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Background: Impedance plethysmography performed serially over a one-week period has been shown to be an effective diagnostic strategy for patients with clinically suspected acute deep-vein thrombosis. Compression ultrasonography has a high sensitivity and specificity for the detection of proximal-vein thrombosis. The clinical value of repeated ultrasonography in the management of symptomatic deep-vein thrombosis is unknown. Methods: We conducted a randomized trial in 985 consecutive outpatients with clinically suspected deep-vein thrombosis to compare the diagnostic value of serial impedance plethysmography (494 patients) and serial compression ultrasonography (491 patients). We compared the positive predictive values of both tests for the diagnosis of venous thrombosis, using contrast venography as a reference. The frequencies of venous thromboembolism during a six-month follow-up period were also compared in patients with repeatedly normal results in order to evaluate the safety of withholding anticoagulant therapy from such patients. Results: The positive predictive value of an abnormal ultrasonogram was 94 percent (95 percent confidence interval, 87 to 98 percent), whereas the predictive value of impedance plethysmography was 83 percent (95 percent confidence interval, 75 to 90 percent) (P = 0.02). In patients with repeatedly normal results, the incidence of venous thromboembolism during the six-month follow-up period was 1.5 percent (95 percent confidence interval, 0.5 to 3.3 percent) for serial compression ultrasonography, as compared with 2.5 percent (95 percent confidence interval, 1.2 to 4.6 percent) for serial impedance plethysmography. Conclusions: In making the diagnosis of deep-vein thrombosis in symptomatic outpatients, serial compression ultrasonography is preferable to impedance plethysmography, in view of its superior performance in detecting venous thrombosis. (N Engl J Med 1993;329:1365-9.) [ABSTRACT FROM AUTHOR]

Background: The aim of the current analysis was to identify independent predictors of the overall clinical outcome of patients with atrial fibrillation (AF), including both stroke/thromboembolism and/or major bleeding. Given the overlap between stroke and bleeding risk factors, a composite risk-stratification score for stroke/thromboembolism or bleeding could potentially be developed.Methods: We used data from the vitamin K antagonist (VKA) arm (n = 2,293; 65% men; mean age 70 ± 9 years) of the AMADEUS (Evaluating the Use of SR34006 Compared to Warfarin or Acenocoumarol in Patients With Atrial Fibrillation) trial, which was a multicenter, randomized, open-label noninferiority study that compared fixed-dose idraparinux with VKA in patients with AF. We defined two composite end points: end point 1 was the combination of stroke/thromboembolism or major bleeding; end point 2 was defined as the combination of stroke, systemic or venous embolism, myocardial infarction, cardiovascular death, or major bleeding.Results: The independent predictors for composite end point 1 were age (P = .014), previous stroke/transient ischemic attack (P = .049), aspirin use (P = .002), and time in therapeutic range (P = .007). For composite end point 2, similar predictors were evident, plus left ventricular dysfunction (P = .011). Based on the regression models, two novel composite risk-prediction scores were developed and were validated externally in a "real-world" cohort of 441 outpatients with AF receiving anticoagulation treatment. Both composite scores 1 and 2 demonstrated numerically higher discriminatory performance (area under the curve [AUC], 0.728; 95% CI, 0.659-0.798 and AUC, 0.707; 95% CI, 0.655-0.758, for end points 1 and 2, respectively) and a positive net reclassification when compared with currently used risk models (CHADS2 [congestive heart failure, hypertension, age ≥ 75 years, diabetes, prior stroke or transient ischemic attack], CHA2DS2VASc [cardiac failure or dysfunction, hypertension, age ≥ 75 years [doubled], diabetes, stroke (doubled)-vascular disease, age 65 to 74 years, and sex category (female)], and HAS-BLED [hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile international normalized ratio, elderly, drugs/alcohol concomitantly]), but the differences were not statistically significant.Conclusions: We have developed and validated two novel composite scores for stroke/thromboembolism/bleeding that offer good discriminatory and predictive performance. However, these composite risk scores did not perform better than the easier and more practical "traditional" stroke and bleeding risk scores that are currently in use, which allow greater practicality and a more personalized balancing of risks. [ABSTRACT FROM AUTHOR]

Background: Central venous catheters (CVCs) are used in a wide variety of patients. Associated complications are thrombosis and infection. It is a matter of debate whether thromboprophylaxis is beneficial. Methods: We performed a systematic review of 3 different patient populations to render the available information in the literature more accessible to clinical practice: patients receiving parenteral nutrition (PN), patients with cancer, and patients admitted to intensive care units. Results: Prophylaxis with heparin added to PN was found to give a nonsignificant reduction in the incidence of catheter-related thrombosis (pooled relative risk of randomized studies, 0.77; 95% confidence interval [CI], 0.11-5.48). In cancer patients, both low-dose warfarin and low-molecular-weight heparin significantly reduced the incidence of catheter-related thrombosis (relative risk of randomized studies, 0.25 [95% CI, 0.09-0.70] and 0.10 [95% CI, 0.01-0.71], respectively). So far, intensive care patients have hardly been studied with respect to thromboprophylaxis and the incidence of CVC thrombosis. Any effect of the type of catheter could not be established because of small numbers. There was no apparent increase in bleeding events with prophylactic anticoagulation in patients with CVCs. Conclusions: In the small number of patients studied, the addition of heparin to PN did not significantly decrease the risk of cathether-related thrombosis, whereas warfarin and dalteparin did decrease the thrombosis risk in cancer patients with CVCs. There is no apparent increase in bleeding events with prophylactic anticoagulants in patients with CVCs. [ABSTRACT FROM AUTHOR]

Venous thromboembolism (VTE) is a common complication in all types of cancer and adversely impacts cancer prognosis. Randomized controlled trials with primary thromboprophylaxis in cancer patients generally show effective VTE relative risk reductions of up to 60%. However, absolute risks of VTE were fairly low. Thromboprophylaxis should therefore only be recommended to cancer patients at highest risk of VTE, who may benefit most from prophylaxis. Predictive risk models to identify patients at a high risk of VTE are promising, however additional validation is required. An increasing proportion of cancer-associated VTE is formed by incidental VTE, with similar risk factors and clinical consequences. Randomized trials are not yet available, but it seems reasonable to treat incidental VTE similarly to symptomatic VTE. In a substantial proportion of patients with unprovoked VTE without known cancer at the time of VTE diagnosis, concomitant or occult cancer is identified. Studies have investigated the value of extensive screening over routine examinations alone for occult cancer. Although extensive screening may be able to identify more occult cancers, its clinical benefit over routine screening has not been demonstrated. [ABSTRACT FROM AUTHOR]

ABSTRACT: Background: In patients with suspected pulmonary embolism (PE), an unlikely or non-high probability assessment combined with a normal D-dimer test can safely exclude the diagnosis. We studied the influence of early D-dimer knowledge on clinical probability assessment. Methods: A questionnaire was sent to 150 randomly selected pulmonologists and internists in the Netherlands, presenting six hypothetical case-descriptions of patients with suspected PE. Physicians were randomized to receive one of three versions. The version contained a normal, an abnormal or no D-dimer result with each case-description. Each version contained two cases with an abnormal D-dimer result, two cases with a normal D-dimer result and two cases with no D-dimer result. Results: A total of 71 physicians (47%) returned the questionnaire; the three versions were equally represented. Compared to the control cases in which no D-dimer was given, knowledge of an abnormal D-dimer resulted in more “likely” clinical scores using the Wells’ score (absolute increase in “likely” of 25-37%, p=0.005, 0.111 and 0.144), while knowledge of a normal D-dimer resulted in more “unlikely” scores (absolute increase in “unlikely” of 27-44%, p=0.001 and 0.070). D-dimer knowledge did not influence the probability assessment when the clinical suspicion was very high. Conclusion: Knowledge of the D-dimer test influences the physician in how the clinical probability for PE is scored. This will have direct clinical consequences, such as unnecessary imaging testing or inappropriate exclusion of the diagnosis. Physicians should therefore make sure that they examine the patient before they take notice of the D-dimer test result. [ABSTRACT FROM AUTHOR]

Abstract: The state of the art of diagnostic evaluation of hemodynamically stable patients with suspected acute pulmonary embolism was reviewed. Diagnostic evaluation should begin with clinical assessment using a validated prediction rule in combination with measurement of D-dimer when appropriate. Imaging should follow only when necessary. Although with 4-slice computed tomography (CT) and 16-slice CT, the sensitivity for detection of pulmonary embolism was increased by combining CT angiography with CT venography, it is not known whether CT venography increases the sensitivity of 64-slice CT angiography. Methods to reduce the radiation exposure of CT venography include imaging only the proximal leg veins (excluding the pelvis) and obtaining discontinuous images. Compression ultrasound can be used instead. In young women, radiation of the breasts produces the greatest risk of radiation-induced cancer. It may be that scintigraphy is the imaging test of choice in such patients, but this pathway should be tested prospectively. A patient-specific approach to the diagnosis of pulmonary embolism can be taken safely in hemodynamically stable patients to increase efficiency and decrease cost and exposure to radiation. [Copyright &y& Elsevier]

Summary: Background: Recombinant activated factor VII (factor VIIa) has prohaemostatic effects in bleeding patients with coagulation abnormalities. We aimed to test the hypothesis that recombinant factor VIIa could reduce perioperative blood loss in patients with normal coagulation systems. Therefore, we assessed safety and efficacy of this drug in patients undergoing retropubic prostatectomy, which is often associated with major blood loss and need for transfusion. Methods: In a double-blind, randomised placebo-controlled trial, we recorded blood loss and transfusion requirements in 36 patients undergoing retropubic prostatectomy, who were randomised to receive an intravenous bolus of recombinant factor VIIa (20 mg/kg or 40 mg/kg) or placebo in the early operative phase. Findings: Median perioperative blood loss was 1235 mL (IQR 1025-1407) and 1089 mL (928-1320) in groups given recombinant factor VIIa 20 mg/kg and 40 mg/kg, respectively, compared with 2688 mL (1707-3565) in the placebo group (p=0.001). Seven of twelve placebo-treated patients were transfused, whereas no patients who received 40 mg/kg recombinant factor VIIa needed transfusion. The odds ratio for receiving any blood product in patients treated with recombinant factor VIIa compared with control patients was 0 (95% CI 0.00-0.33) No adverse events arose. Interpretation: An injection of recombinant factor VIIa can reduce perioperative blood loss and eliminate the need for transfusion in patients undergoing major surgery. [ABSTRACT FROM AUTHOR]

Summary Background: Vitamin K antagonist treatment is effective for prevention and treatment of thromboembolic events but frequent laboratory control and dose-adjustment are essential. Small portable devices have enabled patient self-monitoring of anticoagulation and self-adjustment of the dose. We compared this self-management of oral anticoagulant therapy with conventional management by a specialist anticoagulation clinic in a randomised cross-over study.Methods: 50 patients on long-term oral anticoagulant treatment were included in a randomised controlled crossover study. Patients were self-managed or were managed by the anticoagulation clinic for a period of 3 months. After this period the alternative strategy was followed for each patient. Prothrombin time (expressed as international normalised ratio [INR]) were measured at intervals of 1-2 weeks in both periods without knowledge of type of management. The primary endpoint was the number of measurements within the therapeutic range (therapeutic target value + or - 50.5 INR units).Findings: There was no significant difference in the overall quality of control of anticoagulation between the two study periods. Patients were for 55% and for 49% of the treatment period within a range of 50.5 from the therapeutic target INR during self-management and anticoagulation clinic management, respectively (p=0.06). The proportion of patients who spent most time in the therapeutic target range was larger during self-management than during anticoagulation clinic-guided management. The odds ratio for a better control of anticoagulation (defined as the period of time in the therapeutic target range) during self-management compared with anticoagulation clinic-guided management was 4.6 (95% CI 2.1-10.2). A patient-satisfaction assessment showed superiority of self-management over conventional care.Interpretation: Self-management of INR in the population in this study is feasible and appears to result in control of anticoagulati... [ABSTRACT FROM AUTHOR]

SummaryBackgroundWe have reported previously that, compared with use of second-generation oral contraceptives, the use of third-generation oral contraceptives is associated with increased resistance to the anticoagulant action of activated protein C (APC). Owing to the cross-sectional design of that study, these observations may have been subject to unknown bias or uncontrolled effects of the menstrual cycle. We aimed to overcome these sources of bias by doing a cycle-controlled randomised cross-over trial.MethodsThe response to APC in plasma was assessed in 33 women who received two consecutive cycles of a second-generation oral contraceptive (150 [mu]g levonorgestrel and 30 [mu]g ethinyloestradiol) or a third-generation oral contraceptive (150 [mu]g desogestrel and 30 [mu]g ethinyloestradiol), and who switched preparations after two pill-free cycles. Normalised APC sensitivity ratios were calculated by measurement of the effect of APC on thrombin generation in the plasma of these women and in pooled plasma from 90 controls.FindingsOf the 33 women, five were excluded because not all required plasma samples were available. In the remaining 28 women, the normalised APC sensitivity ratio increased during treatment with both preparations. Compared with levonorgestrel, desogestrel-containing oral-contraceptive treatment caused a highly significant (p<0.0001) additional increase in normalised APC sensitivity ratio (0.51 [95% CI 0.37-0.66]). Normalised APC sensitivity ratios during oral-contraceptive treatment correlated with the values before oral-contraceptive use.InterpretationOral-contraceptive treatment diminishes the efficacy with which APC down-regulates in-vitro thrombin formation. This phenomenon, designated as acquired APC resistance, is more pronounced in women using desogestrel-containing oral contraceptives than in women using levonorgestrel-containing preparations. Whether acquired APC resistance induced by oral contraceptives explains the increased risk... [ABSTRACT FROM AUTHOR]

SummaryBackground Excessive bleeding may complicate cardiac surgery, and is associated with increased morbidity and mortality. Pharmacological strategies to decrease perioperative bleeding have been investigated in a large number of controlled trials, most of which have shown a decrease in blood loss. However, most studies lacked sufficient power to detect a beneficial effect on clinically more relevant outcomes. We did a meta-analysis of all randomised, controlled trials of the three most frequently used pharmacological strategies to decrease perioperative blood loss (aprotinin, lysine analogues [aminocaproic acid and tranexamic acid], and desmopressin).Methods Studies were included if they reported at least one clinically relevant outcome (mortality, rethoracotomy, proportion of patients receiving a transfusion, or perioperative myocardial infarction) in addition to perioperative blood loss. In addition, a separate meta-analysis was done for studies concerning complicated cardiac surgery.Findings We identified 72 trials (8409 patients) that met the inclusion criteria. Treatment with aprotinin decreased mortality almost two-fold (odds ratio 0.55 [95% CI 0.34-0.90]) compared with placebo. Treatment with aprotinin and with lysine analogues decreased the frequency of surgical re-exploration (0.37 [0.25-0.55], and 0.44 [0.22-0.90], respectively). These two treatments also significantly decreased the proportion of patients receiving any allogeneic blood transfusion. By contrast, the use of desmopressin resulted in a small decrease in perioperative blood loss, but was not associated with a beneficial effect on other clinical outcomes. Aprotinin and lysine analogues did not increase the risk of perioperative myocardial infarction; however, desmopressin was associated with a 2.4-fold increase in the risk of this complication. Studies in patients undergoing complicated cardiac surgery showed similar results.Interpretation Pharmacological strategies that decrease perioper... [ABSTRACT FROM AUTHOR]

Objective: To quantitatively assess the efficacy and safety of published randomized trials comparing subcutaneous heparin with continuous intravenous heparin for the initial treatment of deep vein thrombosis.Data Identification: Studies published between January 1986 and April 1991 were identified through computer searches of the MEDLINE database and through reviews of the Science Citation Index, Current Contents, proceedings and abstract books, and references cited in the identified articles. Complete manuscripts were obtained from the authors if only abstracts were available.Study Selection: Eight clinical trials were identified that compared subcutaneous with intravenous heparin administration in patients with venographically confirmed deep vein thrombosis.Data Extraction: Each study was independently analyzed for the percentage distribution of thrombosis, the method of outcome measurement, and the heparin dose. The methodologic strength of each study was assessed using predefined standards for the proper evaluation of a therapeutic intervention with particular emphasis on the type of patient allocation and objective measurements.Results Of Data Analysis: The overall relative risk for efficacy (defined as prevention of extension and recurrence of venous thromboembolism) of subcutaneous compared with intravenous heparin treatment was 0.62 (95% CI, 0.39 to 0.98), whereas for safety (defined as major hemorrhage) it was 0.79 (CI, 0.42 to 1.48).Conclusions: The results of our meta-analysis indicated that heparin administered subcutaneously twice daily in the initial treatment of deep vein thrombosis is more effective and at least as safe as continuous intravenous heparin administration. Administration of heparin subcutaneously may simplify patient treatment and could facilitate home treatment. [ABSTRACT FROM AUTHOR]

Abstract: Background: The implementation of evidence from clinical studies into daily clinical practice is not a straightforward process. We developed a standardized questionnaire to explore clinical practice patterns in the management of VTE, in particular about the use of pre-clinical probability and D-dimer testing and on the home treatment of pulmonary embolism (PE). Methods: The standardized questionnaire was sent to all 394 physician members of the Italian Society of Thrombosis and Haemostasis (SISET) by e-mail. The questionnaire contained three groups of questions: about general information, about the diagnostic process for both deep venous thrombosis (DVT) and PE, and about home-therapy of PE. Results: One hundred and twenty-eight (32.5%) physicians responded the questionnaire. For DVT diagnosis 69 (54.3%) physicians answered that they always use the D-dimer test; 4 (3.1%) do never use it; whereas only 11 (8.7%) take notice of the D-dimer result before visiting the patients; 38 (29.9%) use only clinical judgment to assess pre-clinical probability of disease. For the diagnosis of PE 80 (66.1%) physicians always use the D-dimer test, whereas 3 (2.5%) do never use it; whereas 14 (11.7%) take notice of the D-dimer result before visiting the patients; 50 (41.3%) use only clinical judgment to assess pre-clinical probability. Sixty-six (59.5%) clinicians declared to treat patients with PE at home, when feasible. Conclusion: The diagnostic approach to VTE among expert physicians appears to be heterogeneous; in particular there is no widespread use of clinical prediction rules. The majority of expert physicians appear to consider the possibility of treating at home patients with PE. [Copyright &y& Elsevier]