Effective management of acute deep vein thrombosis: direct oral anticoagulants.

Deep vein thrombosis (DVT) is a manifestation of venous thromboembolism (VTE) and accounts for most venous thromboembolic events. Although DVT is not directly life-threatening, thrombi in the proximal veins of the leg can embolize to the lungs to form a pulmonary embolism, which may prove rapidly fatal. If untreated, DVT can also lead to significant morbidity, including development of post-thrombotic syndrome. Among many risk factors, surgery, hospitalization, older age and active cancer increase the risk of VTE, and a previous event increases the risk of recurrence. Early detection and effective clot resolution are vital in managing DVT. Conventional approaches to acute treatment of VTE involve initial fast-acting parenteral heparin overlapping with and followed by vitamin K antagonist therapy. However, vitamin K antagonists have a narrow therapeutic window, require regular monitoring, and have multiple food and drug interactions. Results from phase III clinical studies involving direct Factor Xa and IIa inhibitors suggest that these agents provide an alternative therapeutic option that overcomes some of the complications associated with conventional treatment with predictable pharmacological properties and convenient dosing schedules. Analysis of data from the rivaroxaban EINSTEIN studies also suggests that these agents have the potential to improve patient-reported treatment satisfaction and reduce the length of hospital stay compared with conventional therapy. This review considers these treatment options, suitable treatment durations to prevent recurrence, and the management of DVT treatment in challenging patient groups.

The value of routine screening for peripheral arterial disease in stable outpatients with a history of coronary artery or cerebrovascular disease.

BACKGROUND: Frequently unrecognised, PAD is associated with reduced quality of life and an increased mortality rate because of a greater propensity for fatal ischaemic events. PAD commonly coexists with coronary and cerebrovascular disease and is associated with poorer outcomes in such patients. The Edinburgh Claudication Questionnaire (ECQ) and the ankle-brachial index (ABI) are screening methods to identify the presence of PAD. This study used these methods to estimate the rate of previously undiagnosed PAD and to validate the ECQ against ABI in a Canadian outpatient population with manifest cerebrovascular or coronary disease. METHODS: At a regular office visit, patients completed the ECQ and were categorised as ECQ(+) or ECQ(-). All ECQ(+) and a randomly selected 25% of ECQ(-) patients were referred for ABI measurement. An ABI < 0.9 was considered positive. The prevalence of PAD in the patient population and the sensitivity and specificity of the ECQ score against the ABI were assessed. RESULTS: Of 2235 patients enrolled, 815 were selected for an ABI [ECQ(-), n = 478; ECQ(+), n = 337]. Extrapolated PAD prevalence in the total population was 12.3% (highest arterial pressure [HAP] method) and 20.8% (lowest arterial pressure [LAP] method), with a significantly higher prevalence found in diabetic patients than non-diabetic patients (p < 0.0001). Because ECQ is only a measure of symptomatic disease, it had poor sensitivity (35.3% and 25.8%), but high specificity (88.2% and 88.3%) using the HAP and LAP methods of ABI measurement, respectively. CONCLUSIONS: Undiagnosed PAD is common in stable outpatients with a prior history of manifest cardiovascular disease, particularly in those with diabetes. The ECQ does not possess the diagnostic value of the ABI in detecting PAD in this high-risk population, but may be useful to raise suspicion of PAD to be confirmed by ABI assessment.

Economic burden and cost determinants of deep vein thrombosis during 2 years following diagnosis: a prospective evaluation.

BACKGROUND: Few studies have evaluated the long-term economic consequences of deep vein thrombosis (DVT). None of them have incorporated prospectively collected clinical data to ensure accurate identification of incident cases of DVT and DVT-related health outcomes of interest, such as post-thrombotic syndrome (PTS). OBJECTIVES: To prospectively quantify medical and non-medical resource use and costs related to DVT during 2 years following diagnosis, and to identify clinical determinants of costs. METHODS: Three hundred and fifty-five consecutive patients with acute DVT were recruited at seven Canadian hospital centers. Resource use and cost information were retrieved from three sources: weekly patient-completed cost diaries, nurse-completed case report forms, and the Quebec provincial administrative healthcare database (RAMQ). RESULTS: The rate of DVT-related hospitalization was 3.5 per 100 patient-years (95% confidence interval [CI] 2.2-4.9). Patients reported a mean (standard deviation) of 15.0 (14.5) physician visits and 0.7 (1.2) other healthcare professional visits. The average cost of DVT was $5180 (95% CI $4344-6017) in Canadian dollars, with 51.6% of costs being attributable to non-medical resource use. Multivariate analysis identified four independent predictors of costs: concomitant pulmonary embolism (relative increase in cost [RIC] 3.16; 95% CI 2.18-4.58), unprovoked DVT (RIC 1.65; 95% CI 1.28-2.13), development of PTS during follow-up (RIC 1.35; 95% CI 1.05-1.74), and management of DVT in the inpatient setting (RIC 1.79; 95% CI 1.33-2.40). CONCLUSIONS: The economic burden of DVT is substantial. The use of measures to prevent the occurrence of PTS and favoring outpatient care of DVT has the potential to diminish costs.

Relation between D-dimer level, venous valvular reflux and the development of post-thrombotic syndrome after deep vein thrombosis.

BACKGROUND: The pathophysiology of post-thrombotic syndrome (PTS) is postulated to involve persistent venous obstruction and venous valvular reflux. OBJECTIVE: To study the association between D-dimer level, valvular reflux and the PTS in a well-defined cohort of deep vein thrombosis (DVT) patients. METHODS: Consecutive patients with acute symptomatic DVT were recruited at eight centers and were followed for 24months. D-dimer was measured at 4months. A standardized ultrasound assessment for popliteal valvular reflux was performed at 12months. Using the Villalta scale, patients were assessed for PTS during follow-up by evaluators who were unaware of D-dimer or reflux results. RESULTS: Three hundred and eighty-seven patients were recruited; of these, 305 provided blood samples for D-dimer and 233 had a 12-month reflux assessment. PTS developed in 45.1% of subjects. Mean D-dimer was significantly higher in patients with vs. without PTS (712.0 vs. 444.0µgL(-1) ; P=0.02). In logistic regression analyses adjusted for warfarin use at the time of D-dimer determination and risk factors for PTS, D-dimer level significantly predicted PTS (P=0.03); when stratifying for warfarin use at the time of blood draw, adjusted odds ratio (OR) for developing PTS per unit difference in log D-dimer was 2.33 (95% CI 0.89, 6.10) in those not on warfarin vs. 1.25 (95% CI 0.87, 1.79) in those on warfarin. Ipsilateral reflux was more frequent in patients with moderate-to-severe PTS than in patients with mild PTS (65% vs. 40%, respectively; P=0.01) and was independently associated with moderate-to-severe PTS in logistic regression analyses (P=0.01). CONCLUSION: D-dimer levels, measured 4months after DVT in patients not on warfarin, are associated with subsequent development of PTS. Venous valvular reflux is associated with moderate-to-severe PTS.

Determinants of health-related quality of life during the 2 years following deep vein thrombosis.

BACKGROUND/OBJECTIVES: We prospectively measured change in quality of life (QOL) during the 2 years after a diagnosis of deep vein thrombosis (DVT) and evaluated determinants of QOL, including development of the post-thrombotic syndrome (PTS). PATIENTS/METHODS: Consecutive patients with acute DVT were recruited from 2001 to 2004 at eight hospitals in Canada. At study visits at baseline, and 1, 4, 8, 12 and 24 months, clinical data were collected, standardized PTS assessments were performed, and QOL questionnaires were self-completed. Generic QOL was measured using the Short-Form Health Survey-36 (SF-36) questionnaire. Venous disease-specific QOL was measured using the Venous Insufficiency Epidemiological and Economic Study (VEINES)-QOL/Sym questionnaire. The change in QOL scores over a 2-year follow-up was assessed. The influence of PTS and other characteristics on QOL at 2 years was evaluated using multivariable regression analyses. RESULTS: Among the 387 patients recruited, the average age was 56 years, two-thirds were outpatients, and 60% had proximal DVT. The cumulative incidence of PTS was 47%. On average, QOL scores improved during follow-up. However, patients who developed PTS had lower scores at all visits and significantly less improvement in QOL over time (P-values for PTS*time interaction were 0.001, 0.012, 0.014 and 0.006 for PCS, MCS, VEINES-QOL and VEINES-Sym). Multivariable regression analyses showed that PTS (P < 0.0001), age (P = 0.0009), proximal DVT (P = 0.01) and inpatient status (P = 0.04) independently predicted 2-year SF-36 PCS scores. PTS alone independently predicted 2-year VEINES-QOL (P < 0.0001) and VEINES-Sym (P < 0.0001) scores. CONCLUSIONS: Development of PTS is the principal determinant of health-related QOL 2 years after DVT. Our study provides prognostic information on patient-reported outcomes after DVT and emphasizes the need for effective prevention and treatment of the PTS.

Functional consequences of neuropeptide FF receptors stimulation in mouse: a cerebral glucose uptake study.

The brain substrates involved in the pharmacological effects of neuropeptide FF (NPFF, Phe-Leu-Phe-Gln-Pro-Gln-Arg-Phe-NH2) including interactions with opioid systems, were investigated with the [14C]-2-deoxyglucose ([14C]-2-DG) autoradiography technique in mouse. The changes in cerebral activity were mapped after i.p. administration of 1DMe ([D-Tyr1,(NMe)Phe3]NPFF; 70 mg/kg), a neuropeptide FF analogue partially resistant to peptidases, alone or in combination with morphine (15 mg/kg). 1DMe induced a rapid decrease in the cerebral activity in the thalamus, the pontine reticular nuclei and the cerebellar cortex, brain regions involved in the control of motor activity and/or the processing of sensory data. This decrease, observed when 1DMe was administered 5 min before [14C]-2-DG, was reversed by morphine, which was devoid of significant effect at this time. When administered 30 min before the radioisotope, 1DMe was without effect, whereas morphine induced a significant increase in cerebral glucose utilization in the caudate putamen, the primary somatosensory cortex, the thalamus, the superior colliculus, the pontine reticular nuclei and the spinal cord. The association of morphine and 1DMe significantly increased cerebral glucose utilization in the same regions as morphine alone and also in three additional regions: the auditory cortex, the inferior colliculus and the dorsomedial periaqueductal gray. Following systemic administration, 1DMe and morphine modulated cerebral activity in brain regions involved in pain transmission and motor control, but their effects were temporally shifted, as were their effects on horizontal locomotor activity. However, neuropeptide FF-induced changes in brain activity were modulated in part by opioid receptors activation.

Lack of concordance between plasma markers of cardiovascular risk and intima-media thickness in patients with type 2 diabetes.

AIM: Endothelial dysfunction, oxidative stress and systemic inflammation play an important role in the enhanced cardiovascular risk in diabetes. Carotid intima-media thickness (IMT), a widely accepted marker of subclinical atherosclerosis, is known to be increased in patients with type 2 diabetes. The relationships between plasma markers of cardiac risk and carotid IMT are not well known. We therefore studied a group of patients with type 2 diabetes to evaluate the relationships between plasma markers of cardiac risk and carotid IMT. DESIGN AND PATIENTS: We measured carotid IMT and the levels of soluble endothelial adhesion molecules [sE-selectin, intercellular cell adhesion molecule-1 (sICAM-1) and vascular cell adhesion molecule-1 (sVCAM-1)], C-reactive protein (CRP) and 8-isoprostane in 40 patients with type 2 diabetes without clinical macrovascular complications (HbA1c<10%, duration of diabetes<12 years) and 25 healthy subjects. We then examined the correlations between these plasma markers, carotid IMT and various clinical and biochemical parameters. RESULTS: Diabetic patients had higher plasma sE-selectin (p=0.03), sICAM-1 (p=0.05), CRP (p=0.047) and 8-isoprostane (p=0.001) concentrations than control subjects. Mean IMT values were identical (0.63 +/- 0.02 mm) in diabetic (range, 0.40-0.92 mm) and healthy subjects (range, 0.45-0.85 mm). In diabetic patients, stepwise multivariate analysis showed that HbA1c and plasma glucose were independent predictors of sE-selectin (r2=0.19 and r2=0.17, p<0.01, respectively), whereas waist circumference and body mass index (BMI) were predictors of sICAM-1 (r2=0.27, p=0.001 and r2=0.22, p=0.002, respectively). Waist circumference was the only predictor of CRP (r2=0.2, p<0.01), and systolic blood pressure was the only predictor of 8-isoprostane (r2=0.19, p=0.006). In control subjects, similar analysis showed that plasma glucose and waist circumference were predictors of sE-selectin and sICAM-1, respectively (r2=0.2, p<0.05). CONCLUSIONS: These results indicate that some well-controlled type 2 diabetic patients free of clinical macrovascular complications have elevated plasma markers of cardiovascular risk without having increased IMT. The elevation of plasma markers of endothelial cell activation (sE-selectin and s-ICAM-1) or inflammation (CRP) and oxidative stress (8-isoprostane) in diabetics vs. controls is distinct from and cannot be explained simply by differences in the burden of atherosclerosis as assessed by carotid IMT.

Identification of neuropeptide FF-related peptides in rodent spinal cord.

Peptides which should be generated from the neuropeptide FF (NPFF) precursor were identified in mouse and rat spinal cord, by using reverse phase high pressure liquid chromatography with radioimmunoassay and electrospray mass spectrometry detection. In both species, two octapeptides, NPFF (Phe-Leu-Phe-Gln-Pro-Gln-Arg-Phe-amide) and NPSF (Ser-Leu-Ala-Ala-Pro-Gln-Arg-Phe-amide) were identified but a longer peptide NPA-NPFF (Asn-Pro-Ala-Phe-Leu-Phe-Gln-Pro-Gln-Arg-Phe-amide) was present at the highest concentration in rat spinal cord. In mouse, the homologous peptide, SPA-NPFF (Ser-Pro-Ala-Phe-Leu-Phe-Gln-Pro-Gln-Arg-Phe-amide) was not detected. Both peptides NPFF and NPSF reverse morphine-induced analgesia in the tail flick test. Our data reveal species differences in the maturation of NPFF precursor.

Enzymatic degradation of neuropeptide FF and SQA-neuropeptide FF in the mouse brain.

Degradation of neuropeptide FF (NPFF) and SQA-neuropeptide FF (SQA-NPFF) by mouse brain sections was investigated by using capillary electrophoresis with UV detection for the separation and the identification of the degradation products. The half disappearance time of SQA-NPFF was 2-fold greater than that of NPFF. NPFF was cleaved preferentially into an inactive metabolite, Gln-Arg-Phe-NH2, in the cerebrum slices. SQA-NPFF was hydrolyzed by an unidentified degrading activity to generate NPFF, and NPFF accounted for a larger part of SQA-NPFF degradation in the hindbrain and cervical spinal cord than in the cerebrum slices. These findings suggest that, depending on the brain regions, NPFF produced from SQA-NPFF could prolong the biologic effects of SQA-NPFF.

Anti-opioid efficacy of neuropeptide FF in morphine-tolerant mice.

The modulatory effects of 1DMe (d-Tyr-Leu-(NMe)Phe-Gln-Pro-Gln-Arg-Phe-NH2), an agonist of Neuropeptide FF (NPFF) receptors, on opioid antinociceptive activity have been compared in naive and tolerant mice in the tail-flick and the hot-plate tests. In naive mice, 1DMe alone had no effect on pain threshold but decreased dose-dependently (3-22 nmol) the analgesic activity of morphine in both tests. In tolerant mice, injections of 60-fold lower doses of 1DMe (0.05-0.5 nmol) reverse morphine-induced analgesia in the tail-flick test but this anti-opioid effect was no longer observed with the highest doses of 1DMe tested (3-22 nmol). In the hot-plate test, the anti-opioid action of 1DMe was not detected, whatever doses tested. Neither the NPFF-like immunoreactivity content of spinal cord and of olfactory bulbs, nor the density of NPFF receptors in olfactory bulbs, were altered. These results indicate that a chronic morphine treatment modifies the pharmacological properties of NPFF but the type of pain test is crucial in determining NPFF effects.

Neutrophil-associated inflammatory responses in rats are inhibited by phenylarsine oxide.

NADPH oxidase is a phagocyte-specific enzyme which produces O2- and so initiates a cascade of reactive oxygen species formation. Inflammatory diseases involve overproduction of reactive oxygen species which induce tissue damage. Phenylarsine oxide has been described previously as a complete and direct inhibitor of NADPH oxidase in vitro that acts by covalently binding to vicinal thiol groups of a membrane-associated component of the enzyme. In the present work, the potential anti-inflammatory effect of phenylarsine oxide was tested on two experimental models in rats, carrageenan-induced paw oedema and lipopolysaccharide-mediated lung inflammation. Intraperitoneal injection of phenylarsine oxide reduced (i) reactive oxygen species production by rat phagocytes, (ii) neutrophil infiltration into the lung after inhalation of lipopolysaccharide and (iii) neutrophil-dependent oedema induced by carrageenan in hindpaws. We conclude that phenylarsine oxide has anti-inflammatory properties which are probably exerted by its ability to inhibit neutrophil NADPH oxidase-dependent reactive oxygen species production. The present work provides the basis for the development of new anti-inflammatory, arsenic-free agents reacting at the phenylarsine oxide site, which seems to be the Achilles' heel of NADPH oxidase.

Anticentromere autoantibodies. Evaluation of an ELISA using recombinant fusion protein CENP-B as antigen.

OBJECTIVE: To evaluate an enzyme-linked immunosorbent assay (ELISA) for anticentromere autoantibodies (ACA). METHODS: Sera from 611 patients with scleroderma, CREST (calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, telangiectasias), Raynaud's disease, and connective tissue disease control patients were studied by ELISA using the fusion protein CENP-B, by immunofluorescence on dividing HEp-2 cells, and by immunoblotting on chromosomes and CENP-B. RESULTS: Compared with immunofluorescence, the CENP-B ELISA sensitivity was 94% and the specificity was 93%. In 19.7% of the cases, there was a probability of a false-positive result and in 1.9%, a probability of a false-negative result, yielding positive and negative predictive values of 0.80 and 0.98, respectively. CONCLUSION: The CENP-B ELISA is a sensitive and specific assay for ACA.

Coupling of microdialysis with capillary electrophoresis: a new approach to the study of drug transfer between two compartments of the body in freely moving rats.

The feasibility of in vivo microdialysis and capillary electrophoresis for pharmacokinetic studies was tested. Microdialysis probes were inserted in the jugular vein and brain of rats. After an intraperitoneal injection of phenobarbital, microdialysis was performed in the brain and the blood simultaneously in each rat under freely moving conditions. Capillary electrophoresis with ultraviolet absorption was used to measure phenobarbital in blood and brain dialysates. The time course of phenobarbital in the blood and in the extracellular space of the brain was followed. The results demonstrated that microdialysis can be used for pharmacokinetic studies in freely moving animals. Capillary electrophoresis has the potential to improve the time resolution of microdialysis. Other advantages of microdialysis and capillary electrophoresis for pharmacokinetic studies are discussed.

Evaluation of the severity of systemic sclerosis by nailfold capillary microscopy in 112 patients.

The authors used nailfold capillary microscopy (NCM) to evaluate 112 patients with systemic sclerosis spectrum disorders (SSc). Patients were classified as S1 if they had skin involvement proximal to the metacarpo-phalangeal joints. S2 if they had at least two minor SSc American Rheumatism Association criteria, and S3 if they had at least two CREST criteria (calcinosis, Raynaud's, esophageal motility disorder, sclerodactyly, telangiectases), without S1 or S2 criteria. Disease duration from the first symptom was similar in all groups (7.17 +/- 8.98 years). Disease severity was determined by a total score of seven target organ involvements. S1 patients had a greater degree of skin and pulmonary involvement, with a mean score of 26.2 +/- 17.3. S2 patients had a mean score of 13.8 +/- 12.4, and had mostly vascular and digestive involvement, in comparison with S3 patients (7.2 +/- 7.2; p less than 0.001 and p less than 0.01 respectively). NCM sensitivity for S1 and S2 was 93.6%. NCM correlated with the degree of target organ involvement (p less than 0.01). Three NCM profiles established were: "mild," normal or borderline capillaries; "moderate," other abnormalities with no capillary telangiectases; and "severe," abnormalities other than those of the mild profile, with capillary telangiectases.

Prognostic significance of anticentromere antibodies and anti-topoisomerase I antibodies in Raynaud's disease. A prospective study.

Seventy-seven patients with Raynaud's disease were studied for a mean of 4 years (range 1-11 years) to determine the relationship between autoantibodies and long-term clinical outcome. Anticentromere antibodies (ACA) were assayed by indirect immunofluorescence and by immunoblotting of HeLa cell chromosome extracts. Antibodies to topoisomerase I (anti-topo I) were assayed by immunodiffusion and immunoblotting. Antibodies to the major centromeric protein, CENP-B, and anti-topo I were studied by enzyme-linked immunosorbent assay (ELISA). Eight patients developed telangiectasias, 4 developed skin tightening, and 4 developed a connective tissue disease other than scleroderma. The presence of ACA at the start of the study was associated with the development of telangiectasias (P less than 0.003). An initial 100-kd band on immunoblot in conjunction with a positive anti-topo I ELISA result was associated with the development of tight skin (P less than 0.0025), while a 100-kd band with a negative anti-topo I ELISA result was associated with the subsequent development of a connective tissue disease other than scleroderma (P less than 0.0073). Patients who were initially ACA positive, had the 100-kd band on immunoblot, or had positive ELISA results for anti-topo I or for anti-CENP-B were 63-fold more likely to develop signs of connective tissue disease by the end of the study (P less than 0.000009). The presence of any of these autoantibodies was more sensitive (100%), although less specific (75%), than were findings from nailfold capillaroscopy (sensitivity 67% and specificity 95%) in predicting subsequent clinical progression. We conclude that findings of assays for anti-topo I and ACA complement the findings from nailfold capillaroscopy in providing useful prognostic information in Raynaud's disease.

Anticytoskeletal autoantibody to microfilament anchorage sites recognizes novel focal contact proteins.

Actin microfilaments are anchored to the plasma membrane at focal contacts. Using an indirect immunofluorescence method, we detected an autoantibody reactive with focal contacts in PtK2, HEp-2, and BHK-21 cells in serum from two patients with early systemic sclerosis. With double immunofluorescence, using the actin-binding drug phalloidin, we localized the plaques decorated by these sera specifically at the termini of microfilament bundles. The reactive antigens were identified by immunoblotting as proteins of 80,000- and 75,300-mol wt in PtK2, and of 53,500-mol wt in HEp-2 and BHK-21 cells. The 53,500-mol wt protein was also identified in rat skeletal, myocardial, and smooth muscle tissues. The detergent solubility of these proteins suggested that they may be linked to the plasma membrane. The autoantigens were immunologically distinct from vinculin and alpha-actinin, two major proteins also known to be concentrated at the ends of microfilament bundles. Our observations suggest that this novel anticytoskeletal autoantibody may identify a novel family of vertebrate cell proteins involved in the linkage of microfilaments to the plasma membrane at focal contacts.

Doppler ultrasonic investigation of Raynaud's phenomenon: effect of temperature on blood velocity.

We have used spectral analysis of signals from a pulsed, range-gated Doppler ultrasonic instrument to make quantitative measurements of arterial blood flow velocity in the hands of normal subjects and persons with Raynaud's phenomenon. We measured the peak velocity during the cardiac cycle and the time integral of the velocity signal over the cardiac cycle. This latter parameter gives a sensitive indication of the degree of vasoconstriction in response to cold. Our preliminary results, based on findings in 13 subjects, suggest that Doppler ultrasound can differentiate persons with Raynaud's phenomenon from normal subjects.