Aspirin for preventing the recurrence of venous thromboembolism

BACKGROUND

About 20% of patients with unprovoked venous thromboembolism have a recurrence within 2 years after the withdrawal of oral anticoagulant therapy. Extending anticoagulation prevents recurrences but is associated with increased bleeding. The benefit of aspirin for the prevention of recurrent venous thromboembolism is unknown.

METHODS

In this multicenter, investigator-initiated, double-blind study, patients with first-ever unprovoked venous thromboembolism who had completed 6 to 18 months of oral anticoagulant treatment were randomly assigned to aspirin, 100 mg daily, or placebo for 2 years, with the option of extending the study treatment. The primary efficacy outcome was recurrence of venous thromboembolism, and major bleeding was the primary safety outcome.

RESULTS

Venous thromboembolism recurred in 28 of the 205 patients who received aspirin and in 43 of the 197 patients who received placebo (6.6% vs. 11.2% per year; hazard ratio, 0.58; 95% confidence interval [CI], 0.36 to 0.93) (median study period, 24.6 months). During a median treatment period of 23.9 months, 23 patients taking aspirin and 39 taking placebo had a recurrence (5.9% vs. 11.0% per year; hazard ratio, 0.55; 95% CI, 0.33 to 0.92). One patient in each treatment group had a major bleeding episode. Adverse events were similar in the two groups.

CONCLUSIONS

Aspirin reduced the risk of recurrence when given to patients with unprovoked venous thromboembolism who had discontinued anticoagulant treatment, with no apparent increase in the risk of major bleeding. (Funded by the University of Perugia and others; WARFASA ClinicalTrials.gov number, NCT00222677.).

Serial 2-point ultrasonography plus D-dimer vs whole-leg color-coded Doppler ultrasonography for diagnosing suspected symptomatic deep vein thrombosis: a randomized controlled trial

CONTEXT

Patients with suspected deep vein thrombosis (DVT) of the lower extremities are usually investigated with ultrasonography either by the proximal veins (2-point ultrasonography) or the entire deep vein system (whole-leg ultrasonography). The latter approach is thought to be better based on its ability to detect isolated calf vein thrombosis; however, it requires skilled operators and is mainly available only during working hours. No randomized comparisons are yet available evaluating the relative values of these 2 strategies.

OBJECTIVE

To assess if the 2 diagnostic strategies are equivalent for the management of symptomatic outpatients with suspected DVT of the lower extremities.

DESIGN, SETTING, AND PATIENTS

A prospective, randomized, multicenter study of consecutive symptomatic outpatients (n = 2465) with a first episode of suspected DVT of the lower extremities who were randomized to undergo 2-point or whole-leg ultrasonography. Data were taken from ultrasound laboratories of 14 Italian universities or civic hospitals between January 1, 2003, and December 21, 2006. Patients with normal ultrasound findings were followed up for 3 months, with study completion on March 20, 2007.

MAIN OUTCOME MEASURE

Objectively confirmed 3-month incidence of symptomatic venous thromboembolism in patients with an initially normal diagnostic workup.

RESULTS

Of 2465 eligible patients, 345 met 1 or more exclusion criteria and 22 refused to participate; therefore, 2098 patients were randomized to either 2-point (n = 1045) or whole-leg (n = 1053) ultrasonography. Symptomatic venous thromboembolism occurred in 7 of 801 patients (incidence, 0.9%; 95% confidence interval [CI], 0.3%-1.8%) in the 2-point strategy group and in 9 of 763 patients (incidence, 1.2%; 95% CI, 0.5%-2.2%) in the whole-leg strategy group. This met the established equivalence criterion (observed difference, 0.3%;95% CI, -1.4% to 0.8%).

CONCLUSION

The 2 diagnostic strategies are equivalent when used for the management of symptomatic outpatients with suspected DVT of the lower extremities.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00353093.

Prevalence of Pulmonary Embolism among Patients Hospitalized for Syncope

BACKGROUND

The prevalence of pulmonary embolism among patients hospitalized for syncope is not well documented, and current guidelines pay little attention to a diagnostic workup for pulmonary embolism in these patients.

METHODS

We performed a systematic workup for pulmonary embolism in patients admitted to 11 hospitals in Italy for a first episode of syncope, regardless of whether there were alternative explanations for the syncope. The diagnosis of pulmonary embolism was ruled out in patients who had a low pretest clinical probability, which was defined according to the Wells score, in combination with a negative d-dimer assay. In all other patients, computed tomographic pulmonary angiography or ventilation-perfusion lung scanning was performed.

RESULTS

A total of 560 patients (mean age, 76 years) were included in the study. A diagnosis of pulmonary embolism was ruled out in 330 of the 560 patients (58.9%) on the basis of the combination of a low pretest clinical probability of pulmonary embolism and negative d-dimer assay. Among the remaining 230 patients, pulmonary embolism was identified in 97 (42.2%). In the entire cohort, the prevalence of pulmonary embolism was 17.3% (95% confidence interval, 14.2 to 20.5). Evidence of an embolus in a main pulmonary or lobar artery or evidence of perfusion defects larger than 25% of the total area of both lungs was found in 61 patients. Pulmonary embolism was identified in 45 of the 355 patients (12.7%) who had an alternative explanation for syncope and in 52 of the 205 patients (25.4%) who did not.

CONCLUSIONS

Pulmonary embolism was identified in nearly one of every six patients hospitalized for a first episode of syncope. (Funded by the University of Padua; PESIT ClinicalTrials.gov number, NCT01797289 .).

Long-term outcomes of patients with cerebral vein thrombosis: a multicenter study

BACKGROUND

Little information is available on the long-term clinical outcome of cerebral vein thrombosis (CVT).

OBJECTIVES AND METHODS

In an international, retrospective cohort study, we assessed the long-term rates of mortality, residual disability and recurrent venous thromboembolism (VTE) in a cohort of patients with a first CVT episode.

RESULTS

Seven hundred and six patients (73.7% females) with CVT were included. Patients were followed for a total of 3171 patient-years. Median follow-up was 40 months (range 6, 297 months). At the end of follow-up, 20 patients had died (2.8%). The outcome was generally good: 89.1% of patients had a complete recovery (modified Rankin Score [mRS] 0-1) and 3.8% had a partial recovery and were independent (mRS 2). Eighty-four per cent of patients were treated with oral anticoagulants and the mean treatment duration was 12 months. CVT recurred in 31 patients (4.4%), and 46 patients (6.5%) had a VTE in a different site, for an overall incidence of recurrence of 23.6 events per 1000 patient-years (95% confidence Interval [CI] 17.8, 28.7) and of 35.1 events/1000 patient-years (95% CI, 27.7, 44.4) after anticoagulant therapy withdrawal. A previous VTE was the only significant predictor of recurrence at multivariate analysis (hazard ratio [HR] 2.70; 95% CI 1.25, 5.83).

CONCLUSIONS

The long-term risk of mortality and recurrent VTE appears to be low in patients who survived the acute phase of CVT. A previous VTE history independently predicts recurrent events.

Optimal Duration of Low Molecular Weight Heparin for the Treatment of Cancer-Related Deep Vein Thrombosis: The Cancer-DACUS Study

Purpose

We evaluated the role of residual vein thrombosis (RVT) to assess the optimal duration of anticoagulants in patients with cancer who have deep vein thrombosis (DVT) of the lower limbs.

Patients and Methods

Patients with active cancer and a first episode of DVT treated with low molecular weight heparin (LMWH) for 6 months were eligible. Patients were managed according to RVT findings: those with RVT were randomly assigned to continue LMWH for an additional 6 months (group A1) or to discontinue it (group A2), and patients without RVT stopped LMWH (group B). The primary end point was recurrent venous thromboembolism (VTE) during the 1 year after disconinuation of LMWH, and the secondary end point was major bleeding. Analyses are from the time of random assignment.

Results

Between October 2005 and April 2010, 347 patients were enrolled. RVT was detected in 242 patients (69.7%); recurrence occurred in 22 of the 119 patients in group A1compared with 27 of 123 patients in group A2. The adjusted hazard ratio (HR) for group A2 versus A1 was 1.37 (95% CI, 0.7 to 2.5; P = .311). Three of the 105 patients in group B developed recurrent VTE; adjusted HR for group A1 versus B was 6.0 (95% CI, 1.7 to 21.2; P = .005). Three major bleeding events occurred in group A1, and two events each occurred in groups A2 and B. The HR for major bleeding in group A1 versus group A2 was 3.78 (95% CI, 0.77 to 18.58; P = .102). Overall, 42 patients (12.1%) died during follow-up as a result of cancer progression.

Conclusion

In patients with cancer with a first DVT, treated for 6 months with LMWH, absence of RVT identifies a population at low risk for recurrent thrombotic events. Continuation of LMWH in patients with RVT up to 1 year did not reduce recurrent VTE.

Impact of residual pulmonary obstruction on the long-term outcome of patients with pulmonary embolism

The impact of residual pulmonary obstruction on the outcome of patients with pulmonary embolism is uncertain.We recruited 647 consecutive symptomatic patients with a first episode of pulmonary embolism, with or without concomitant deep venous thrombosis. They received conventional anticoagulation, were assessed for residual pulmonary obstruction through perfusion lung scanning after 6 months and then were followed up for up to 3 years. Recurrent venous thromboembolism and chronic thromboembolic pulmonary hypertension were assessed according to widely accepted criteria.Residual pulmonary obstruction was detected in 324 patients (50.1%, 95% CI 46.2-54.0%). Patients with residual pulmonary obstruction were more likely to be older and to have an unprovoked episode. After a 3-year follow-up, recurrent venous thromboembolism and/or chronic thromboembolic pulmonary hypertension developed in 34 out of the 324 patients (10.5%) with residual pulmonary obstruction and in 15 out of the 323 patients (4.6%) without residual pulmonary obstruction, leading to an adjusted hazard ratio of 2.26 (95% CI 1.23-4.16).Residual pulmonary obstruction, as detected with perfusion lung scanning at 6 months after a first episode of pulmonary embolism, is an independent predictor of recurrent venous thromboembolism and/or chronic thromboembolic pulmonary hypertension.

A randomized double-blind study of low-molecular-weight heparin (parnaparin) for superficial vein thrombosis: STEFLUX (Superficial ThromboEmbolism and Fluxum)

BACKGROUND

Optimal doses and duration of low-molecular-weight heparin (LMWH) for the treatment of superficial vein thrombosis (SVT) are still uncertain.

OBJECTIVES

To compare the efficacy and safety of different doses and durations of LMWH parnaparin for symptomatic lower limb SVT.

PATIENTS AND METHODS

Outpatients with at least a 4-cm-long SVT of long or short saphenous veins or their collaterals were randomized to receive parnaparin either 8500 UI once daily ( o.d.) for 10 days followed by placebo for 20 days (group A) or 8500 UI o.d. for 10 days followed by 6400 UI once daily (o.d.) for 20 days (group B) or 4250 UI o.d. for 30 days (group C) in a double-blind fashion in 16 clinics. Primary outcome was the composite of symptomatic and asymptomatic deep vein thrombosis (DVT), symptomatic pulmonary embolism (PE) and relapse and/or symptomatic or asymptomatic SVT recurrence in the first 33 days with 60 days follow-up.

RESULTS

Among 664 patients, primary outcome occurred in 33/212 (15.6%), 4/219 (1.8%) and 16/217 (7.3%) subjects in groups A, B and C, respectively (B vs. A: absolute risk reduction [ARR]: 13.7%, 95% confidence intervals [CI]: 8-18.9 P<0.001; B vs. C: ARR: 5.5%; 95% CI: 1.6-9.4 P= 0.011; C vs. A: ARR: 8.2%, 95% CI: 2-14 P=0.012). During days 0-93, the event rate was higher in group A (22.6%) than either in group B (8.7%; P=0.001) or C (14.3%, P=0.034). No major hemorrhages occurred.

CONCLUSIONS

An intermediate dose of parnaparin for 30 days is superior to either a 30-day prophylactic dose or a 10-day intermediate dose for lower limb SVT treatment.

A prospective validation of the Bova score in normotensive patients with acute pulmonary embolism

BACKGROUND

The Bova score has shown usefulness in the identification of intermediate-high risk patients with acute pulmonary embolism (PE), but lacks prospective validation. The aim of this study was to prospectively validate the Bova score in different settings from the original derivation cohort.

METHODS

Consecutive, normotensive patients with acute PE recruited at 13 academic or general hospitals were stratified, using their baseline data, into the three Bova risk stages (I-III). The primary outcome was the 30-day composite of PE-related mortality, hemodynamic collapse and non-fatal PE recurrences in the three risk categories.

RESULTS

In the study period, 639 patients were enrolled. The primary end point occurred in 45 patients (7.0%; 95% Confidence Intervals, 5.2%-9.3%). Risk stage correlated with the PE-related complication rate (stage I, 2.9%; stage II, 17%; stage III, 27%). Patients classified as stage III by the Bova score had a 6.5-fold increased risk for adverse outcomes (3.1-13.5, p < 0.001) compared with stages I and II combined. Rescue thrombolysis increased from stage I to stage III (0.6%, 12% and 15% respectively). All-cause mortality (5.3%) did not substantially differ among the stages.

CONCLUSIONS

The Bova score accurately stratifies normotensive patients with acute PE into stages of increasing risk of 30-day PE-related complications.

The risk of post-thrombotic syndrome in patients with proximal deep vein thrombosis treated with the direct oral anticoagulants

The novel direct oral anticoagulants (DOAC) have been shown to be at least as effective as and safer than conventional anticoagulants for the initial and long-term treatment of venous thromboembolic disorders. However, the rate of post-thrombotic syndrome (PTS) in patients with deep-vein thrombosis (DVT) treated with the DOACs is unknown. With the adoption of the Villalta scale, we assessed the rate of PTS at the end of the follow-up period in a consecutive series of 309 outpatients with acute proximal DVT who had received at least 3 months of treatment with a DOAC and had been followed-up for up to 3 years. The rate of PTS development was compared with that recorded in a historical cohort of 1036 consecutive patients who had been treated with vitamin K antagonists (VKA) and had received a similar follow-up examination. Logistic regression analysis, including propensity scoring to adjust for differing probabilities of undergoing VKA/DOAC, was used to identify predictors of PTS. PTS developed in 87 patients (28.2%) treated with the DOACs (severe in 12), and in 443 patients (42.8%) treated with VKAs (severe in 61). After adjusting for estimated propensity score, age, gender, concomitant symptoms of pulmonary embolism, duration of anticoagulation and development of residual vein thrombosis, the risk of PTS in the DOAC-treated patients was reduced by 54% in comparison to patients treated with conventional anticoagulation (odds ratio 0.46; 95% CI 0.33 to 0.63). We conclude that in comparison to VKAs, the use of the direct oral anticoagulants has the potential to offer a more favorable prognosis in terms of PTS development.

General Practitioner-Performed Compression Ultrasonography for Diagnosis of Deep Vein Thrombosis of the Leg: A Multicenter, Prospective Cohort Study

BACKGROUND

Patients with suspected deep vein thrombosis (DVT) of the lower limb represent a diagnostic dilemma for general practitioners. Compression ultrasonography (US) is universally recognized as the best test of choice. We assessed the diagnostic accuracy of compression US performed by general practitioners given short training in the management of symptomatic proximal DVT.

METHODS

From May 2014 to May 2016, we evaluated in a multicenter, prospective cohort study all consecutive outpatients with suspected DVT; bilateral proximal lower limb compression US was performed by general practitioners and by physicians expert in vascular US, each group blinded to the other's findings. In all examinations with a negative or nondiagnostic result, compression US was repeated by the same operator after 5 to 7 days. Inter-observer agreement and accuracy were calculated.

RESULTS

We enrolled a total of 1,107 patients. The expert physicians diagnosed DVT in 200 patients, corresponding to an overall prevalence of 18.1% (95% CI, 15.8%-20.3%). The agreement between the trained general practitioners and the experts was excellent (Cohen κ = 0.86; 95% CI, 0.84-0.88). Compression US performed by general practitioners had a sensitivity of 90.0% (95% CI, 88.2%-91.8%) and a specificity of 97.1% (95% CI, 96.2%-98.1%) with a diagnostic accuracy for DVT of 95.8% (95% CI, 94.7%-97.0%).

CONCLUSIONS

Our results suggest that, even in hands of physicians not expert in vascular US, compression US can be a reliable tool in the diagnosis of DVT. We found that the sensitivity achieved by general practitioners appeared suboptimal, however, so future studies should evaluate the implementation of proper training strategies to maximize skill.

Clinical outcomes during anticoagulant therapy in fragile patients with venous thromboembolism

BACKGROUND

Subgroup analyses from randomized trials suggested favorable results for the direct oral anticoagulants in fragile patients with venous thromboembolism (VTE). The frequency and natural history of fragile patients with VTE have not been studied yet.

OBJECTIVES

To compare the clinical characteristics, treatment and outcomes during the first 3 months of anticoagulation in fragile vs non-fragile patients with VTE.

METHODS

Retrospective study using consecutive patients enrolled in the RIETE (Registro Informatizado Enfermedad TromboEmbolica) registry. Fragile patients were defined as those having age ≥75 years, creatinine clearance (CrCl) levels ≤50 mL/min, and/or body weight ≤50 kg.

RESULTS

From January 2013 to October 2016, 15 079 patients were recruited. Of these, 6260 (42%) were fragile: 37% were aged ≥75 years, 20% had CrCl levels ≤50 mL/min, and 3.6% weighed ≤50 kg. During the first 3 months of anticoagulant therapy, fragile patients had a lower risk of VTE recurrences (0.78% vs 1.4%; adjusted odds ratio [OR]: 0.52; 95% confidence intervals [CI]: 0.37-0.74) and a higher risk of major bleeding (2.6% vs 1.4%; adjusted OR: 1.41; 95% CI: 1.10-1.80), gastrointestinal bleeding (0.86% vs 0.35%; adjusted OR: 1.84; 95% CI: 1.16-2.92), haematoma (0.51% vs 0.07%; adjusted OR: 5.05; 95% CI: 2.05-12.4), all-cause death (9.2% vs 3.5%; adjusted OR: 2.02; 95% CI: 1.75-2.33), or fatal PE (0.85% vs 0.35%; adjusted OR: 1.77; 95% CI: 1.10-2.85) than the non-fragile.

CONCLUSIONS

In real life, 42% of VTE patients were fragile. During anticoagulation, they had fewer VTE recurrences and more major bleeding events than the non-fragile.

Findings from a multicentre, observational study on reproductive outcomes in women with unexplained recurrent pregnancy loss: the OTTILIA registry

STUDY QUESTION

What evaluation and care is offered to women after unexplained recurrent pregnancy loss (RPL) or intra-uterine foetal death (IUFD) and what are the reproductive outcomes?

SUMMARY ANSWER

Women are assessed for thrombophilia and often treated with low-molecular weight heparin (LMWH) and/or low-dose aspirin (ASA).

WHAT IS KNOWN ALREADY

Randomized controlled trials (RCTs) on possible efficacy of heparins and/or aspirin have been inconclusive due to limited power to detect a difference and patient heterogeneity.

STUDY DESIGN, SIZE, DURATION

Prospective multicentre cohort study performed in 12 hospitals in three countries between 2012 and 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All consecutive pregnant women with recurrent PL (≥3 losses or 2 losses in the presence of at least one euploid foetal karyotype) or at least one IUFD. Eligible women may have undergone thrombophilia testing before conception, at the discretion of local providers. The possible assignment of women to treatments (such as LMWH) was not decided a priori but was determined based on the responsible provider's current practice. Aims of the study were: (i) to evaluate factors associated with pregnancy outcome; (ii) to compare clinical management strategies in women with and without a subsequent successful pregnancy; and (iii) to evaluate characteristics of women who may benefit from antithrombotic therapy. A propensity score matching method was used to balance the differences in baseline characteristics.

MAIN RESULTS AND THE ROLE OF CHANCE

A matched sample of 265 pregnant women was analysed, with all undergoing thrombophilia screening; 103 out of 119 (86.6%) with and 98/146 (67.1%) without thrombophilia were prescribed with LMWH and/or ASA. Overall, live-births were recorded in 204 cases (77%), PL or IUFD in 61 (23%) pregnancies. Logistic regression showed a significant interaction between thrombophilia and treatment with LMWH (P = 0.03). Findings from sensitivity analysis showed odds ratio (OR) for pregnancy loss in women with inherited or acquired thrombophilia in absence of any treatment was 2.9 (95% CI, 1.4-6.1); the administration of LMWH (with or without ASA) was associated with higher odds of live-birth (OR, 10.6; 95% CI, 5.0-22.3). Furthermore, in women without thrombophilia, the odds of live-birth was significantly and independently associated with LMWH prophylaxis (alone or in association with ASA) (OR, 3.6; 95% CI, 1.7-7.9).

LIMITATIONS, REASONS FOR CAUTION

While the propensity score matching allows us to balance the differences in baseline characteristics, it does not eliminate all confounding.

WIDER IMPLICATIONS OF THE FINDINGS

Antithrombotic prophylaxis during pregnancy may be effective in women with otherwise unexplained PL or IUFD, and even more useful in those with thrombophilia.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by Italian Ministry of Health (Ricerca Corrente 2018-2020). Dr G.P. has received research grant support from Bristol Myers Squibb/Pfizer Alliance, Janssen, Boston Scientific Corporation, Bayer, and Portola and consultant fees from Amgen and Agile Therapeutics. Dr E.G. has received consultant fees from Italfarmaco and Sanofi. All other authors declare that they have no conflict of interest.

TRIAL REGISTRATION NUMBER

NCT02385461.

Residual vein thrombosis and serial D-dimer for the long-term management of patients with deep venous thrombosis

BACKGROUND

The optimal long-term strategy for preventing recurrent venous thromboembolism (VTE) in patients with deep-vein thrombosis (DVT) is uncertain.

METHODS

In 620 consecutive outpatients with a first proximal DVT who had completed at least three months of anticoagulation (unprovoked in 483, associated with minor risk factors in 137), the ultrasound presence of residual vein thrombosis (RVT) was assessed and defined as an incompressibility of at least 4mm. In 517 patients without RVT and with negative D-dimer, anticoagulation was stopped and D-dimer was repeated after one and three months. Anticoagulation was resumed in 63 of the 72 patients in whom D-dimer reverted to positivity.

RESULTS

During a mean follow-up of three years, recurrent VTE developed in 40 (7.7%) of the 517 patients, leading to an annual rate of 3.6% (95% CI, 2.6 to 4.9): 4.1% (95% CI, 2.9 to 5.7) in individuals with unprovoked DVT, and 2.2% (95% CI, 1.1 to 4.5) in those with DVT associated with minor risk factors. Of the 233 males with unprovoked DVT, 17 (7.3%) developed events in the first year of follow-up. Major bleeding complications occurred in 8 patients while on anticoagulation, leading to an annual rate of 1.2% (95% CI, 0.6 to 2.4).

CONCLUSIONS

Discontinuing anticoagulation in patients with a first episode of proximal DVT based on the assessment of RVT and serial D-dimer leads to an overall annual rate of recurrent VTE lower than 5.0%, which is the rate deemed as acceptable by the Subcommittee on Control of Anticoagulation of the ISTH. However, in males with unprovoked DVT there is room for further improving the long-term strategy of VTE prevention. (ClinicalTrials.gov number, NCT01285661).

Age-adjusted D-dimer to rule out deep vein thrombosis: findings from the PALLADIO algorithm

Essentials The accuracy of the age-adjusted D-dimer in suspected venous thromboembolism is still debated. We assessed the performance of age-adjusted D-dimer combined with the PALLADIO algorithm. The age-adjusted threshold can reduce the need for imaging tests compared to the fixed cut-off. The safety of this approach should be confirmed in large management studies.

SUMMARY

Background Age-adjusted D-dimer has been proposed to increase specificity for the diagnosis of venous thromboembolism (VTE). However, the accuracy of this threshold has been recently questioned. Objectives To assess the diagnostic performance of age-adjusted D-dimer combined with clinical pretest probability (PTP) in patients with suspected deep vein thrombosis (DVT). Methods PALLADIO (NCT01412242) was a multicenter management study that validated a new diagnostic algorithm, incorporating PTP, D-dimer (using the manufacturer's cut-off) and limited or extended compression ultrasonography (CUS) in outpatients with clinically suspected DVT. Patients with unlikely PTP and negative D-dimer had DVT ruled out without further testing (group 1); patients with likely PTP or positive D-dimer underwent limited CUS (group 2); patients with likely PTP and positive D-dimer underwent extended CUS (group 3). Patients with DVT ruled out at baseline had a 3-month follow-up. In this post-hoc analysis we evaluated age-adjusted D-dimer cut-off (defined as age times 10 μg L-1 , or age times 5 μg L-1 for D-dimers with a lower manufacturer's cut-off, in patients > 50 years). Results In total, 1162 patients were enrolled. At initial visit, DVT was detected in 4.0% of patients in group 2 and 53.0% in group 3. The age-adjusted D-dimer, compared with the fixed cut-off, resulted in 5.1% (95% CI, 4.0-6.5%) reduction of CUS. The incidence of symptomatic VTE during follow-up was: 0.24% (95% CI, 0.04-1.37) in group 1; 1.12% (95% CI, 0.44-2.85) in group 2; and 1.89% (95% CI, 0.64-5.40) in group 3. Conclusions The PALLADIO algorithm using age-adjusted D-dimer slightly decreased the number of required imaging tests, but this approach should be confirmed in large management studies.

Rivaroxaban treatment for six weeks versus three months in patients with symptomatic isolated distal deep vein thrombosis: randomised controlled trial

OBJECTIVE

To compare two different treatment durations of rivaroxaban in patients with symptomatic isolated distal deep vein thrombosis (DVT).

DESIGN

Randomised, double blind, placebo controlled clinical trial.

SETTING

28 outpatient clinics specialising in venous thromboembolism.

PARTICIPANTS

402 adults (≥18 years) with symptomatic isolated distal DVT.

INTERVENTIONS

After receiving standard dose rivaroxaban for six weeks, participants were randomly assigned to receive rivaroxaban 20 mg or placebo once daily for an additional six weeks. Follow-up was for 24 months from study inclusion.

MAIN OUTCOMES MEASURES

The primary efficacy outcome was recurrent venous thromboembolism during follow-up after randomisation, defined as the composite of progression of isolated distal DVT, recurrent isolated distal DVT, proximal DVT, symptomatic pulmonary embolism, or fatal pulmonary embolism. The primary safety outcome was major bleeding after randomisation until two days from the last dose of rivaroxaban or placebo. An independent committee adjudicated the outcomes.

RESULTS

200 adults were randomised to receive additional rivaroxaban treatment and 202 to receive placebo. Isolated distal DVT was unprovoked in 81 (40%) and 86 (43%) patients, respectively. The primary efficacy outcome occurred in 23 (11%) patients in the rivaroxaban arm and 39 (19%) in the placebo arm (relative risk 0.59, 95% confidence interval 0.36 to 0.95; P=0.03, number needed to treat 13, 95% confidence interval 7 to 126). Recurrent isolated distal DVT occurred in 16 (8%) patients in the rivaroxaban arm and 31 (15%) in the placebo arm (P=0.02). Proximal DVT or pulmonary embolism occurred in seven (3%) patients in the rivaroxaban arm and eight (4%) in the placebo arm (P=0.80). No major bleeding events occurred.

CONCLUSIONS

Rivaroxaban administered for six additional weeks in patients with isolated distal DVT who had an uneventful six week treatment course reduces the risk of recurrent venous thromboembolism, mainly recurrent isolated distal DVT, over a two year follow-up without increasing the risk of haemorrhage.

TRIAL REGISTRATION

EudraCT 2016-000958-36; ClinicalTrials.gov NCT02722447.

The negative predictive value of D-dimer on the risk of recurrent venous thromboembolism in patients with multiple previous events: a prospective cohort study (the PROLONG PLUS study)

The optimal duration of anticoagulation after recurrent venous thromboembolism(VTE) is poorly established [1,2]. Recent studies suggested that D-dimer may identify patients at low risk of recurrence after a first VTE [3,4]. In a pilot, prospective, cohort study we aimed to assess the negative predictive value of D-dimer in patients with recurrent VTE. Patients with negative D-dimer while on treatment stopped anti coagulation and underwent repeated testing after 7, 15, and 30 days; treatment was resumed if D-dimer turned positive and permanently stopped if it remained negative. The study was interrupted after the enrolment of 75 patients. At that time, treating physicians decided treatment resumption in 12.2% of the patients, but the majority of events were distal or superficial vein thromboses. The rate of objectively documented recurrent proximal deep vein thrombosis (DVT) and/or pulmonary embolism (PE) was 2.56% (95% CI 0.13, 15.07%) in the 39 patients with persistently negative D-dimer at 30 days, for an annual incidence of VTE of 5.65 events/100 patient/years. These preliminary findings suggest that negative D-dimer may identify patients with history of previous VTE at low risk of recurrences, but this approach should be tested in larger trials in highly selected patients.

D-dimer levels during and after anticoagulation withdrawal in patients with venous thromboembolism treated with non-vitamin K anticoagulants

Background

D-dimer levels measured during and after vitamin K antagonist withdrawal may be used in clinical practice to assess the individual risk of recurrent venous thromboembolism. Currently, direct oral anticoagulants (DOACs) are frequently used in venous thromboembolism treatment; however, their pharmacokinetics and pharmacodynamics characteristics are completely different than vitamin K antagonists. The present study aimed at comparing the results of D-dimer levels during and after anticoagulation withdrawal in patients with venous thromboembolism treated with DOACs or warfarin.

Material and methods

D-dimer levels were measured in 527 patients (“cases”) during DOACs treatment (T0) and after 15 (T15), 30 (T30), 60 (T60) and 90 (T90) days after their discontinuation and in 527 patients (“controls”) enrolled in the DULCIS study (all treated with warfarin), matched for sex, age (+/-3 y), type of D-dimer assay and site of venous thromboembolism. Both cases and controls received anticoagulant treatment after a first venous thromboembolism event that was unprovoked or associated with weak risk factors.

Results

The rate of positive D-dimer results was significantly higher in cases than in controls at T0 (10.8% vs 5.1%, p = 0.002) and at T30 (18.8% vs 11.8%, p = 0.019), as well as at the other time-points, though not statistically significant.

Conclusion

D-dimer levels during and after stopping an anticoagulant treatment for a venous thromboembolism episode differ between patients treated with a DOAC than in those treated with warfarin. Specifically designed prospective studies are warranted to reassess the use of D-dimer as predictor of the risk of recurrent venous thromboembolism in patients treated with DOACs.

An association between residual vein thrombosis and subclinical atherosclerosis: Cross-sectional study

BACKGROUND

The association between venous and arterial thrombotic disorders is still unclear. We assessed the association between residual vein thrombosis (RVT) and subclinical atherosclerosis in a cohort of patients with unprovoked (or associated with weak risk factors) proximal deep-vein thrombosis (DVT).

METHODS

In a multicenter cross-sectional study, consecutive patients over 40years free from atherosclerotic disorders received the ultrasound assessment of the leg vein system and that of carotid arteries approximately three months after an episode of proximal DVT. In each center the evaluation was done by two independent assessors. The presence of RVT was defined as the incompressibility of at least 4mm in either the popliteal or the common femoral vein, and that of subclinical atherosclerosis as the presence of increased (>0.9mm) intima-media tickness (IMT) and/or carotid plaques.

RESULTS

Out of 252 patients (mean age, 67; males, 53%; unprovoked, 77%), the presence of RVT was found in 139 (55.2%). An increased IMT was shown in 76 (54.7%) patients with and in 35 (31.0%) without RVT (p<0.001). At least one carotid plaque was found in 80 (57.6%) patients with and in 36 (31.9%) without RVT (p<0.001). After adjusting for the baseline characteristics, the odds ratio of subclinical atherosclerosis (increased IMT and/or carotid plaques) was 2.8 (95% CI, 1.6 to 4.7).

CONCLUSION

The ultrasound detection of RVT after an episode of proximal DVT that is either unprovoked or triggered by weak risk factors is associated with a higher prevalence of subclinical atherosclerosis. These findings may have implications for patient prognosis.

D-dimer levels and risk of recurrence following provoked venous thromboembolism: findings from the RIETE registry

BACKGROUND

Patients with venous thromboembolism (VTE) secondary to transient risk factors may develop VTE recurrences after discontinuing anticoagulation. Identifying at-risk patients could help to guide the duration of therapy.

METHODS

We used the RIETE database to assess the prognostic value of d-dimer testing after discontinuing anticoagulation to identify patients at increased risk for recurrences. Transient risk factors were classified as major (postoperative) or minor (pregnancy, oestrogen use, immobilization or recent travel).

RESULTS

In December 2018, 1655 VTE patients with transient risk factors (major 460, minor 1195) underwent d-dimer measurements after discontinuing anticoagulation. Amongst patients with major risk factors, the recurrence rate was 5.74 (95% CI: 3.19-9.57) events per 100 patient-years in those with raised d-dimer levels and 2.68 (95% CI: 1.45-4.56) in those with normal levels. Amongst patients with minor risk factors, the rates were 7.79 (95% CI: 5.71-10.4) and 3.34 (95% CI: 2.39-4.53), respectively. Patients with major risk factors and raised d-dimer levels (n = 171) had a nonsignificantly higher rate of recurrences (hazard ratio [HR]: 2.14; 95% CI: 0.96-4.79) than those with normal levels. Patients with minor risk factors and raised d-dimer levels (n = 382) had a higher rate of recurrences (HR: 2.34; 95% CI: 1.51-3.63) than those with normal levels. On multivariate analysis, raised d-dimers (HR: 1.74; 95% CI: 1.09-2.77) were associated with an increased risk for recurrences in patients with minor risk factors, not in those with major risk factors.

CONCLUSIONS

Patients with raised d-dimer levels after discontinuing anticoagulant therapy for VTE provoked by a minor transient risk factor were at an increased risk for recurrences.

Rationale and design of two prospective, multicenter, observational studies on reproductive outcome in women with recurrent failures after spontaneous or assisted conception: OTTILIA and FIRST registries

Background

Spontaneous pregnancy loss and implantation failure after assisted reproductive technologies (ART) are very common occurrences. Although 50–60% of all cases remains unexplained, various predisposing factors, including thrombophilias, have been identified. Thus, the potential benefit of a prophylaxis with low-molecular-weight heparins in improving outcomes has been often investigated over the years. However, the majority of studies are observational and results from randomized clinical trials (RCTs) are inconclusive, probably due to heterogeneity and limited sample size. To cover these unmet needs and to have further data mainly based on the real-life clinical management, we designed these multicenter registries.

Methods

OTTILIA (Observational sTudy on antiThrombotic prevention in thrombophILIA and pregnancy loss) and FIRST (recurrent Failures in assIsted Reproductive Techniques) registries are two prospective, multicenter, observational studies to evaluate pregnancy or ART outcomes in consecutive women with previous reproductive failures after spontaneous or assisted conception, respectively. All enrolled women are observed from their first visit after positive pregnancy test (OTTILIA) or before commencing a new ART cycle (FIRST) until the end of pregnancy or ART procedure (negative pregnancy test/end of pregnancy, if successful cycle), respectively. Data are collected by means of questionnaires and recorded in a central database. Follow-up investigations are performed during hospital stay, routine clinical follow-up visits or telephone interviews. Primary outcome is live birth rate in the OTTILIA register and clinical pregnancy rate in the FIRST.

Discussion

Although RCTs are the ‘gold standard’ for evaluating treatment outcomes, we believe that our registries represent a valid alternative in improving knowledge on mechanisms involved in reproductive failures and supporting future clinical decisions.

Trial registration

NCT 02385461, retrospectively registered 5 March 2015 (OTTILIA); NCT 02685800, registered 10 February 2016 (FIRST).

Anticoagulation in Italian patients with venous thromboembolism and thrombophilic alterations: findings from START2 register study

BACKGROUND

Randomised control trials have assessed the efficacy and safety of direct oral anticoagulants in the prophylaxis and treatment of venous thromboembolism (VTE). Positive but limited results have been reported in patients with inherited thrombophilia. Using an Italian, multicentre, prospective registry of consecutive patients presenting with symptomatic, acute VTE, we aimed to assess which factors are involved in making the choice of the drug that best fits the patient's risk profile in a large real-world setting of VTE patients.

MATERIALS AND METHODS

We investigated 4,866 VTE patients who took oral anticoagulants in the period between 2012 and April 2018 to prevent a new thromboembolic episode.

RESULTS

The large majority of patients who underwent thrombophilic screening, regardless of the results obtained, were prescribed direct oral anticoagulants rather than conventional anticoagulant therapy (p<0.001). During anticoagulation, bleeding events occurred more frequently in patients on conventional anticoagulant therapy (4.2%) than in those receiving direct oral anticoagulants (1.8%) and an increase in bleeding events was observed in patients who tested positive at the thrombophilic screening. Overall, a higher number of recurrent VTE was observed in patients not screened for thrombophilia (n=36; 1.7%) than in those screened (n=20; 0.7%; adjusted odds ratio: 2.2; 95% confidence interval: 1.2-4.1).

DISCUSSION

The present data confirm previous findings from other post-marketing registries and suggest that the choice of oral anticoagulation is strongly driven by patients' characteristics and VTE manifestations. Factors leading to the prescription of thrombophilic screening may identify a patient with a lower risk of VTE recurrence during anticoagulation.

Prior thromboprophylaxis and outcome in patients experiencing acute venous thromboembolism after an acute medical illness

BACKGROUND

Even despite the use of thromboprophylaxis, some patients with an acute medical illness develop symptomatic venous thromboembolism (VTE). It is unclear whether the outcome in these patients is different in those in whom prophylaxis was not prescribed.

PATIENTS AND METHODS

We used the RIETE (Registro Informatizado Enfermedad TromboEmbolica) database to compare the 3-month outcome (death, fatal pulmonary embolism, VTE recurrences, major bleeding) of patients with acute VTE after immobilization for an acute medical disease, according to the use of prophylaxis.

RESULTS

Thromboprophylaxis was prescribed in 1313 (37%) of the 3527 patients included in August 2014. Acute infection was the most frequent cause of immobilization. Patients who received prophylaxis were more frequently immobilized in hospital than at home (70% vs. 22%), and fewer patients were immobilized for cancer (13% vs. 22%). During the first 3months of treatment, the rates of all-cause death (23 vs. 21%), fatal PE (2.6 vs. 3.1%), VTE recurrences (2.4% vs. 2.8%), and major bleeding (4.2% for both) did not differ between the two groups. Thromboprophylaxis was not associated with each outcome in multivariate analysis.

CONCLUSIONS

The outcome in patients with VTE provoked by medical immobilization was not influenced by the use of thromboprophylaxis during the period of immobility.