Incidence and prognosis of superficial vein thrombosis during pregnancy and the post-partum period: a Danish nationwide cohort study

BACKGROUND

The incidence of superficial vein thrombosis (SVT) of the legs and the subsequent risk of venous thromboembolism during pregnancy and the post-partum period is unknown. To better understand the clinical course of SVT during these times, we aimed to estimate the incidence rate of SVT during pregnancy and in the post-partum period, as well as the risk of subsequent venous thromboembolism.

METHODS

In this nationwide cohort study, we collected data on all pregnant women who delivered between Jan 1, 1997, and Dec 31, 2017, in Denmark were extracted from the Danish Medical Birth Register, the Danish National Patient Registry, and the Danish National Prescription Registry. Data on ethnicity were not available. Incidence rates per 1000 person-years were calculated for each trimester and the antepartum and post-partum period. Among women with a pregnancy-related SVT, risk of subsequent venous thromboembolism within the same pregnancy or post-partum period were calculated and compared with a matched cohort of pregnant women without SVT using Cox proportional hazards analysis.

FINDINGS

During 1 276 046 deliveries, 710 diagnoses of lower extremity SVT occurred from conception up to 12 weeks postpartum (0·6 per 1000 person-years [95% CI 0·5-0·6]). The incidence rates of SVT per 1000 person-years were 0·1 (95% CI 0·1-0·2) during the during the first trimester, 0·2 (0·2-0·3) during the second trimester, and 0·5 (0·5-0·6) during the third trimester. The incidence rate was 1·6 per 1000 person-years (95% CI 1·4-1·7) during the post-partum period. Of the 211 women with antepartum SVT included in the analysis, 22 (10·4%) were diagnosed with venous thromboembolism, compared with 25 (0·1%) in women without SVT (hazard ratio 83·3 [95% CI 46·3-149·7]).

INTERPRETATION

The incidence rate of SVT during pregnancy and the post-partum period was low. However, if SVT during pregnancy was diagnosed, the risk of developing venous thromboembolism during the same pregnancy was high. These results might help physicians and patients to make decisions about anticoagulant management of pregnancy-related SVT.

FUNDING

None.

Risk of venous thromboembolism and bleeding after major surgery for ovarian cancer: standard in-hospital versus extended duration of thromboprophylaxis

BACKGROUND

Venous thromboembolism (VTE) is a frequent complication in patients with ovarian cancer after major surgery. Based on limited data, international guidelines recommend extended thromboprophylaxis for up to 28 days.

OBJECTIVES

To assess the incidence of VTE and bleeding within 30 days following major surgery in patients with ovarian cancer and to evaluate the association between VTE and thromboprophylaxis duration.

METHODS

This was a single-center, retrospective, "before-after" cohort study in patients with ovarian cancer undergoing major surgery. Before July 2019, the local protocol mandated a standard course of thromboprophylaxis during hospital stay only. From July 2019 onward, patients received extended thromboprophylaxis for 28 days. The cumulative incidences of VTE and major bleeding within 30 days after surgery were estimated using the Kaplan-Meier method, with 95% confidence intervals (CIs). Cox regression analysis was performed to evaluate the association between thromboprophylaxis duration and VTE incidence.

RESULTS

Between January 2018 and December 2020, 250 women were included, of which 118 (47.2%) received extended and 132 (52.8%) standard thromboprophylaxis. During follow-up, 12 patients developed VTE (cumulative incidence, 4.8%; 95% CI, 2.1-7.4) and 2 major bleeding (cumulative incidence 0.8%; 95% CI, 0.0-1.9). Compared with standard thromboprophylaxis, VTE incidence was numerically lower with extended duration of thromboprophylaxis (5/118 [4.2%] vs 7/132 [5.3%]) but not significantly different (hazard ratio, 0.80; 95% CI, 0.25-2.52). The risk of major bleeding was similar in both groups (1/118 [0.8%] vs 1/132 [0.8%]; hazard ratio, 1.12; 95% CI, 0.07-17.89).

CONCLUSIONS

The cumulative VTE incidence in patients with ovarian cancer following major surgery was considerable. Extended thromboprophylaxis was safe and associated with a numerically lower risk of VTE but not significantly different.

Onset of labor and use of analgesia in women using thromboprophylaxis with 2 doses of low-molecular-weight heparin: insights from the Highlow study

BACKGROUND

Peripartum management of women using low-molecular-weight heparin (LMWH) varies widely. Minimum time intervals are required between LMWH injection and neuraxial procedure, and they differ by dose.

OBJECTIVES

The objective of this study was to describe the onset of labor and use of analgesia in women using LMWH and to compare practices between intermediate-dose and low-dose LMWH.

METHODS

In the Highlow study (NCT01828697), 1110 women were randomized to intermediate-dose or low-dose LMWH and were instructed to discontinue LMWH when labor commenced unplanned or 24 hours prior to planned delivery. The required time interval since last injection to receive a neuraxial procedure was ≥24 hours for intermediate-dose LMWH or ≥12 hours for low-dose LMWH.

RESULTS

In total, 1018 women had an ongoing pregnancy for ≥24 weeks. Onset of labor was spontaneous in 198 of 509 (39%) women on intermediate-dose LMWH and in 246 of 509 (49%) on low-dose LMWH. With unplanned onset, a neuraxial procedure was performed in 37% on intermediate-dose and in 48% on low-dose LMWH (risk difference -11%, 95% CI -20% to -2%). Based on time interval, 61% on intermediate-dose and 82% on low-dose LMWH were eligible for a neuraxial procedure. With planned onset, 68% on intermediate-dose and 66% on low-dose LMWH received a neuraxial procedure, whereas 81% and 93%, respectively, were eligible for a neuraxial procedure (risk difference -13%, 95% CI -18% to -8%).

CONCLUSION

With spontaneous onset of labor, neuraxial procedures were performed less often in women using intermediate-dose LMWH. Irrespective of onset, fewer women on intermediate-dose LMWH than those on low-dose LMWH were eligible for neuraxial procedures based on required time intervals since the last LMWH injection.

Intermediate-dose versus low-dose low-molecular-weight heparin in pregnant and post-partum women with a history of venous thromboembolism (Highlow study): an open-label, multicentre, randomised, controlled trial

BACKGROUND

Pregnancy-related venous thromboembolism is a leading cause of maternal morbidity and mortality, and thromboprophylaxis is indicated in pregnant and post-partum women with a history of venous thromboembolism. The optimal dose of low-molecular-weight heparin to prevent recurrent venous thromboembolism in pregnancy and the post-partum period is uncertain.

METHODS

In this open-label, randomised, controlled trial (Highlow), pregnant women with a history of venous thromboembolism were recruited from 70 hospitals in nine countries (the Netherlands, France, Ireland, Belgium, Norway, Denmark, Canada, the USA, and Russia). Women were eligible if they were aged 18 years or older with a history of objectively confirmed venous thromboembolism, and with a gestational age of 14 weeks or less. Eligible women were randomly assigned (1:1), before 14 weeks of gestational age, using a web-based system and permuted block randomisation (block size of six), stratified by centre, to either weight-adjusted intermediate-dose or fixed low-dose low-molecular-weight heparin subcutaneously once daily until 6 weeks post partum. The primary efficacy outcome was objectively confirmed venous thromboembolism (ie, deep-vein thrombosis, pulmonary embolism, or unusual site venous thrombosis), as determined by an independent central adjudication committee, in the intention-to-treat (ITT) population (ie, all women randomly assigned to treatment). The primary safety outcome was major bleeding which included antepartum, early post-partum (within 24 h after delivery), and late post-partum major bleeding (24 h or longer after delivery until 6 weeks post partum), assessed in all women who received at least one dose of assigned treatment and had a known end of treatment date. This study is registered with ClinicalTrials.gov, NCT01828697, and is now complete.

FINDINGS

Between April 24, 2013, and Oct 31, 2020, 1339 pregnant women were screened for eligibility, of whom 1110 were randomly assigned to weight-adjusted intermediate-dose (n=555) or fixed low-dose (n=555) low-molecular-weight heparin (ITT population). Venous thromboembolism occurred in 11 (2%) of 555 women in the weight-adjusted intermediate-dose group and in 16 (3%) of 555 in the fixed low-dose group (relative risk [RR] 0·69 [95% CI 0·32-1·47]; p=0·33). Venous thromboembolism occurred antepartum in five (1%) women in the intermediate-dose group and in five (1%) women in the low-dose group, and post partum in six (1%) women and 11 (2%) women. On-treatment major bleeding in the safety population (N=1045) occurred in 23 (4%) of 520 women in the intermediate-dose group and in 20 (4%) of 525 in the low-dose group (RR 1·16 [95% CI 0·65-2·09]).

INTERPRETATION

In women with a history of venous thromboembolism, weight-adjusted intermediate-dose low-molecular-weight heparin during the combined antepartum and post-partum periods was not associated with a lower risk of recurrence than fixed low-dose low-molecular-weight heparin. These results indicate that low-dose low-molecular-weight heparin for thromboprophylaxis during pregnancy is the appropriate dose for the prevention of pregnancy-related recurrent venous thromboembolism.

FUNDING

French Ministry of Health, Health Research Board Ireland, GSK/Aspen, and Pfizer.

Risk of recurrence in women with venous thromboembolism related to estrogen-containing contraceptives: Systematic review and meta-analysis

BACKGROUND

The risk of recurrence after a venous thromboembolism (VTE) related to estrogen-containing contraceptives is a key driver to guide anticoagulant treatment decisions.

OBJECTIVE

To estimate the incidence rate of recurrent VTE after discontinuation of anticoagulant treatment in women with a first episode of VTE related to estrogen-containing contraceptives.

METHODS

Embase, MEDLINE, and the CENTRAL were searched from 1 January 2008 to 27 May 2021 for prospective and retrospective studies reporting on recurrence after a first VTE related to estrogen-containing contraceptives. Risk of bias was assessed using QUIPS tool. Recurrence rates per 100 patient-years were pooled using Knapp-Hartung random-effects meta-analysis. Incidence rates were reported separately based on study follow-up duration (≤1 year, 1-5 years, and >5 years) and for several subgroups.

RESULTS

A total of 4,120 studies were identified, of which 14 were included. The pooled recurrence rate was 1.57 (95%-CI: 1.10-2.23; I2  = 82%) per 100 patient-years. Recurrence rates per 100 patient-years were 2.73 (95%-CI: 0.00-3643; I2  = 80%) for studies with ≤1 year follow-up, 1.35 (95%-CI: 0.68-2.68; I2  = 44%) for studies with 1-5 years follow-up, and 1.42 (95%-CI: 0.84-2.42; I2  = 78%) for studies with >5 years follow-up.

CONCLUSION

Among women with VTE associated with estrogen-containing contraceptives, the risk of recurrence after stopping anticoagulation is low, which favors short-term anticoagulation. Large prospective studies on VTE recurrence rates and risk factors after stopping short-term anticoagulants are needed.

Sex-specific differences in clot resolution 3 weeks after acute pulmonary embolism managed with anticoagulants-A substudy of the EINSTEIN-PE study

BACKGROUND

It is unknown whether differences in clot structure and resolution contribute to the reported risk differences of recurrent venous thromboembolism (VTE) between men and women.

PATIENTS/METHODS

We used data from the EINSTEIN-PE study, a randomized, multicenter, non-inferiority study in which patients 18 years and older with acute symptomatic pulmonary embolism (PE) were randomized to rivaroxaban or enoxaparin followed by a vitamin K antagonist. PE was diagnosed by computed tomography pulmonary angiography scan or high-probability ventilation/perfusion scintigraphy. Three weeks after randomization a follow-up scan was performed. An independent adjudication committee assessed the degree of vascular obstruction.

RESULTS AND CONCLUSIONS

A total of 371 participants including 174 (46.9%) women and 197 (53.0%) men were included in the present analysis. At 3 weeks, there was no difference between men and women in complete clot resolution: 39.6% and 40.2%, respectively. The absolute reduction in pulmonary vascular obstruction at week 3 was also similar: 12.9% (95% confidence interval [CI]: 11.6-14.2) in men and 12.1% (95% CI: 10.4-13.7) in women, corresponding to a resolution ratio of 0.29 (95% CI: 0.24-0.33) and 0.35 (95% CI: 0.28-0.42), respectively. No differences in clot resolution were observed between men and women diagnosed with acute PE at 3 weeks after start of anticoagulant therapy. These findings suggest that the reported higher rate of VTE recurrence in men cannot be explained by decreased clot resolution.

Contemporary best practice in the management of pulmonary embolism during pregnancy

Approximately 1–2 per 1000 pregnancies are complicated by venous thromboembolism (VTE). VTE includes deep vein thrombosis (DVT) and pulmonary embolism (PE) and the diagnostic management of pregnancy-related VTE is challenging. Current guidelines vary greatly in their approach to diagnosing PE in pregnancy as they base their recommendations on scarce and weak evidence. The pregnancy-adapted YEARS diagnostic algorithm is well tolerated and is the most efficient diagnostic algorithm for pregnant women with suspected PE, with 39% of women not requiring computed tomographic pulmonary angiography. Low-molecular-weight heparin is the first-choice anticoagulant treatment in pregnancy and should be continued until 6 weeks postpartum and for a minimum of 3 months. Direct oral anticoagulants should be avoided in women who want to breastfeed. Management of delivery needs a multidisciplinary approach in order to decide on an optimal delivery plan. Neuraxial analgesia can be given in most patients, provided time windows since last low-molecular-weight heparin dose are respected. Women with a history of VTE are at risk of recurrence during pregnancy and in the postpartum period. Therefore, in most women with a history of VTE, thromboprophylaxis in subsequent pregnancies is indicated.

The reviews of this paper are available via the supplemental material section.

Heavy menstrual bleeding on direct factor Xa inhibitors: Rationale and design of the MEDEA study

BACKGROUND

In premenopausal women, treatment with direct oral factor Xa inhibitors is associated with an increased risk of heavy menstrual bleeding (HMB) compared with vitamin K antagonists (VKA). Treatment with the direct oral thrombin inhibitor dabigatran appears to be associated with a reduced risk of HMB compared with VKA. These findings come from small observational studies or post hoc analyses of trials in which HMB was not a primary outcome. Use of tranexamic acid during the menstrual period may be effective in patients with HMB, but prospective data regarding efficacy and safety in patients on anticoagulant treatment are lacking.

RATIONALE AND DESIGN

A direct comparison of a factor Xa inhibitor and a thrombin inhibitor with HMB as primary outcome, as well as an evaluation of the effects of adding tranexamic acid in women with anticoagulant-associated HMB is highly relevant for clinical practice. The MEDEA study is a randomized, open-label, pragmatic clinical trial to evaluate management strategies in premenopausal women with HMB associated with factor Xa inhibitor therapy.

OUTCOMES

Women using factor Xa inhibitors with proven HMB, as assessed by a pictorial blood loss assessment chart (PBAC) score of >150, will be randomized to one of three study arms: (i) switch to dabigatran; (ii) continue factor Xa inhibitor with addition of tranexamic acid during the menstrual period; or (iii) continue factor Xa inhibitor without intervention. The primary outcome is the difference in PBAC score before and after randomization. Here, we present the rationale and highlight several unique features in the design of the study.

Bacterial co-infection of the respiratory tract in ventilated children with bronchiolitis; a retrospective cohort study

Background

Viral bronchiolitis is the most common cause of respiratory failure requiring invasive ventilation in young children. Bacterial co-infections may complicate and prolong paediatric intensive care unit (PICU) stay. Data on prevalence, type of pathogens and its association with disease severity are limited though. These data are especially important as bacterial co-infections may be treated using antibiotics and could reduce disease severity and duration of PICU stay. We investigated prevalence of bacterial co-infection and its association with disease severity and PICU stay.

Methods

Retrospective cohort study of the prevalence and type of bacterial co-infections in ventilated children performed in a 14-bed tertiary care PICU in The Netherlands. Children less than 2 years of age admitted between December 2006 and November 2014 with a diagnosis of bronchiolitis and requiring invasive mechanical ventilation were included. Tracheal aspirates (TA) and broncho-alveolar lavages (BAL) were cultured and scored based on the quantity of bacteria colony forming units (CFU) as: co-infection (TA > 10^{^5}/BAL > 10^{^4} CFU), low bacterial growth (TA < 10^{^5}/BAL < 10^{^4} CFU), or negative (no growth). Duration of mechanical ventilation and PICU stay were collected using medical records and compared against the presence of co-infection using univariate and multivariate analysis.

Results

Of 167 included children 63 (37.7%) had a bacterial co-infection and 67 (40.1%) low bacterial growth. Co-infections occurred within 48 h from intubation in 52 out 63 (82.5%) co-infections. H.influenza (40.0%), S.pneumoniae (27.1%), M.catarrhalis (22.4%), and S.aureus (7.1%) were the most common pathogens. PICU stay and mechanical ventilation lasted longer in children with co-infections than children with negative cultures (9.1 vs 7.7 days, p = 0.04 and 8.1vs 6.5 days, p = 0.02).

Conclusions

In this large study, bacterial co-infections occurred in more than a third of children requiring invasive ventilation for bronchiolitis and were associated with longer PICU stay and mechanical ventilation. These findings support a clinical trial of antibiotics to test whether antibiotics can reduce duration of PICU stay.