Anticoagulation for venous thromboembolism.
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Biomedical subjects
Publications and source records attributed to M Moia.
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An association between deficiency of tissue factor pathway inhibitor (TFPI) and thrombosis has not been clearly demonstrated in humans, but previous studies have focused on the measurement of plasma TFPI, which is only a small part of the total body TFPI. The major fraction of this natural anticoagulant can be measured in plasma after release by heparin injection. To investigate if deficiency of heparin-releasable TFPI is associated with thrombosis. we measured TFPI activity in plasma before and 10 min after intravenous injection of 7500 IU unfractionated heparin in 64 young patients with venous thrombosis, 49 young patients with arterial thrombosis and 38 healthy individuals. Post-heparin TFPI activity levels were significantly lower in the group of patients with venous thrombosis than in controls (mean+/-SD: 230%+/-39 vs 260%+/-34, p = 0.0002), whereas there was no difference for patients with arterial thrombosis. Defining the normal range as the mean+/-2 SD of TFPI activity in controls, twelve patients had low post-heparin TFPI activity levels, seven with venous and five with arterial thrombosis. Low levels of TFPI activity were confirmed by immunoassay in six of the seven patients with venous thrombosis and two of the five patients with arterial thrombosis, and were present also in at least one first degree relative of six patients, suggesting that the defect might be inheritable. However, the causative role of low heparin-releasable TFPI remains uncertain, because co-segregation of the defect with thrombotic symptoms could not be demonstrated in the small number of families studied.
Acquired deficiency of naturally occurring anticoagulant proteins, due to loss in the urine, has been proposed as one of the major thrombogenic alterations in nephrotic proteinuria. The aim of this study was to investigate if proteinuria may induce deficiency of tissue factor pathway inhibitor (TFPI). TFPI, protein C (PC) and antithrombin (AT) were measured in 31 patients with nephrotic proteinuria, compared with 62 age- and sex-matched controls. Plasma levels of TFPI activity, total TFPI antigen and free TFPI antigen were significantly higher in patients with nephrotic proteinuria than in controls, and none of the patients had TFPI deficiency. Intravenous injection of 7500 IU unfractionated heparin induced a significant further increase of TFPI in two patients with high pre-heparin levels. Also plasma levels of PC were significantly higher in patients than in controls. Mean AT antigen levels were not significantly different between patients and controls, and AT activity was only marginally increased with borderline significance. Three out of 31 patients had substantial acquired AT deficiency. In conclusion, proteinuria is not associated with TFPI deficiency, but with a marked increase of this anticoagulant protein. The acquired thrombophilic diathesis of patients with nephrotic proteinuria can therefore not be attributed to TFPI deficiency.
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OBJECTIVE: To investigate the efficacy of using a rapid plasma D-dimer test as an adjunct to compression ultrasound for diagnosing clinically suspected deep vein thrombosis. DESIGN: D-dimer concentrations were determined in all patients with a normal ultrasonogram at presentation. Repeat ultrasonography was performed 1 week later only in patients with abnormal D-dimer test results. MAIN OUTCOME AND MEASURES: Patients with normal ultrasonograms were not treated with anticoagulants and were followed for 3 months for thromboembolic complications. SETTING: University research and affiliated centres. SUBJECTS: 946 patients with clinically suspected deep vein thrombosis. RESULTS: Ultrasonograms were abnormal at presentation in 260 (27.5%) patients. Of the remaining 686 patients tested for D-dimer, 88 (12.8%) had abnormal concentrations. During follow up venous thromboembolic complications occurred in one of the 598 patients who were not treated with anticoagulants and who had an initial normal ultrasonogram and D-dimer concentration, whereas thromboembolic complications occurred in two of the 83 untreated patients who had abnormal D-dimer concentrations but a normal repeat ultrasonogram. The cumulative incidence of venous thromboembolic complications during follow up was 0.4% (95% confidence interval 0% to 0.9%). The rapid plasma D-dimer test used as an adjunct to compression ultrasonography resulted in a reduction in the mean number of repeat ultrasound examinations and additional hospital visits from 0.7 to 0.1 per patient. CONCLUSIONS: Testing for D-dimer as an adjunct to a normal baseline ultrasound examination decreased the number of subsequent ultrasound examinations considerably without any increased risk of venous thromboembolic complications in patients not receiving anticoagulants. The use of ultrasound and testing for D-dimer enabled treatment decisions to be made at the time of presentation in most patients.
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The R506Q mutation ("Factor V Leiden") is responsible for the resistance to activated Protein C (aPCR), that is evaluated by coagulation tests. Such tests cannot be used in patients with lupus anticoagulants (LAs), due to the interfering effect exerted by these antibodies on "in vitro" phospholipid-dependent coagulation tests. For this reason, assays have been developed to evaluate aPCR that are insensitive to the presence of LA antibodies. We evaluated two such coagulation tests in the plasma of 82 consecutive patients with LAs. By polymerase chain reaction 3 patients (3.6%) were found heterozygous for the R506Q mutation. aPCR was evaluated by two clotting assays, proposed to be "insensitive" to the presence of LAs: 1. aPCR-tissue factor-based assay, using Factor V deficient plasma and 1:40 diluted test plasma; 2. aPCR-dRVVT-based assay with highly concentrated phospholipids. Their interassay coefficient of variation was 28% and 6.2%, respectively. Compared to the polymerase chain reaction analysis, the 2 tests displayed the following characteristics: sensitivity 67% vs 100%, specificity 92% vs 96%, positive predictive value 25% vs 50%, negative predictive value 99% vs 100%. respectively. Among LA patients without the R506Q mutation, 5 scored positive in the aPCR-tissue factor-based assay, 2 in the aPCR-dRVVT-based assay and another one in both assays. Our findings suggest that the aPCR-dRVVT-based test is more reliable and sensitive than the aPCR-tissue factor-based one to the R506Q mutation in patients with LAs. Both assays, when negative, make unlikely the presence of the R506Q mutation. Polymerase chain reaction analysis remains, however, to be performed when either test is positive.
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Post-thrombotic syndrome (PTS) in young women may cause impairment in the quality of life of otherwise healthy people. We aimed to evaluate the prevalence of PTS and its risk factors in young women. We evaluated 51 women with at least one previous episode of symptomatic, objectively documented deep vein thrombosis (DVT) before the age of 40. Each patient asked for symptoms had a physical examination, a color-coded Doppler ultrasonography of the superficial and deep venous system and an extensive laboratory evaluation for the congenital and acquired coagulation abnormalities predisposing to thrombosis. The median follow-up was 47 months. PTS was absent in 37%, mild in 55%, moderate in 4% and severe in 4% of patients. No correlation was found between PTS and the presence of coagulation abnormalities, triggering factors, recurrences, use of elastic stockings for one year after DVT, degree of recanalization, presence of superficial reflux. Patients with a body mass index (BMI) >22 had an adjusted ratio of 4.7 (98 CI: 1.0-23.3) of developing the PTS. Though severe and moderate PTS are rare, mild PTS is present in the majority of young women after DVT. A BMI >22 is associated to the risk of developing PTS. Attempt to control weight in women after DVT should be considered and studied to prevent PTS.
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The aim of this multicentre, prospective, randomised, dose-ranging study was to compare the safety and efficacy of subcutaneous recombinant hirudin (HBW 023) against intravenous sodium heparin in acute lower limb deep venous thrombosis (DVT). Patients were randomized to treatment with either HBW 023 or heparin for 5 +/- 1 days. HBW 023 was given according to body-weight in three dose groups. Thromboembolic disease was assessed by phlebography and ventilation/perfusion (V/Q) scanning on Day 1 and Day 5 +/- 1. One hundred and fifty-five patients were enrolled, of these 121 were evaluable for efficacy analysis. Significantly fewer patients on HBW 023 developed new V/Q abnormalities during the treatment period, (p = 0.006). There was no difference between the groups in thrombus extension or regression, major bleeding complications or serious adverse events. There were significantly fewer findings of new V/Q mismatch after treatment with HBW 023, and anticoagulant control was superior in these patients.
BACKGROUND: To assess the incidence of bleeding complications during oral anticoagulant therapy (OAT) in a population of patients representative of daily practice in Italian anticoagulation clinics. METHODS DESIGN: prospective, inception-cohort, multicentre. SETTING: Thirty-four anticoagulation clinics federated in the Italian Federation of Anticoagulation Clinics. PATIENTS: 2745 consecutive patients, included from beginning of their first OAT course. Most patients were aged between 60 and 79 y (57.8%), with 8% being > or = 80 y. Venous thromboembolism was the most frequent indication for OAT (one third of all the patients), followed by non ischemic heart disease which mainly included atrial fibrillation (16.8% of patients). Warfarin (in 63.8% of patients) and acenocoumarol were the only anticoagulant drugs used. The targeted anticoagulation intensity was low (INR < or = 2.8) in 71% of patients and high (INR > 2.8) in the remainder. OUTCOMES: Fatal, major and minor bleeding events. Thrombotic events were also recorded, though not analyzed in the present report. FINDINGS: During the 2011 patient-years (pt-y) of follow-up, 153 bleeding complications (7.6% pt-y) were recorded--5 fatal (all cerebral haemorrhages, 0.25% pt-y), 23 major (1.1% pt-y) and 125 minor (6.2% pt-y). The rate of events did not vary according to sex, coumarin type, size of enrolling centre or targeted therapeutic range; it was higher in older patients (10.5% pt-y in those aged > or = 70 y, relative risk--RR--1.75, p < 0.001), in cases where indication for anti-coagulant treatment was peripheral and/or cerebrovascular disease (12.5% pt-y; RR 1.80, p < 0.01) and during the first 90 days of treatment (11% pt-y, RR 1.75, p < 0.001). One fifth of bleeding events occurred at a very low anticoagulation intensity (INR < 2; the category rate being 7.7% pt-y); the rate was 4.8% pt-y in the 2.0-2.9 INR category, reaching 9.5% pt-y, 40.5% pt-y and 200% pt-y in the 3-4.4, 4.5-6.9 and > or = 7 INR categories respectively (RR for INR levels > 4.5 = 7.91, p < 0.0001). CONCLUSIONS: The overall rate of bleeding events recorded in the present study was much lower than that recorded in other (including recent) observational and experimental studies. The risk of bleeding increased in the following cases: age > 70 y; arterial vascular disease as indication for OAT; first 3 months of treatment; INR values > or = 4.5. OAT has become safer in recent years, particularly if monitored in special anticoagulation clinics. Caution should be exercised when prescribing OAT in elderly patients and the intensity anticoagulation levels should be closely monitored to minimize incidental periods of overanticoagulation.
The paper reports on rate and type of thrombotic events occurring during the observational, prospective, inception-cohort, multicenter ISCOAT study. 2,745 unselected, daily practice patients, consecutively referring to 34 Italian anticoagulation clinics to monitor the oral anticoagulant treatment, were included in the study from beginning of their first anticoagulant course. During a total follow-up of 2,011 patient-years of treatment 70 thrombotic events (3.5 per 100 patient years) were recorded in 67 patients: 20 fatal (1%), 39 major (1.9%) and 11 minor (0.6%). 34/70 events occurred within the first 90 days of treatment (relative risk - at multivariate analysis - of < or =90 days vs. >90 = 20.6, C.I. 12.7-33.5; p <0.0001). The risk was higher in patients aged > or =70 y (1.62, C.I. 1.0-2.61; p <0.05), and when indication for anticoagulant treatment was peripheral/cerebral arterial disease (1.84, C.I. 1.01-3.36; p <0.05). The frequency of thrombotic events was 17.5% when international normalised ratio (INR) levels were < 1.5, decreasing to 2.3% for INRs within the 2-2.99 category (relative risk of INRs <2.0 vs. > or =2 = 1.88, C.I. 1.16-3.07; p <0.05). The recorded rate of thrombotic events was lower than that reported in the few available studies. A greater risk should be expected during the first 90 days of treatment, when anticoagulation levels are <2.0 INR, in patients > 70 years and in those with cerebrovascular/peripheral arterial disease.
BACKGROUND: Bleeding is the most serious complication of the use of oral anticoagulation in the prevention and treatment of thromoboembolic complications. We studied the frequency of bleeding complications in outpatients treated routinely in anticoagulation clinics. METHODS: In a prospective cohort from thirty-four Italian anticoagulation clinics, 2745 consecutive patients were studied from the start of their oral anticoagulation (warfarin in 64%, acenocourmarol in the rest). The target anticoagulation-intensity was low (international normalised ratio [INR] < or = 2.8) in 71% of the patients and high (> 2.8) in the remainder. We recorded demographic details and the main indication for treatment and, every 3-4 months, INR and outcome events. Such events included all complications (bleeding, thrombosis, other), although only bleeding events are reported here, and deaths. We divided bleeding into major and minor categories. FINDINGS: 43% of the patients were women. Nearly three-fifths of the patients were aged 60-79; 8% were over 80. The main indication for treatment was venous thrombolism (33%), followed by non-ischaemic heart disease (17%). Mean follow-up was 267 days. Over 2011 patient-years of follow-up, 153 bleeding complications occurred (7.6 per 100 patient-years). 5 were fatal (all cerebral haemorrhages, 0.25 per 100 patient-years), 23 were major (1.1), and 125 were minor (6.2). The rate of events was similar between sexes, coumarin type, size of enrolling centre, and target INR. The rate was higher in older patients: 10.5 per 100 patient-years in those aged 70 or over, 6.0 in those aged under 70 (relative risk 1.75, 95% Cl 1.29-2.39, p < 0.001). The rate was also higher when the indication was peripheral and/or cerebrovascular disease than venous thromboembolism plus other indications (12.5 vs 6.0 per 100 patient-years) (1.80, 1.2-2.7, p < 0.01), and during the first 90 days of treatment compared with later (11.0 vs 6.3, 1.75, 1.27-2.44, p < 0.001). A fifth of the bleeding events occurred at low anticoagulation intensity (INR < 2, rate 7.7 per 100 patient-years of follow-up). The rates were 4.8, 9.5, 40.5, and 200 at INRs 2.0-2.9, 3-4.4, 4.5-6.9, and over 7, respectively (relative risks for INR > 4.5, 7.91, 5.44-11.5, p < 0.0001). INTERPRETATION: We saw fewer bleeding events than those recorded in other observational and experimental studies. Oral anticoagulation has become safer in recent years, especially if monitored in anticoagulation clinics. Caution is required in elderly patients and anticoagulation intensity should be closely monitored to reduce periods of overdosing.
PURPOSE: To assess the natural history and risk factors for thrombosis in a large cohort of unselected patients with antiphospholipid antibodies. PATIENTS AND METHODS: Three hundred sixty consecutive patients (118 males, 242 females, median age 39 years [range 2 to 78]) fulfilling the currently accepted criteria for diagnosis of lupus anticoagulant (LAC) (n = 326) and/or raised immunoglobulin G anticardiolipin antibodies (IgG ACA) (n = 185) were collected from 16 Italian institutions and prospectively observed for a median of 3.9 years (range 0.5 to 5). Main endpoints were the occurrence of arterial or venous thrombosis, the outcome of pregnancies, and any severe complications leading to hospitalization or death. RESULTS: Thirty-four patients developed a thrombotic complication, with a total incidence of 2.5% patient-years. Multivariate logistic regression analysis identified two independent risk factors for thrombotic events: a previous thrombosis (RR 4.9; 95% CI, 1.76 to 13.7; P < 0.005) and IgG ACA titer above 40 units (RR 3.66; 95% CI, 1.24 to 10.8; P < 0.01). A total of 28 pregnancies were observed in 25 women and 11 (39%) were abortive. Adverse pregnancy outcomes were significantly more frequent in women with a history of miscarriage or vascular occlusion (9/16, 56%) than in asymptomatic women (2/12, 17%) (P = 0.035). Four patients developed non-Hodgkin's lymphoma during the follow-up. Eighteen patients died. Vascular events and hematological malignancies represented the most frequent causes of death (n = 5 for each). CONCLUSIONS: The present study shows that: (a) previous thrombosis and ACA titer > 40 U are independent predictors of thrombosis; (b) history of miscarriage or vascular disease is significantly associated with adverse pregnancy outcome; (c) hematological malignancies can develop during follow-up in patients with antiphospholipid antibodies.
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In this prospective study, we evaluated the predictive value of activated partial thromboplastin time on day 8 post transplantation for event-free survival in patients who had had orthotopic liver transplants; both death and retransplantation within 6 months were the events considered. In a 4-year period, 109 patients had orthotopic liver transplants in our hospital, and 104 were eligible for the study since they survived and were not given new transplants within 8 days. The activated partial thromboplastin time was significantly longer in patients who survived event-free for less than 6 months than in those with longer event-free survivals. Kaplan-Meier curves showed that patients with normal activated partial thromboplastin times were nine times more likely to survive more than 6 months without events than patients with prolonged values. The positive predictive value of activated partial thromboplastin time for event-free survival was 88% and the negative predictive value was 54%, indicating that the test is useful for predicting patient outcome. We suggest that activated partial thromboplastin time be performed on day 8 post transplantation to predict the medium-term event-free survival.