Summary Background Placenta-mediated pregnancy complications include pre-eclampsia, late pregnancy loss, placental abruption, and birth of a small-for-gestational-age (SGA) neonate. These ...complications are leading causes of maternal, fetal, and neonatal morbidity and mortality in high-income countries. Affected women are at high risk of recurrence in subsequent pregnancies; however, effective strategies to prevent recurrence are absent. Findings from our previous study-level meta-analysis suggested that low-molecular-weight heparin reduced the risk of recurrent placenta-mediated pregnancy complications. However, we identified significant heterogeneity in the results, possibly due to trial design or inclusion criteria. To identify which patients benefit from, and which outcomes are prevented by, low-molecular-weight heparin, we did an individual patient data meta-analysis. Methods We did a systematic review in May, 2013, which identified eight eligible randomised trials done between 2000 and 2013 of low-molecular-weight heparin to prevent recurrent placenta-mediated pregnancy complications. We excluded studies on the basis of the wrong population, the study being ongoing, inability to confirm eligibility of participants, intervention stopped too early, and no response from the principal investigator. We requested individual patient data from the study authors for eligible women (women pregnant at the time of the study with a history of previous pregnancy that had been complicated by one or more of the following: pre-eclampsia, placental abruption, birth of an SGA neonate <10th percentile, pregnancy loss after 16 weeks' gestation, or two losses after 12 weeks' gestation) and recoded, combined, and analysed the data for our meta-analysis. The primary outcome was a composite of early-onset (<34 weeks) or severe pre-eclampsia, birth of an SGA neonate (<5th percentile), late pregnancy loss (≥20 weeks' gestation), or placental abruption leading to delivery, assessed on an intention-to-treat basis. We assessed risk of bias with the Cochrane Risk of Bias tool. This study is registered with PROSPERO, number CRD42013006249. Findings We analysed data from 963 eligible women in eight trials: 480 randomly assigned to low-molecular-weight heparin and 483 randomly assigned to no low-molecular-weight heparin. Overall, the risk of bias was not substantial enough to affect decisions regarding trial inclusion. Participants were mostly white (795/905; 88%) with a mean age of 30·9 years (SD 5·0) and 403/963 (42%) had thrombophilia. In the primary analysis, low-molecular-weight heparin did not significantly reduce the risk of recurrent placenta-mediated pregnancy complications (low-molecular-weight heparin 62/444 14% versus no low-molecular-weight heparin 95/443 (22%) absolute difference −8%, 95% CI −17·3 to 1·4, p=0·09; relative risk 0·64, 95% CI 0·36–1·11, p=0·11). We noted significant heterogeneity between single-centre and multicentre trials. In subgroup analyses, low-molecular-weight heparin in multicentre trials reduced the primary outcome in women with previous abruption (p=0·006) but not in any of the other subgroups of previous complications. Interpretation Low-molecular-weight heparin does not seem to reduce the risk of recurrent placenta-mediated pregnancy complications in at-risk women. However, some decreases in event rates might have been too small for the power of our study to explore. Funding Canadian Institutes of Health Research.
Thromboses of abdominal veins outside the iliac–caval axis are rare but clinically relevant. Early deaths after splanchnic vein thrombosis occur in 5–30% of cases. Sequelae can be liver failure or ...bowel infarction after splanchnic vein thrombosis, renal insufficiency after renal vein thrombosis, ovarian infarction after ovarian vein thrombosis. Local cancer or infections are rare in Budd–Chiari syndrome, and common for other sites. Inherited thrombophilia is detected in 30–50% of patients. Myeloproliferative neoplasms are the main cause of splanchnic vein thrombosis: 20–50% of patients have an overt myeloproliferative neoplasm and/or carry the molecular marker JAK2 V617F. Renal vein thrombosis is closely related to nephrotic syndrome; finally, ovarian vein thrombosis can complicate puerperium. Heparin is used for acute treatment, sometimes in conjunction with systemic or local thrombolysis. Vitamin K-antagonists are recommended for 3–6 months, and long-term in patients with Budd-Chiari syndrome, unprovoked splanchnic vein thrombosis, or renal vein thrombosis with a permanent prothrombotic state such as nephrotic syndrome.
Patients with venous thromboembolism (VTE) should receive a decision on the duration of anticoagulant treatment (AT) that is often not easy to make. Sixteen Italian clinical centers included patients ...with recent VTE in the START2-POST-VTE register and reported the decisions taken on duration of AT in each patient and the reasons for them. At the moment of this report, 472 (66.9%) of the 705 patients included in the registry were told to stop AT in 59.3% and to extend it in 40.7% of patients. Anticoagulant treatment lasted ≥3 months in >90% of patients and was extended in patients with proximal deep vein thrombosis because considered at high risk of recurrence or had thrombophilic abnormalities. d-dimer testing, assessment of residual thrombus, and patient preference were also indicated among the criteria influencing the decision. In conclusion, Italian doctors stuck to the minimum 3 months AT after VTE, while the secondary or unprovoked nature of the event was not seen as the prevalent factor influencing AT duration which instead was the result of a complex and multifactorial evaluation of each patient.
Venous thrombosis typically involves the lower extremities. Rarely, it can occur in cerebral, splanchnic, or renal veins, with a frightening clinical impact. Other rare manifestations are ...upper-extremity deep vein thrombosis, that can complicate with pulmonary embolism and post-thrombotic syndrome, and retinal vein occlusion, significantly affecting the quality of life. This review is focused on venous thromboses at unusual extra-abdominal sites. Local infections or cancer are frequent in cerebral sinus-venous thrombosis. Upper-extremity deep vein thrombosis is mostly due to catheters or effort-related factors. Common risk factors are inherited thrombophilia and oral contraceptive use. Acute treatment is based on heparin; in cerebral sinus-venous thrombosis, local or systemic fibrinolysis should be considered in case of clinical deterioration. Vitamin-K antagonists are recommended for 3–6 months; indefinite anticoagulation is suggested for recurrent thrombosis or unprovoked thrombosis and permanent risk factors. However, such recommendations mainly derive from observational studies; there are no data about long-term treatment of retinal vein occlusion.
Little information is available about the clinical history of patients with incidentally detected splanchnic vein thrombosis and its therapeutic management remains controversial. The aim of this ...study was to assess the risk factors, therapeutic strategies, and long-term outcomes of incidentally detected splanchnic vein thrombosis.
We analysed data from patients with incidentally detected splanchnic vein thrombosis who were enrolled in an international, multicentre, prospective cohort study of splanchnic vein thrombosis between 2008 and 2012. The study was done at 31 centres in 11 countries (Italy, South Korea, Germany, Canada, Belgium, the Netherlands, Brazil, USA, France, Israel, UK). Information about demographic characteristics, risk factors, and treatment was collected. The study outcomes during the 2-year follow-up were major bleeding (International Society on Thrombosis and Haemostasis definition plus the need for hospital admission), thrombotic events (venous or arterial thromboses), and mortality. The primary analysis period was from the diagnosis of incidentally detected splanchnic vein thrombosis until the first adjudicated clinical outcome or the end of follow-up.
Between May 2, 2008, and Jan 30, 2012, we enrolled 177 patients with incidentally detected splanchnic vein thrombosis (median age 57 years IQR 49-66, 118 67% men, 138 78% patients with portal vein thrombosis). The most common underlying diseases were liver cirrhosis (82 46% patients) and solid cancer (62 35% patients). Anticoagulant treatment was prescribed to 109 (62%) patients. Median duration of anticoagulation was 6 months (IQR 5-12) for patients who received parenteral anticoagulants alone and 24 months (IQR 12-24) for patients treated with vitamin K antagonists. During a median follow-up of 2 years (IQR 1-2), the incidence of major bleeding was 3·3 events (95% CI 1·7-6·3) per 100 patient-years and the incidence of thrombotic events was 8·0 events (95% CI 5·2-12·1) per 100 patient-years. On-treatment incidence was 3·2 events (95% CI 1·2-8·4) per 100 patient-years for major bleeding and 3·9 events (95% CI 1·6-9·5) per 100 patient-years for thrombotic events. In multivariate analysis, anticoagulant treatment as a time-dependent variable reduced the incidence of thrombotic events (hazard ratio 0·85, 95% CI 0·76-0·96) without increasing the risk of major bleeding (p>0·05). In patients with clinically suspected splanchnic vein thrombosis, the incidence of major bleeding was 3·9 events (95% CI 2·6-5·7) per 100 patient-years and the incidence of thrombotic events was 7·0 events (95% CI 5·2-9·3) per 100 patient-years.
Our results show that the prognosis of incidentally detected splanchnic vein thrombosis is similar to that of clinically suspected splanchnic vein thrombosis and suggest that similar treatment strategies should be applied.
Pfizer Canada research grant.
Hypercoagulable states and triggering factors (surgery, trauma, immobilization, pregnancy, and use of oral contraceptives) are associated with an increased risk for deep venous thrombosis of the ...lower extremities. In contrast, risk factors for deep venous thrombosis of the upper extremities have not been identified.
To evaluate the prevalence of hypercoagulable states and triggering factors in patients with primary deep venous thrombosis of the upper extremities.
Frequency-matched case-control study.
Hemophilia and thrombosis center at a university hospital.
36 patients who had primary deep venous thrombosis of the upper extremities, 121 patients who had primary deep venous thrombosis of the lower extremities, and 108 healthy controls. Patients who had deep venous thrombosis of the lower extremities and study controls were frequency-matched by age, sex, geographic origin, and social status with patients who had deep venous thrombosis of the upper extremities.
Resistance to activated protein C was evaluated by a clotting method based on the activated partial thromboplastin time. If test results were abnormal or borderline, DNA analysis for substitution in coagulation factor V gene was done. Antithrombin, protein C, protein S, antiphospholipid antibodies, and total plasma homocysteine levels were also measured.
Prevalences of abnormalities of the natural anticoagulant system (9%) and hyperhomocysteinemia (6%) in patients who had deep venous thrombosis of the upper extremities were similar to prevalences of both factors in controls (6% and 7%, respectively) but lower than in patients who had deep venous thrombosis of the lower extremities (31% and 14%, respectively). Antiphospholipid antibodies were found only in patients who had venous thrombosis of the lower extremities (7%). The overall prevalence of hypercoagulable states in patients who had thrombosis of the upper extremities (15%) was similar to that in controls (12%) but was significantly lower than that in patients who had thrombosis of the lower extremities (56%). A recent history of strenuous exercise of muscles in the affected extremity was the most frequent triggering factor for patients who had deep venous thrombosis in the upper extremities (33%).
This preliminary study indicates that the prevalence of hypercoagulable states is low in patients who have primary deep venous thrombosis of the upper extremities.
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