patient inconvenience relating to anticoagulation clinic visits and laboratory monitoring of warfarin therapy, and fewer INR levels outside the therapeutic INR range if INR measurements are preformed more frequently with anticoagulation self-monitoring. Thus, anticoagulation self-monitoring has the potential to reduce the incidence of thromboembolic and bleeding episodes in patients who are receiving long term oral anticoagulant therapy. The potential drawbacks of anticoagulation self-monitoring include the costs of the portable coagulometer. Additionally, self-monitoring is limited to patients who have the cognitive and physical capabilities to perform the technique required for the portable coagulometer.

Administration, Oral↗
PubMed2001

Acute renal vein thrombosis, oral contraceptive use, and hyperhomocysteinemia.

Oral contraceptive use and hyperhomocysteinemia are considered to be relatively weak risk factors for venous thromboembolism. We report a case of acute renal vein thrombosis, a rare and aggressive form of thromboembolism, that occurred in a 21-year-old woman taking oral contraceptives, who was subsequently found to have marked hyperhomocysteinemia. This case suggests that the oral contraceptive and hyperhomocysteinemia may interact in a synergistic manner in the pathogenesis of thrombosis. In oral contraceptive users who develop venous thrombosis in the absence of other risk factors, clinicians should consider investigations for an underlying prothrombotic biochemical disorder.

Acute Disease↗
PubMed2000

The effects of hormone replacement therapy on thrombin generation, fibrinolysis inhibition, and resistance to activated protein C: prospective cohort study and review of literature.

Recent studies have found that hormone replacement therapy (HRT) is associated with a two- to fourfold increased risk of venous thromboembolism, but the thrombogenic mechanism of HRT remains unclear. To investigate whether HRT use induces a procoagulant state, we undertook a prospective cohort study in postmenopausal women to investigate the effects of 3 months of treatment with oral HRT (conjugated equine estrogen 0.625 mg daily and medroxyprogesterone 2.5 mg daily) on markers of thrombin generation (prothrombin fragment 1+2, thrombin-antithrombin complexes), fibrinolytic potential (plasminogen activator inhibitor-1 (PAI-1) activity), and activated protein C (APC) resistance. In addition, we reviewed the literature for studies investigating the effects of HRT on markers of thrombin generation and fibrinolytic potential. In 12 patients who received HRT for a mean of 3.8 months, there was no significant effect of HRT on levels of F1+2, thrombin-antithrombin complexes, or the APC ratio. HRT use had the greatest effect on PAI-1 activity (mean difference = -3.75 UI/mL; 95% confidence interval: - 8.9, 1.1) compared to other coagulation parameters, but this did not attain statistical significance (p = 0.12). In the literature review, the effects of HRT on markers of thrombin generation were inconsistent across studies. There was a consistent pattern of increased fibrinolytic potential with HRT use associated with one marker (PAI-1), but not with another marker (tissue plasminogen activator antigen). We conclude that there is a lack of consistent evidence that the increased risk of venous thromboembolism associated with HRT use is due to a procoagulant state related to increased thrombin generation, decreased fibrinolytic potential, or acquired APC resistance.

Activated Protein C Resistance↗
PubMed2000

A meta-analysis comparing low-molecular-weight heparins with unfractionated heparin in the treatment of venous thromboembolism: examining some unanswered questions regarding location of treatment, product type, and dosing frequency.

OBJECTIVES: To compare the efficacy and safety of unfractionated heparin (UFH) and low-molecular-weight heparins (LMWHs) and to examine current controversies in the treatment of venous thromboembolism (VTE) (ie, setting, product type, and frequency of administration). METHODS: Data were abstracted from MEDLINE, HEALTH, previous reviews, personal files, clinical experts, and conference abstracts. Randomized controlled trials of patients diagnosed with acute VTE that compared LMWHs with UFH were included. Independent duplicate assessment was done for methodological quality and data extraction. Data are reported as pooled relative risks (RRs) and 95% confidence intervals (CIs) comparing LMWHs with UFH as determined by the random effects model. RESULTS: Thirteen studies were included. There was no statistically significant difference in risk between UFH and LMWHs for recurrent VTE (RR, 0.85 [95% CI, 0.65-1.12]), pulmonary embolism (RR, 1.02 [95% CI, 0.64-1.62]), major bleeding (RR, 0.63 [95% CI, 0.37-1.05]), minor bleeding (RR, 1.18 [95% CI, 0.87-1.61]), and thrombocytopenia (RR, 0.85 [95% CI, 0.45-1.62]). There was a statistically significant difference for risk of total mortality (RR, 0.76 [95% CI, 0.59-0.98]) in favor of LMWHs. Inpatient treatment may reduce the risk of major bleeding vs outpatient therapy. Once-daily therapy is as safe and effective as twice-daily therapy when compared indirectly. Different products could not be statistically compared, but qualitative analysis shows that there are no apparent differences in efficacy and safety. CONCLUSIONS: Low-molecular-weight heparins are at least as effective as UFH in preventing recurrent VTE. It is unlikely that LMWHs are superior in the treatment of VTE, but they do show a statistically significant decrease in total mortality. No differences were seen in the development of recurrent VTE dependent on treatment setting. There were no apparent differences between once-daily and twice-daily therapy or among products. Inpatient therapy may be associated with less major bleeding; therefore, if LMWHs are given in the outpatient setting, patients should be rigorously monitored.

Anticoagulants↗
PubMed2000

Perioperative anticoagulation in patients with chronic atrial fibrillation who are undergoing elective surgery: results of a physician survey.

OBJECTIVE: To survey physicians' anticoagulation preferences in patients with chronic atrial fibrillation who are undergoing elective surgery. MATERIALS AND METHODS: A survey was performed that asked physicians to provide pre- and postoperative anticoagulation preferences for two clinical scenarios of patients with chronic atrial fibrillation (high stroke risk, low stroke risk) undergoing elective surgery. In addition to the interruption of warfarin therapy, perioperative anticoagulation options were as follows: a) in-hospital full dose intravenous heparin; b) outpatient full dose subcutaneous unfractionated heparin or low molecular weight heparin (LMWH); c) low dose unfractionated heparin or LMWH (postoperative only); d) nothing other than stopping warfarin preoperatively and restarting it postoperatively; or e) another anticoagulant strategy. RESULTS: In the high stroke risk scenario, the proportions of respondents preferring anticoagulation options a, b, d and e in the preoperative period were 24%, 20%, 54% and 2%, respectively; the proportions preferring options a, b, c, d and e in the postoperative period were 35%, 13%, 15%, 35% and 1%, respectively. In the low stroke risk scenario, the proportions of respondents preferring options a, b, d and e in the preoperative period were 7%, 10%, 80% and 3%, respectively; the proportions preferring options a, b, c, d and e in the postoperative period were 11%, 9%, 10%, 68% and 2%, respectively. CONCLUSIONS: In patients with chronic atrial fibrillation who underwent elective surgery, perioperative anticoagulant management preferences varied widely in patients at high risk for stroke, but were more uniform and less aggressive in patients at low risk for stroke.

Anticoagulants↗
PubMed1999

Periodic health examination, 1999 update: 1. Detection, prevention and treatment of obesity. Canadian Task Force on Preventive Health Care.

OBJECTIVES: (1) To evaluate the evidence relating to the effectiveness of methods to prevent and treat obesity, and (2) to provide recommendations for the prevention and treatment of obesity in adults aged 18 to 65 years and for the measurement of the body mass index (BMI) as part of a periodic health examination. OPTIONS: In adults with obesity (BMI greater than 27) management options include weight reduction, prevention of further weight gain or no intervention. OUTCOMES: The long-term (more than 2 years) effectiveness of (a) methods to prevent obesity and (b) methods to treat obesity. EVIDENCE: MEDLINE was searched for articles published from 1966 to April 1998 that related to the prevention and treatment of obesity; additional articles were identified from the bibliographies of review articles and the listings of Current Contents. Selection criteria were used to limit the analysis to prospective studies with at least 2 years' follow-up. BENEFITS, HARM AND COSTS: Health benefits of weight reduction were evaluated in terms of alleviation of symptoms, improved management of obesity-related diseases and a reduction in major clinical outcomes. The health risk of weight-reduction methods were briefly evaluated in terms of increased mortality and morbidity. VALUES: The recommendations of this report reflect the commitment of the Canadian Task Force on Preventive Health Care to provide a structured, evidence-based appraisal of whether a manoeuvre should be part of a periodic health examination. RECOMMENDATIONS: (1) PREVENTION: There is insufficient evidence to recommend in favour of or against community-based obesity prevention programs; however, because of considerable health risks associated with obesity and the limited long-term effectiveness of weight-reduction methods, the prevention of obesity should be a high priority for health care providers (grade C recommendation). (2) TREATMENT: (a) For obese adults without obesity-related diseases, there is insufficient evidence to recommend in favour of or against weight-reduction therapy because of a lack of evidence supporting the long-term effectiveness of weight-reduction methods (grade C recommendation); (b) for obese adults with obesity-related diseases (e.g., diabetes mellitus, hypertension), weight reduction is recommended because it can alleviate symptoms and reduce drug therapy requirements, at least in the short term (grade B recommendation). (3) Detection: (a) for people without obesity-related diseases, there is insufficient evidence to recommend the inclusion or exclusion of BMI measurement as part of a periodic health examination, and therefore BMI measurement is left to the discretion of individual health care providers (grade C recommendation); (b) for people with obesity-related diseases, BMI measurement is recommended because weight reduction should be considered with a BMI of more than 27 (grade B recommendation). VALIDATION: The findings of this analysis were reviewed through an iterative process by the members of the Canadian Task Force on Preventive Health Care. SPONSORS: The Canadian Task Force on Preventive Health Care is funded through a partnership between the Provincial and Territorial Ministries of Health and Health Canada.

Adolescent↗
PubMed1999

Physician preferences for perioperative anticoagulation in patients with a mechanical heart valve who are undergoing elective noncardiac surgery.

STUDY OBJECTIVE: To determine physicians' anticoagulation preferences in patients with a mechanical heart valve who are undergoing elective surgery, and to determine the effect of different risks of thromboembolism (TE) and postoperative bleeding on anticoagulation preferences. DESIGN: Mail survey of physicians who prescribe anticoagulant therapy. METHODS AND RESULTS: Physicians were asked to provide anticoagulation preferences in four clinical scenarios of patients with a mechanical heart valve who are undergoing elective surgery. Physicians were asked to select from three preoperative anticoagulation options (two aggressive, one less aggressive) and four postoperative anticoagulation options (two aggressive, two less aggressive). IV heparin was the most frequently selected anticoagulation option. Depending on the scenario, it was preferred by 39 to 79% of respondents for preoperative anticoagulation therapy, and by 44 to 84% of respondents for postoperative anticoagulant therapy. The risk of TE had a strong influence on anticoagulation preferences: more respondents preferred aggressive anticoagulant management in high-risk compared with low-risk TE scenarios (p < 0.001). Anticoagulation preferences were not influenced by the risk of bleeding: the proportion of respondents who preferred aggressive anticoagulant management did not differ in high-risk and low-risk bleeding scenarios (p > 0.05). Of respondents who preferred IV heparin for postoperative anticoagulation therapy, the risk of bleeding influenced the timing of heparin initiation: fewer respondents preferred early heparin initiation (within 12 h after surgery) in high-risk compared with low-risk bleeding scenarios (p < 0.01). CONCLUSIONS: (1) Preoperative and postoperative IV heparin were the most frequently selected anticoagulation options. (2) The risk of TE, but not the risk of bleeding, influenced the aggressiveness of anticoagulant management. (3) If IV heparin was selected, the risk of bleeding influenced the timing of heparin initiation.

Aged↗
PubMed1999

The effects of low-intensity warfarin on coagulation activation in patients with antiphospholipid antibodies and systemic lupus erythematosus.

The optimal intensity of oral anticoagulant therapy for the prevention of thromboembolism in patients with antiphospholipid antibodies (APLA) and systemic lupus erythematosus is controversial. Retrospective studies have suggested that patients with APLA are resistant to oral anticoagulant therapy, with a targeted International Normalization Ratio (INR) of 2.0 to 3.0, and that a higher intensity of anticoagulation (INR: 2.6 to 4.5) is required to prevent recurrent thromboembolism. To investigate if patients with APLA are resistant to the anticoagulant effect of low intensities of warfarin therapy, we performed a randomized trial in which 21 patients with APLA and systemic lupus erythematosus were allocated to receive one of three intensities of warfarin (INR: 1.1 to 1.4, 1.5 to 1.9 or 2.0 to 2.5) or placebo for four months. The main outcome was the effect of each intensity of warfarin therapy on prothrombin fragment 1+2 level (F1+2), that was used as a marker of coagulation activation. When F1+2 levels in patients allocated to the three warfarin intensities were compared to F1+2 levels in the placebo group, there was a statistically significant decrease (p<0.05) in the patient group receiving warfarin with a targeted INR of 2.0 to 2.5 at two, three and four months, and in the patient group with a targeted of INR 1.5 to 1.9 at three months. We conclude that in patients with APLA and systemic lupus erythematosus, warfarin therapy, with a targeted INR of 2.0 to 2.5, is effective in suppressing coagulation activation, and therefore, might be effective in preventing thromboembolism.

Adolescent↗