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Lori-Ann Linkins

Publications and source records attributed to Lori-Ann Linkins.

10 recordsLinked to original sources
PubMed2006

An evaluation of D-dimer in the diagnosis of pulmonary embolism: a randomized trial.

BACKGROUND: It may be safe to omit additional diagnostic testing in selected patients with suspected pulmonary embolism (PE) who have a negative D-dimer test, but this approach has never been evaluated in a randomized, controlled trial. OBJECTIVE: To determine if additional diagnostic testing can be safely withheld in patients with suspected PE who have negative erythrocyte agglutination D-dimer test results. DESIGN: Randomized comparisons in 2 subgroups of a prospective multicenter study. SETTING: 7 university hospitals. PATIENTS: 1126 outpatients or inpatients with suspected PE; of these, 456 patients with negative erythrocyte agglutination D-dimer test results were randomly assigned to the intervention groups. Patients were classified into 2 clinical probability groups: those with a low clinical probability of PE (low-probability group) and those with a moderate or high clinical probability of PE, a nondiagnostic ventilation-perfusion lung scan, and no evidence of proximal deep venous thrombosis on bilateral ultrasonography (moderate- or high-probability group). INTERVENTIONS: The experimental intervention for both probability groups was no further diagnostic testing for PE. The control intervention for the low-probability group was a ventilation-perfusion lung scan followed by ultrasonography of the proximal deep veins of the legs on the same day. If the lung scan was nondiagnostic, ultrasonography of the legs was repeated 7 and 14 days later. The control intervention for the moderate- or high-probability group was ultrasonography of the proximal deep veins of the legs after 7 and 14 days. In the control and experimental groups, anticoagulation was withheld or withdrawn if PE was not diagnosed. MEASUREMENTS: Symptomatic venous thromboembolism (VTE) during 6 months of follow-up. RESULTS: Prevalence of VTE was 15.2% in the 1126 enrolled patients. In the low-probability group, VTE occurred during follow-up in 0 of 182 patients who had no additional diagnostic testing and in 1 of 185 patients who had additional testing (difference, -0.5 percentage point [95% CI, -3.0 to 1.6 percentage points]). In the moderate- or high-probability group, VTE occurred during follow-up in 1 of 41 patients who had no additional diagnostic testing and in 0 of 41 patients who had additional testing (difference, 2.4 percentage points [CI, -6.4 to 12.6 percentage points]). LIMITATIONS: The authors could not enroll 2000 patients as originally planned; 3 randomly assigned patients did not receive the allocated intervention, and 7 received inadequate follow-up. Personnel who performed follow-up evaluations were not blinded to the results of diagnostic testing at enrollment or to allocation group assignments. CONCLUSION: In patients with a low probability of PE who have negative D-dimer results, additional diagnostic testing can be withheld without increasing the frequency of VTE during follow-up. Low clinical probability and negative D-dimer results occur in 50% of outpatients and in 20% of inpatients with suspected PE.

Fibrin Fibrinogen Degradation Products↗
PubMed2005

Interobserver agreement on ultrasound measurements of residual vein diameter, thrombus echogenicity and Doppler venous flow in patients with previous venous thrombosis.

INTRODUCTION: In patients with new symptoms in a leg previously affected by deep vein thrombosis (DVT), the presence of thrombus on ultrasound cannot be assumed to be due to recurrent thrombosis. Several parameters have been suggested to differentiate between acute and chronic thrombus on ultrasound, including measurement of residual vein diameter during compression, thrombus echogenicity and Doppler assessment of venous flow, but studies on the reproducibility of these measurements are sparse. OBJECTIVE: To determine interobserver agreement on measurement of residual vein diameter, thrombus echogenicity and Doppler venous flow in patients with residual thrombus in the veins of the lower limb. MATERIALS AND METHODS: Patients with previous proximal DVT who had a high likelihood of residual thrombosis, but without symptoms of recurrent DVT, had ultrasound examinations independently performed by two examiners on the same day. Interobserver agreement on measurement of residual vein diameter, thrombus echogenicity and Doppler venous flow was evaluated. RESULTS: We determined that interobserver agreement on these measurements was moderate. The mean difference between paired measurements of residual vein diameter was 2.2 mm (95th centile, 8.0 mm). When both examiners agreed residual thrombus was present, 54% of the variance of the measurement of residual vein diameter was accounted for by the paired measurements. The weighted kappa coefficient for thrombus echogenicity was 0.01 and for Doppler venous flow was 0.51. CONCLUSIONS: The error associated with ultrasound measurements of residual vein diameter, thrombus echogenicity and flow appears to be considerable.

Adult↗
PubMed2005

New anticoagulant therapy.

The development of new anticoagulants is expanding the list of drugs that can be used to prevent and treat venous and arterial thrombosis. New parenteral anticoagulants have been developed to overcome the limitations of heparin and low-molecular-weight heparin, whereas novel orally active anticoagulants have been designed to provide more streamlined therapy than vitamin K antagonists. This review identifies the molecular targets of new anticoagulants, describes the results of clinical trials, and provides clinical perspective on the opportunities for new anticoagulants.

Administration, Oral↗
PubMed2005

Pharmacology and clinical potential of direct thrombin inhibitors.

Direct thrombin inhibitors represent a new class of anticoagulants that bind directly to thrombin and block the enzyme's interactions with its substrates. These agents have been developed, at least in part, to overcome the limitations of heparin and vitamin K antagonists. This paper (a) reviews why thrombin is an ideal target for new anticoagulants, (b) describes the pharmacological profiles of the various direct thrombin inhibitors, (c) outlines the potential mechanistic advantages of parenteral direct thrombin inhibitors over heparin, (d) defines the potential benefits of ximelagatran, the first orally active direct thrombin inhibitor, over vitamin K antagonists, and (e) provides clinical perspective on the strengths and weaknesses of the various parenteral and oral direct thrombin inhibitors.

Animals↗
PubMed2004

Change in thrombus length on venous ultrasound and recurrent deep vein thrombosis.

BACKGROUND: Despite successful treatment, deep vein thrombosis may not fully resolve in some patients. Consequently, in patients with new symptoms in a previously affected leg, noncompressibility on ultrasound cannot be assumed to be due to recurrent thrombosis; therefore, we sought to determine interobserver agreement on ultrasound measurements of thrombus length and identify the change in length that is likely to indicate thrombus extension. METHODS: Cross-sectional study of patients with previous proximal deep vein thrombosis and residual ultrasound abnormalities, but without symptoms suggestive of recurrence. The patients had a standardized series of measurements of thrombus length independently performed by 2 ultrasonographers. The outcome measure was the agreement between the ultrasonographers on the distance of thrombus margins from 4 anatomical landmarks. RESULTS: There was good interobserver agreement on thrombus length when measured from the saphenofemoral junction, mid-popliteal fossa, and mid-patella (93% or more of the variance was accounted for by the paired measurements). Using these landmarks, the 95th percentile for the absolute difference between paired measurements was 8.9 cm for the saphenofemoral junction, 8.5 cm for the mid-popliteal fossa, and 8.4 cm for the mid-patella. CONCLUSIONS: When 2 ultrasound examinations are compared, an apparent increase in thrombus length of 9 cm or greater is likely to be supportive of a diagnosis of recurrent deep vein thrombosis. Increases in thrombus length of less than 9 cm appear to be within the bounds of measurement error.

Adult↗
PubMed2003

Clinical impact of bleeding in patients taking oral anticoagulant therapy for venous thromboembolism: a meta-analysis.

BACKGROUND: Clinicians should consider the clinical impact of anticoagulant-related bleeding when deciding on the duration of anticoagulant therapy in patients with venous thromboembolism. PURPOSE: To provide reliable estimates of the clinical impact of anticoagulant-related bleeding, defined as the case-fatality rate of major bleeding and the risk for intracranial bleeding. DATA SOURCES: MEDLINE (January 1989 to May 2003), Cochrane Controlled Trial Registry, thromboembolism experts, and reference lists; English-language literature only. STUDY SELECTION: Randomized, controlled trials and prospective cohort studies that investigated patients with venous thromboembolism who received oral anticoagulant therapy (target international normalized ratio, 2.0 to 3.0) for at least 3 months and that reported major bleeding and death as primary study outcomes. DATA EXTRACTION: Two reviewers independently extracted data on the number of anticoagulant-related major and intracranial bleeding episodes and on whether these events were fatal or nonfatal. DATA SYNTHESIS: The authors analyzed 33 studies involving 4374 patient-years of oral anticoagulant therapy. For all patients, the case-fatality rate of major bleeding was 13.4% (95% CI, 9.4% to 17.4%) and the rate of intracranial bleeding was 1.15 per 100 patient-years (CI, 1.14 to 1.16 per 100 patient-years). For patients who received anticoagulant therapy for more than 3 months, the case-fatality rate of major bleeding was 9.1% (CI, 2.5% to 21.7%), and the rate of intracranial bleeding was 0.65 per 100 patient-years (CI, 0.63 to 0.68 per 100 patient-years) after the initial 3 months of anticoagulation. CONCLUSION: The clinical impact of anticoagulant-related major bleeding in patients with venous thromboembolism is considerable, and clinicians should take this into account when deciding whether to continue long-term oral anticoagulant therapy in an individual patient.

Administration, Oral↗
PubMed2003

Reduction of out-of-hospital symptomatic venous thromboembolism by extended thromboprophylaxis with low-molecular-weight heparin following elective hip arthroplasty: a systematic review.

BACKGROUND: Numerous trials and meta-analyses have shown that extended out-of-hospital prophylaxis with low-molecular-weight heparin reduces asymptomatic and symptomatic venous thromboembolism after total hip arthroplasty. We hypothesized that knowledge of the results of screening tests may have resulted in overdiagnosis of symptomatic venous thromboembolism in many of these studies. The purpose of this analysis was to obtain an accurate estimate of the absolute risk reduction (ARR) of symptomatic venous thromboembolism after discharge from hospital in controlled studies that avoided this potential bias for overdiagnosis. METHODS: Articles were identified using MEDLINE, EMBASE, and the Cochrane Library databases (January 1980-April 2002). Studies were eligible if the assessment of symptomatic venous thromboembolism was standardized and performed independently of mandatory objective testing. RESULTS: Two studies (907 patients) were eligible for assessment of symptomatic venous thromboembolism, 5 studies (1917 patients) for symptomatic pulmonary embolism, and 7 studies (2425 patients) for fatal pulmonary embolism. In controls vs extended treatment groups, after hospital discharge, the frequency of symptomatic venous thromboembolism was 2.7% vs 1.1% (ARR, 1.56%; 95% confidence interval [CI], -0.21% to 3.3%; number needed to treat, 64); symptomatic pulmonary embolism was 0.36% vs 0% (ARR, 0.36%; 95% CI, -0.3% to 1.36%; number needed to treat, 278); and fatal pulmonary embolism was 0.09% vs 0% (ARR, 0.09%; 95% CI, -0.08% to 0.27%; number needed to treat, 1093). CONCLUSIONS: The absolute reduction in symptomatic venous thromboembolism attributed to extended prophylaxis in some studies and meta-analyses seems to have been overestimated.

Arthroplasty, Replacement, Hip↗
PubMed2003

New anticoagulants.

The limitations of heparin and warfarin have prompted the search for new anticoagulants for the prevention and treatment of venous and arterial thromboembolism. Although many such agents are in development, only a few have reached phase II or higher levels of clinical testing. This article reviews venous and arterial thrombogenesis, discusses the regulation of coagulation, identifies the molecular targets for new anticoagulants currently under development, describes the agents in more advanced stages of clinical testing, and provides clinical perspective on the opportunities for new anticoagulant drugs.

Anticoagulants↗
PubMed2003

An update on new anticoagulants.

A variety of new anticoagulants for the prevention and treatment of venous and arterial thromboembolism are under development. Designed to overcome the limitations of heparin and vitamin K antagonists, these new agents are at various stages of clinical testing. This paper reviews venous and arterial thrombogenesis, discusses the regulation of coagulation, identifies the molecular targets for new anticoagulants, describes new anticoagulants in more advanced stages of clinical testing, and provides perspective on how these agents will impact on practice.

Anticoagulants↗