Latest advances in the reversal strategies for direct oral anticoagulants.

BACKGROUND: Since the late 2000s, Europe has granted approval for various thrombotic risk-related uses of direct oral anticoagulants (DOACs). Unlike traditional anticoagulants, DOACs do not necessitate routine coagulation monitoring. Nevertheless, clinical practice often encounters bleeding events associated with these medications, making the need for effective reversal strategies evident. OBJECTIVES: The study aims to take stock of current reversal strategies for DOACs, with a particular emphasis on the latest compounds that have been developed or are currently under development. METHODS: For obtaining information regarding the ongoing reversal strategies and the compounds under development, we referred to ClinicalTrials website, PubMed, and Google Scholar. RESULTS: In 2024, two specific antidotes to DOACs have already received approval when reversal of anticoagulation is needed owing to life-threatening or uncontrolled bleeding: idarucizumab that reverses the effects of dabigatran, and andexanet alfa, designed to counteract activated factor X inhibitors such as apixaban and rivaroxaban. Furthermore, ciraparantag, a potential universal reversal agent, is currently in advanced stages of clinical development. Concerns remain regarding the safety of specific reversal agents, especially concerning the risk of thrombosis. Additionally, the cost of these antidotes remains high. Consequently, nonspecific strategies to counteract anticoagulant medications, including activated charcoal, hemodialysis, and concentrates of coagulation factors, still have utility. CONCLUSION: With the validation of specific and nonspecific antidotes, DOACs could supplant traditional oral anticoagulants. This progress represents a significant advancement in anticoagulation therapy. However, ongoing research is crucial to address remaining safety concerns of the specific reversion agents of DOACs in clinical practice.

Management of cancer-associated thromboembolism in vulnerable population.

Although all patients with cancer-associated thrombosis (CAT) have a high morbidity and mortality risk, certain groups of patients are particularly vulnerable. This may expose the patient to an increased risk of thrombotic recurrence or bleeding (or both), as the benefit-risk ratio of anticoagulant treatment may be modified. Treatment thus needs to be chosen with care. Such vulnerable groups include older patients, patients with renal impairment or thrombocytopenia, and underweight and obese patients. However, these patient groups are poorly represented in clinical trials, limiting the available data, on which treatment decisions can be based. Meta-analysis of data from randomised clinical trials suggests that the relative treatment effect of direct oral factor Xa inhibitors (DXIs) and low molecular weight heparin (LMWH) with respect to major bleeding could be affected by advanced age. No evidence was obtained for a change in the relative risk-benefit profile of DXIs compared to LMWH in patients with renal impairment or of low body weight. The available, albeit limited, data do not support restricting the use of DXIs in patients with CAT on the basis of renal impairment or low body weight. In older patients, age is not itself a critical factor for choice of treatment, but frailty is such a factor. Patients over 70 years of age with CAT should undergo a systematic frailty evaluation before choosing treatment and modifiable bleeding risk factors should be addressed. In patients with renal impairment, creatine clearance should be assessed and monitored regularly thereafter. In patients with an eGFR<30mL/min/1.72m2, the anticoagulant treatment may need to be adapted. Similarly, platelet count should be assessed prior to treatment and monitored regularly. In patients with grade 3-4, thrombocytopenia (<50,000 platelets/µL) treatment with a LMWH at a reduced dose should be considered. For patients with CAT and low body weight, standard anticoagulant treatment recommendations are appropriate, whereas in obese patients, apixaban may be preferred.

Anticoagulant treatment of cancer-associated thromboembolism.

Venous thromboembolism (VTE) is a frequent and potentially fatal complication in patients with cancer. During the initial period after the thromboembolic event, a patient receiving anticoagulant treatment is exposed both to a risk of VTE recurrence and also to an elevated bleeding risk conferred by the treatment. For this reason, the choice of anticoagulant is critical. The choice should take into account patient-related factors (such as functional status, age, body mass index, platelet count and renal function), VTE-related factors (such as severity or site), cancer-related factors (such as activity and progression) and treatment-related factors (such as drug-drug interactions), which all potentially influence bleeding risk, and patient preference. These should be evaluated carefully for each patient during a multidisciplinary team meeting. For most patients, apixaban or a low molecular-weight heparin is the most appropriate initial choice for anticoagulant treatment. Such treatment should be offered to all patients with active cancer for at least six months. The patient and treatment should be re-evaluated regularly and anticoagulant treatment changed when necessary. Continued anticoagulant treatment beyond six months is justified if the cancer remains active or if the patient experienced recurrence of VTE in the first six months. In other cases, the interest of continued anticoagulant treatment may be considered on an individual patient basis in collaboration with oncologists.

A framework to characterise the reproducibility of meta-analysis results with its application to direct oral anticoagulants in the acute treatment of venous thromboembolism.

The number of meta-analyses of aggregate data has dramatically increased due to the facility of obtaining data from publications and the development of free, easy-to-use, and specialised statistical software. Even when meta-analyses include the same studies, their results may vary owing to different methodological choices. Assessment of the replication of meta-analysis provides an example of the variation of effect 'naturally' observed between multiple research projects. Reproducibility of results has mostly been reported using graphical descriptive representations. A quantitative analysis of such results would enable (i) breakdown of the total observed variability with quantification of the variability generated by the replication process and (ii) identification of which variables account for this variability, such as methodological quality or the statistical analysis procedures used. These variables might explain systematic mean differences between results and dispersion of the results. To quantitatively characterise the reproducibility of meta-analysis results, a bivariate linear mixed-effects model was developed to simulate both mean results and their corresponding uncertainty. Results were assigned to several replication groups, those assessing the same studies, outcomes, treatment indication and comparisons classified in the same replication group. A nested random effect structure was used to break down the total variability within each replication group and between these groups to enable calculation of an intragroup correlation coefficient and quantification of reproducibility. Determinants of variability were investigated by modelling both mean and variance parameters using covariates. The proposed model was applied to the example of meta-analyses evaluating direct oral anticoagulants in the acute treatment of venous thromboembolism.

Data Monitoring Committees and clinical trials: From scientific justification to organisation.

Clinical trials often last several months or even several years. As the trial progresses, it can be tempting to find out whether the data obtained already answers the question posed at the start of the trial in order to stop inclusions or monitoring earlier. However, knowing and taking into account interim results can sometimes compromise the integrity of the results, which is counterproductive. To minimise this risk and ensure that the treatments are assessed reliably, safety and/or efficacy criteria are monitored during the study by a Data Monitoring Committee. After receiving the results confidentially, the Data Monitoring Committee assesses the benefit/risk ratio of the study treatment and recommends that the trial be continued, modified or terminated. Data Monitoring Committee members issuing these recommendations have an important responsibility: a hasty decision to end the trial may lead to inconclusive results unable to answer the initial question and, inversely, delaying the decision to end the trial may expose the subjects to potentially ineffective or even harmful interventions. The Data Monitoring Committee's task is therefore particularly complex. With this in mind, the round table discussion at the Giens workshops was a chance to review the scientific justification for creating Data Monitoring Committees and to recall the need for their members to receive comprehensive training on the complexities of multiple analyses, confidentiality requirements applying to the results and the need for them to be aware that recommendations to end a trial must be based on data that is robust enough to assess the benefit/risk ratio of the treatment studied.

French guidelines for the treatment of cancer-associated venous thromboembolism - 2023 update.

BACKGROUND: In recent years, knowledge about cancer associated thrombosis has evolved considerably. METHODS: Practical guidelines were drafted on the initiative of the INNOVTE FCRIN Network, led by the French Speaking Society of Respiratory Diseases (SPLF), by a coordinating group, a writing group, and a review group, with the involvement of different scientific societies practicing in various settings. The method followed the "Clinical Practice Guidelines" process of the French National Authority for Health (HAS). RESULTS: After a literature review, guidelines were formulated, improved, and then validated by the working groups. These guidelines addressed multiple aspects of the disease and management from the data of available clinical trials and observational studies : epidemiology, initial treatment, treatment duration, extended treatment, recurrent thrombosis, central venous catheter thrombosis, incidental thrombosis, treatment in case of thrombocytopenia. CONCLUSION: These evidence-based guidelines are intended to guide the practical management of patients with cancer associated thrombosis.

A revisited version of the disputatio for pharmacological training: An educational study.

OBJECTIVE: The disputatio is a pedagogical method existing since the Middle-Ages where students had to debate about a question asked by a "master", exercising their thinking and oratory skills. To move away from traditional vertical teaching methods, the disputatio has been revived by pharmacologists. Thus, for almost three successive years, several groups of young French pharmacologists and therapists confronted their ideas concerning a medical question at a therapeutic impasse. The aim here is to describe the initial feedback received from participants. METHODS: An anonymous questionnaire was sent by email in May 2023 to the participants of the different disputationes of 2019, 2022 and 2023. Participants were asked about different aspects of their feelings before, during and after the disputatio, using the 5-point Likert scale. They were also asked to describe the event in 2 to 5 words. Finally, participants could leave their comments in a free-field and were asked to give an overall satisfaction score out of 10. RESULTS: Out of the 39 participants, 27 (69.2%) answered the questionnaire. Although 50% of respondents reported a feeling of anxiety before participating, most enjoyed the expert talks as well as working with people they did not know. Besides, over 66% reported having underestimated the skills they could share with colleagues from different backgrounds. Over 55% of respondents reported progress in methodology, and over 83% in pharmacology and/or therapeutics. Participants reported an overall satisfaction score of 8.6/10, and the main terms used to describe the event were "sharing", "enriching" and "meeting". CONCLUSION: The disputatio is an innovative training program whose pedagogical and human values were underlined by most of the participants. Beyond pharmacology and therapeutics, the principle of disputatio could be extended to other disciplines, spanning the centuries.

Replication of systematic reviews: is it to the benefit or detriment of methodological quality?

OBJECTIVES: To perform an overview of the overlap of systematic reviews (SRs) assessing direct oral anticoagulants and characterize these reviews in terms of bias and methodological quality (PROSPERO: CRD42022316273). STUDY DESIGN AND SETTING: A PubMed-indexed search was performed from inception to January 31, 2022 to identify SRs evaluating direct oral anticoagulants in patients treated for an acute venous thromboembolism. The risk of bias of these SRs was assessed according to the Risk Of Bias In Systematic reviews tool. Redundancy was defined as overlap in terms of the type of population considered, the interventions compared, and the studies included. RESULTS: A total of 144 SRs were evaluated, of which 26 (18.1%) were classified as original, 87 (60.4%) as conceptual replications, and 31 (21.5%) as excessive replications. The risk of bias was high in 19 (73.1%) of the original SRs, 65 (74.7%) of the conceptual replications, and 21 (67.7%) of the excessive replications. Compared to the original SRs, the overall methodological quality was not improved in either conceptual or excessive replications. CONCLUSION: A large number of SRs was classified as replications; a fifth constituted excessive replications. The replications showed no improvement in overall methodological quality compared to the original SRs.

Impact of wearable device-based interventions with feedback for increasing daily walking activity and physical capacities in cardiovascular patients: a systematic review and meta-analysis of randomised controlled trials.

OBJECTIVE: To systematically review randomised controlled trials (RCTs) using a wearable physical activity monitoring device as an intervention to increase daily walking activity and improve physical capacities in patients with cardiovascular disease (CVD). DESIGN: Systematic review and meta-analysis of RCTs. DATA SOURCES: PubMed, Embase and Web of Science from inception to June 2022. ELIGIBILITY CRITERIA: Randomised controlled studies including patients with CVD over 18 years of age at the end of a cardiac rehabilitation programme comparing an intervention group using a wearable physical activity monitoring device with feedback with usual care or with a control group receiving no feedback on their physical activity and reporting a change in the daily number of steps and/or a change in the distance covered in the 6-minute walk test (6-MWT) or a change in peak oxygen uptake (V̇O2peak) as endpoints. RESULTS: Sixteen RCTs were included. The intervention of wearing a physical activity monitoring device with feedback significantly improved daily number of steps compared with controls (standardised mean difference (SMD) 0.85; 95% CI (0.42; 1.27); p<0.01). The effect was greater when the duration of the intervention was less than 3 months (SMD 1.0; 95% CI (0.18; 1.82); p<0.01) than when the duration of the intervention was 3 months or longer (SMD 0.71; 95% CI (0.27; 1.16); p<0.01), but no significant interaction was found between subgroups (p=0.55). 6-MWT distance and V̇O2peak showed only small effects (SMD 0.34; 95% CI (-0.11; 0.80); p=0.02 and SMD 0.54; 95% CI (0.03; 1.03); p=0.07, respectively). CONCLUSION: The use of wearable physical activity monitoring devices appears to help patients with CVD to increase their daily walking activity and thus their physical activity, particularly in the short term. PROSPERO REGISTRATION NUMBER: CRD42022300423.

Effect of weight-adjusted intermediate-dose versus fixed-dose prophylactic anticoagulation with low-molecular-weight heparin on venous thromboembolism among noncritically and critically ill patients with COVID-19: the COVI-DOSE trial, a multicenter, randomised, open-label, phase 4 trial.

Background: Venous thromboembolism is a major complication of coronavirus disease 2019 (COVID-19). We hypothesized that a weight-adjusted intermediate dose of anticoagulation may decrease the risk of venous thromboembolism COVID-19 patients. Methods: In this multicenter, randomised, open-label, phase 4, superiority trial with blinded adjudication of outcomes, we randomly assigned adult patients hospitalised in 20 French centers and presenting with acute respiratory SARS-CoV-2. Eligible patients were randomly assigned (1:1 ratio) to receive an intermediate weight-adjusted prophylactic dose or a fixed-dose of subcutaneous low-molecular-weight heparin during the hospital stay. The primary outcome corresponded to symptomatic deep-vein thrombosis (fatal) pulmonary embolism during hospitalization (COVI-DOSE ClinicalTrials.gov number: NCT04373707). Findings: Between May 2020, and April 2021, 1000 patients underwent randomisation in medical wards (noncritically ill) (80.1%) and intensive care units (critically ill) (19.9%); 502 patients were assigned to receive a weight-adjusted intermediate dose, and 498 received fixed-dose thromboprophylaxis. Symptomatic venous thromboembolism occurred in 6 of 502 patients (1.2%) in the weight-adjusted dose group and in 10 of 498 patients (2.1%) in the fixed-dose group (subdistribution hazard ratio, 0.59; 95% CI, 0.22-1.63; P = 0.31). There was a twofold increased risk of major or clinically relevant nonmajor bleeding: 5.9% in the weight-adjusted dose group and 3.1% in the fixed-dose group (P = 0.034). Interpretation: In the COVI-DOSE trial, the observed rate of thromboembolic events was lower than expected in patients hospitalized for COVID-19 infection, and the study was unable to show a significant difference in the risk of venous thromboembolism between the two low-molecular-weight-heparin regimens. Funding: French Ministry of Health, CAPNET, Grand-Est Region, Grand-Nancy Métropole.

Antithrombotic therapy and cardiovascular outcomes after transcatheter aortic valve implantation in patients without indications for chronic oral anticoagulation: a systematic review and network meta-analysis of randomized controlled trials.

AIMS: As the antithrombotic regimen that may best prevent ischaemic complications along with the lowest bleeding risk offset following transcatheter aortic valve implantation (TAVI) remains unclear, we aimed to compare the safety and efficacy of antithrombotic regimens in patients without having an indication for chronic oral anticoagulation. METHODS AND RESULTS: We conducted a PROSPERO-registered (CRD42021247924) systematic review and network meta-analysis of randomized controlled trials evaluating post-TAVI antithrombotic regimens up to April 2022. We estimated the relative risk (RR) and 95% confidence intervals (95% CIs) using a random-effects model in a frequentist pairwise and network metanalytic approach. We included seven studies comprising 4006 patients with a mean weighted follow-up of 12.9 months. Risk of all-cause death was significantly reduced with dual antiplatelet therapy (DAPT) compared with low-dose rivaroxaban + 3-month single antiplatelet therapy (SAPT) (RR 0.60, 95% CI 0.41-0.88), while no significant reduction was observed with SAPT vs. DAPT (RR 1.02, 95% CI 0.67-1.58) and SAPT and DAPT compared with apixaban or edoxaban (RR 0.60, 95% CI 0.32-1.14 and RR 0.59, 95% CI 0.34-1.02, respectively). SAPT was associated with a significant reduction of life-threatening, disabling, or major bleeding compared with DAPT (RR 0.45, 95% CI 0.29-0.70), apixaban or edoxaban alone (RR 0.45, 95% CI 0.25-0.79), and low-dose rivaroxaban + 3-month SAPT (RR 0.30, 95% CI 0.16-0.57). There were no differences between the various regimens with respect to myocardial infarction, stroke, or systemic embolism. CONCLUSION: Following TAVI in patients without an indication for chronic oral anticoagulant, SAPT more than halved the risk of bleeding compared with DAPT and direct oral anticoagulant-based regimens without significant ischaemic offset.

Platform trials.

For the past few years, platform trials have experienced a significant increase, recently amplified by the COVID-19 pandemic. The implementation of a platform trial is particularly useful in certain pathologies, particularly when there is a significant number of drug candidates to be assessed, a rapid evolution of the standard of care or in situations of urgent need for evaluation, during which the pooling of protocols and infrastructure optimizes the number of patients to be enrolled, the costs, and the deadlines for carrying out the investigation. However, the specificity of platform trials raises methodological, ethical, and regulatory issues, which have been the subject of the round table and which are presented in this article. The round table was also an opportunity to discuss the complexity of sponsorship and data management related to the multiplicity of partners, funding, and governance of these trials, and the level of acceptability of their findings by the competent authorities.

Enoxaparin versus Placebo to Prevent Symptomatic Venous Thromboembolism in Hospitalized Older Adult Medical Patients.

Enoxaparin to Prevent Venous Thromboembolism in Older AdultsThis trial of thromboprophylaxis in medically ill, hospitalized older adults did not demonstrate that enoxaparin reduced the risk of symptomatic VTE after 1 month. Because the trial was prematurely discontinued, larger trials are needed to definitively address this question.

Adjusted versus fixed doses of LMWHs in trauma patients: A systematic review and meta-analysis.

PURPOSE: Venous thromboembolism (VTE) causes significant morbidity and mortality in patients with traumatic injuries, despite thromboprophylaxis. To decrease both thrombotic and bleeding risks, some authors suggest adjusting the thromboprophylactic doses of low-molecular-weight heparins (LMWH), in particular according to body weight at treatment initiation or to changes in anti-factor Xa level during treatment. Our objective was to estimate in trauma patients the efficacy and safety of such adjustments, compared with the conventional strategy of fixed-dose LMWH thromboprophylaxis. SOURCE: A systematic review and a meta-analysis were conducted to identify and assess randomised control trials and observational studies with prospective enrolment that included trauma patients and compared adjustment of LMWH thromboprophylaxis versus no adjustment. The primary and secondary endpoints were VTE and bleeding, respectively. The Odds Ratio (OR) and 95% Confidence Interval (95% CI) were calculated using the Mantel-Haenszel method. PRINCIPAL FINDINGS: Nine studies were included in the meta-analysis. No significant reduction in the risk of VTE was observed with adjusted doses of LMWH compared with fixed doses when considering only randomised control trials (OR 1.02 [95% CI, 0.09 to 11.6]) or all trials (OR 0.70 [95% CI, 0.34 to 1.42]). Similarly, there was no significant difference in bleeding risk (OR 1.36, 95% CI 0.59 to 3.10). CONCLUSION: This meta-analysis shows that, to date, there is no evidence to justify adjusting LMWH doses, in agreement with the recommendations of the American College of Chest Physicians.

Frequency and predictors for chronic thromboembolic pulmonary hypertension after a first unprovoked pulmonary embolism: Results from PADIS studies.

BACKGROUND: Chronic thromboembolic pulmonary hypertension (CTEPH) is a life-threatening complication of a pulmonary embolism (PE) whose incidence and predictors are not precisely determined. OBJECTIVE: To determine the frequency and predictors for CTEPH after a first unprovoked PE. PATIENTS/METHODS: In a randomized trial comparing an additional 18-month warfarin versus placebo in patients after a first unprovoked PE initially treated with vitamin K antagonist for 6 months, we applied recommended CTEPH screening strategies through an 8-year follow-up to determine cumulative incidence of CTEPH. CTEPH predictors were estimated using Cox models. Pulmonary vascular obstruction (PVO) and systolic pulmonary arterial pressure (sPAP) at PE diagnosis and 6 months were studied by receiver operating curves analysis. All CTEPH cases and whether they were incident or prevalent were adjudicated. RESULTS: During a median follow-up of 8.7 years, nine CTEPH cases were diagnosed among 371 patients, with a cumulative incidence of 2.8% (95% confidence interval [CI] 0.95-4.64), and of 1.31% (95% CI 0.01-2.60) after exclusion of five cases adjudicated as prevalent. At PE diagnosis, PVO > 45% and sPAP > 56 mmHg were associated with CTEPH with a hazard ratio (HR) of 33.00 (95% CI 1.64-667.00, p = .02) and 12.50 (95% CI 2.10-74.80, p < .01), respectively. Age > 65 years, lupus anticoagulant antibodies and non-O blood groups were also predictive of CTEPH. PVO > 14% and sPAP > 34 mmHg at 6 months were associated with CTEPH (HR 63.90 [95% CI 3.11-1310.00, p < .01]and HR 17.2 [95% CI 2.75-108, p < .01]). CONCLUSION: After a first unprovoked PE, CTEPH cumulative incidence was 2.8% during an 8-year follow-up. PVO and sPAP at PE diagnosis and at 6 months were the main predictors for CTEPH diagnosis.

Prevention of Atrial Fibrillation After Atrial Flutter Ablation With Ramipril (from the PREFACE Study).

The clinical efficacy of the inhibitors of the renin-angiotensin-aldosterone system (RAAS) as an upstream therapy for atrial fibrillation (AF) prevention is controversial. No study has itemized so far the role of RAAS inhibitors in AF prevention after atrial flutter (AFL) ablation. This trial aims to investigate the effect of ramipril compared with placebo on AF occurrence in patients hospitalized for AFL ablation without structural heart disease. The Prevention of Atrial Fibrillation by Inhibition Conversion Enzyme (ICE) After Radiofrequency Ablation of Atrial Flutter (PREFACE) trial was a prospective, multicenter, randomized, double-blind, double-dummy trial depicting the AF occurrence during a 12-month follow-up as the primary end point. A total of 198 patients hospitalized for AFL ablation were enrolled in the trial and randomized to placebo or ramipril 5 mg/day. Patients were followed up during 1 year after AFL ablation using 1-week Holter electrocardiogram at 3, 6, 9, and 12 months. The intention-to-treat population encompassed 97 patients in the ramipril group and 101 patients in the placebo group. The primary end point, such as AF occurrence during the 1-year follow-up, was not different between the 2 groups (p = 0.96). Secondary end points, including the occurrence of supraventricular arrhythmia (p = 0.50), heart failure, stroke, and death, were not different between the 2 groups. Safety outcome parameters, including serious adverse events leading to treatment disruption (p = 0.10), hypotension, impairment of renal function, and elevated serum potassium level, also were not different between the 2 groups. In conclusion, RAAS inhibition using ramipril does not reduce AF occurrence in patients facing AFL ablation during the 1-year follow-up.

Extended Anticoagulant Treatment with Full- or Reduced-Dose Apixaban in Patients with Cancer-Associated Venous Thromboembolism: Rationale and Design of the API-CAT Study.

Cancer-associated thrombosis (CT) is associated with a high risk of recurrent venous thromboembolic (VTE) events that require extended anticoagulation in patients with active cancer, putting them at risk of bleeding. The aim of the API-CAT study (NCT03692065) is to assess whether a reduced-dose regimen of apixaban (2.5 mg twice daily [bid]) is noninferior to a full-dose regimen of apixaban (5 mg bid) for the prevention of recurrent VTE in patients with active cancer who have completed ≥6 months of anticoagulant therapy for a documented index event of proximal deep-vein thrombosis and/or pulmonary embolism. API-CAT is an international, randomized, parallel-group, double-blind, noninferiority trial with blinded adjudication of outcome events. Consecutive patients are randomized to receive apixaban 2.5 or 5 mg bid for 12 months. The primary efficacy outcome is a composite of recurrent symptomatic or incidental VTE during the treatment period. The principal safety endpoint is clinically relevant bleeding, defined as a composite of major bleeding or nonmajor clinically relevant bleeding. Assuming a 12-month incidence of the primary outcome of 4% with apixaban and an upper limit of the two-sided 95% confidence interval of the hazard ratio <2.0, 1,722 patients will be randomized, assuming an up to 10% loss in total patient-years (ß = 80%; α one-sided = 0.025). This trial has the potential to demonstrate that a regimen of extended treatment for patients with CT beyond an initial 6 months, with a reduced apixaban dose, has an acceptable risk of recurrent VTE recurrence and decreases the risk of bleeding.

Failure of the Ottawa Score to Predict the Risk of Recurrent Venous Thromboembolism in Cancer Patients: The Prospective PREDICARE Cohort Study.

INTRODUCTION: Recurrent venous thromboembolism (VTE) despite curative anticoagulation is frequent in patients with cancer. Identifying patients with a high risk of recurrence could have therapeutic implications. A prospective study was designed to validate the Ottawa risk score of recurrent VTE in cancer patients. METHODS: In a prospective multicenter observational cohort, adult cancer patients with a recent diagnosis of symptomatic or incidental lower limb deep vein thrombosis or pulmonary embolism (PE) were treated with tinzaparin for 6 months. The primary endpoint was the recurrence of symptomatic or asymptomatic VTE within the first 6 months of treatment. All clinical events were centrally reviewed and adjudicated. Time-to-event outcomes were estimated by the Kalbfleisch and Prentice method to take into account the competing risk of death. A C-statistic value of > 0.70 was needed to validate the Ottawa score. RESULTS: A total of 409 patients were included and analyzed on an intention-to-treat basis. Median age was 68 years, 60.4% of patients had PE, and VTE was symptomatic in 271 patients (66.3%). The main primary sites were lung (31.3%), lower digestive tract (14.4%), and breast (13.9%) cancers. The Ottawa score was high (≥ 1) in 58% of patients. The 6-month cumulative incidence of recurrent VTE was 7.3% (95% confidence interval [CI]: 4.9-11.1) overall, and 5.0% (95% CI: 2.3-10.8) versus 9.1% (95%CI: 6.1-13.6) in the Ottawa low versus high risk groups, respectively. The C-statistic value was 0.60 (95% CI: 0.55-0.65). CONCLUSION: In this prospective cohort of patients with cancer receiving tinzaparin for VTE, the Ottawa score failed to accurately predict recurrent VTE.