Reproducibility of clinical events adjudications in a trial of venous thromboembolism prevention

Extending venous thromboembolism secondary prevention with apixaban in cancer patients. The EVE trial

BACKGROUND

Cancer-associated venous thromboembolism (VTE) management guideline recommendations include continued therapeutic anticoagulation while active cancer persists. The Federal Drug Administration label for apixaban for secondary VTE prevention includes a dose reduction to 2.5 mg twice daily after 6 months of treatment.

OBJECTIVES

The study's purpose was to determine whether this dose reduction is advisable for cancer-associated VTE.

METHODS

A randomized, double-blind trial compared apixaban 2.5 mg with 5 mg twice daily for 12 months among cancer patients with VTE who had completed 6 to 12 months of anticoagulation therapy. The primary outcome was combined major bleeding plus clinically relevant nonmajor bleeding.

RESULTS

Of 370 patients recruited, 360 were included in the intention-to-treat analyses. Major plus clinically relevant nonmajor bleeding occurred in 16 of 179 patients (8.9%) in the apixaban 2.5 mg group compared with 22 of 181 patients (12.2%) in the 5 mg group (hazard ratio [HR], 0.72; 95% CI, 0.38-1.37; P = .39). Major bleeding occurred in 2.8% of the apixaban 2.5 mg group and in 2.2% of the 5 mg group (HR, 1.26; 95% CI, 0.34-4.66; P = .73). Recurrent VTE or arterial thrombosis occurred in 9 of 179 patients (5.0%) in the apixaban 2.5 mg group and 9 of 181 patients (5.0%) in the 5 mg group (HR, 1.0; 95% CI, 0.40-2.53; P = 1.00). All-cause mortality rates were similar between groups, 13% vs 12% (HR, 1.14; 95% CI, 0.63-2.04; P = .67).

CONCLUSION

For secondary prevention of cancer-associated VTE, apixaban 2.5 mg compared with 5 mg twice daily did not lower combined bleeding events (EVE trial NCT03080883).

Clinical characteristics, time course, and outcomes of major bleeding according to bleeding site in patients with venous thromboembolism

BACKGROUND

Bleeding is the most dreaded complication of anticoagulant therapy for acute venous thromboembolism (VTE). Limited data exist about patient characteristics, time course and outcomes of major bleeding, according to the bleeding site.

METHODS

We used the data from the Registro Informatizado Enfermedad TromboEmbólica (RIETE) registry (03/2001-07/2018) and identified patients who suffered from major bleeding during anticoagulation. We assessed patient characteristics, time course, and 30-day outcomes including mortality, re-bleeding, and VTE recurrences, according to bleeding site.

RESULTS

Among 78,136 patients with VTE receiving anticoagulation, 2244 (2.9%) suffered from major bleeding (gastrointestinal in 800, intracranial in 417, hematoma in 410, genitourinary in 222, retroperitoneal in 145; other sites in 250). There were variations in baseline characteristics, including older age (P < 0.001) and predominance of women (70.2% [95% confidence interval [CI]]: 65.6-74.6% versus 50.5%, 95% CI: 48.2-52.9, P < 0.001) in patients with hematoma, compared with other patients. Overall, 82.7% of hematomas and 81.4% of retroperitoneal bleeds occurred in the first 90 days after the diagnosis of the VTE event, compared with only 50.6% of intracranial bleeds. Across the bleeding subgroups, 30-day all-cause mortality rates were highest in patients who suffered from intracranial bleeding (41.0%; 99% confidence interval [CI]: 34.8-47.4%), and lowest in patients who suffered from hematoma (17.8%; 99% CI: 13.2-23.2%). Patients who suffered from a major bleeding event in the first 30 days after VTE had significantly higher odds at 90-day follow-up to develop mortality (including from bleeding), recurrent VTE, and recurrent major bleeding (all Ps < 0.001). Variations were observed in the results according to the bleeding site.

CONCLUSIONS

Major bleeding is a serious complication in VTE patients. Patient characteristics, time course and outcomes varied substantially according to the bleeding site. Additional studies are needed to tease out the impact of patient risk factors, treatment regimens, and a potential distinct effect from the site of bleeding.

TRIAL REGISTRATION

https://clinicaltrials.gov/ct2/show/NCT02832245 (RIETE registry).

Acute Management of High-Risk and Intermediate-Risk Pulmonary Embolism in Children: A Review

Severe forms of pulmonary embolism (PE) in children, althought rare, cause significant morbidity and mortality. We review the pathophysiologic features of severe (high-risk and intermediate-risk) PE and suggest novel pediatric-specific risk stratifications and an acute treatment algorithm to expedite emergent decision-making. We defined pediatric high-risk PE as causing cardiopulmonary arrest, sustained hypotension, or normotension with signs or symptoms of shock. Rapid primary reperfusion should be pursued with either surgical embolectomy or systemic thrombolysis in conjunction with a heparin infusion and supportive care as appropriate. We defined pediatric intermediate-risk PE as a lack of systemic hypotension or compensated shock, but with evidence of right ventricular strain by imaging, myocardial necrosis by elevated cardiac troponin levels, or both. The decision to pursue primary reperfusion in this group is complex and should be reserved for patients with more severe disease; anticoagulation alone also may be appropriate in these patients. If primary reperfusion is pursued, catheter-based therapies may be beneficial. Acute management of severe PE in children may include systemic thrombolysis, surgical embolectomy, catheter-based therapies, or anticoagulation alone and may depend on patient and institutional factors. Pediatric emergency and intensive care physicians should be familiar with the risks and benefits of each therapy to expedite care. PE response teams also may have added benefit in streamlining care during these critical events.

Safety and Efficiency of Diagnostic Strategies for Ruling Out Pulmonary Embolism in Clinically Relevant Patient Subgroups : A Systematic Review and Individual-Patient Data Meta-analysis

BACKGROUND

How diagnostic strategies for suspected pulmonary embolism (PE) perform in relevant patient subgroups defined by sex, age, cancer, and previous venous thromboembolism (VTE) is unknown.

PURPOSE

To evaluate the safety and efficiency of the Wells and revised Geneva scores combined with fixed and adapted D-dimer thresholds, as well as the YEARS algorithm, for ruling out acute PE in these subgroups.

DATA SOURCES

MEDLINE from 1 January 1995 until 1 January 2021.

STUDY SELECTION

16 studies assessing at least 1 diagnostic strategy.

DATA EXTRACTION

Individual-patient data from 20 553 patients.

DATA SYNTHESIS

Safety was defined as the diagnostic failure rate (the predicted 3-month VTE incidence after exclusion of PE without imaging at baseline). Efficiency was defined as the proportion of individuals classified by the strategy as "PE considered excluded" without imaging tests. Across all strategies, efficiency was highest in patients younger than 40 years (47% to 68%) and lowest in patients aged 80 years or older (6.0% to 23%) or patients with cancer (9.6% to 26%). However, efficiency improved considerably in these subgroups when pretest probability-dependent D-dimer thresholds were applied. Predicted failure rates were highest for strategies with adapted D-dimer thresholds, with failure rates varying between 2% and 4% in the predefined patient subgroups.

LIMITATIONS

Between-study differences in scoring predictor items and D-dimer assays, as well as the presence of differential verification bias, in particular for classifying fatal events and subsegmental PE cases, all of which may have led to an overestimation of the predicted failure rates of adapted D-dimer thresholds.

CONCLUSION

Overall, all strategies showed acceptable safety, with pretest probability-dependent D-dimer thresholds having not only the highest efficiency but also the highest predicted failure rate. From an efficiency perspective, this individual-patient data meta-analysis supports application of adapted D-dimer thresholds.

PRIMARY FUNDING SOURCE

Dutch Research Council. (PROSPERO: CRD42018089366).

ISTH definition of pulmonary embolism-related death and classification of the cause of death in venous thromboembolism studies: Validation in an autopsy cohort

BACKGROUND

The International Society on Thrombosis and Haemostasis (ISTH)'s Scientific and Standardization Committee (SSC) recently proposed a definition of pulmonary embolism (PE)-related death.

OBJECTIVES

To evaluate the accuracy and interrater reliability of the ISTH definition of PE-related death in an autopsy cohort.

METHODS

We reviewed reports of 1064 consecutive adult autopsies that were performed at the NewYork-Presbyterian Hospital from January 2010 until July 2019. We included all patients with autopsy-confirmed PE-related death (cases) during that time frame, combined with patients who died in 2018 from a cause other than PE (controls). Based on clinical summaries, two adjudicators independently adjudicated the cause of death in each patient using the ISTH classification for the cause of death, blinded to the case/control status and ratio. The primary outcome was autopsy-confirmed PE-related death. We determined the sensitivity and specificity of the ISTH definition to identify autopsy-confirmed PE-related death, and its interrater reliability using the percentage agreement and Cohen's kappa.

RESULTS

A total of 126 patients who underwent autopsy were included in the analysis (median age, 68 years [range, 21-94], 60 [48%] women), of which 29 (23%) had died from PE as confirmed by autopsy. The ISTH definition's sensitivity and specificity for autopsy-confirmed PE-related death were 45% (95% CI, 26-64) and 99% (95% CI, 94-100), respectively. Interrater reliability for PE-related death was substantial (percentage agreement, 94% [95% CI, 89-97]; kappa, 0.73 [95% CI, 0.55-0.97]).

CONCLUSION

Adjudication of the cause of death using the ISTH definition resulted in very high specificity, moderate sensitivity, and good interrater reliability for PE-related death.

Thromboembolic risk stratification by TRiP(cast) score to rationalise thromboprophylaxis in patients with lower leg trauma requiring immobilisation: a study protocol of the casting stepped-wedge cluster randomised trial

INTRODUCTION

Patients with lower limb trauma requiring orthopaedic immobilisation may be at risk of venous thromboembolism but opinions differ about who may benefit from thromboprophylactic anticoagulant treatment.The aim of this CASTING study is to demonstrate the safety of thromboprophylaxis based on the Thrombosis Risk Prediction for patients with cast immobilisation (TRiP(cast) score with regards to the 3-month incidence of symptomatic venous thromboembolism events in low-risk patients not receiving thromboprophylaxis, as well as the usefulness of this strategy on the rate of patients receiving anticoagulant treatment in comparison to current practice.

METHODS AND ANALYSIS

CASTING will be a stepped-wedge cluster randomised controlled clinical trial, performed in 15 emergency departments in France and Belgium. With their informed consent, outpatients admitted to one of the participating emergency departments for a lower limb trauma requiring orthopaedic immobilisation without surgery will be included. All centres will begin the trial with the 'observational period' and, every 2 weeks, 1 centre will be randomly assigned to switch to the 'interventional period' and to apply the TRiP(cast) score, in which only patients with a score ≥7 will receive thromboprophylactic anticoagulant treatment. The primary endpoint is the rate of clinical thromboembolic events within 90 days following the inclusion of low-risk patients not receiving thromboprophylaxis.

ETHICS AND DISSEMINATION

The protocol has been approved by the Comité de Protection des Personnes Sud I (Ethics Review ID-RCB: 2019-A01829-48) for France and the Comité d'éthique hôpital-facultaire Saint Luc (N° B403201941338) for Belgium. It is carried out in accordance with the Declaration of Helsinki and Good Clinical Practice guidelines. The findings of this study will be disseminated in peer-reviewed journals and at scientific conferences.

TRIAL REGISTRATION NUMBER

NCT04064489.

Protocol for a scoping review of outcomes in clinical studies of interventions for venous thromboembolism in adults

INTRODUCTION

Venous thromboembolism (VTE) is a common, potentially fatal yet treatable disease. Several advances in treatment of VTE have been made over the past decades, but definition and reporting of outcomes across those studies are inconsistent. Development of an international core outcome set for clinical studies of interventions for VTE addresses this lack of standardisation. The first step in the development of a core outcome set is to conduct a scoping review which aims to generate an inclusive list of unique outcomes that have been reported in previous studies.

METHODS AND ANALYSIS

MEDLINE, Embase and the Cochrane Central Register of Controlled Trials will be searched with no language restriction for prospective studies reporting on interventions for treatment of VTE in patients who are adult and non-pregnant. Records will be sorted in reverse chronological order. Study screening and data extraction will be independently performed by two authors in blocks based on date of publication, starting with 2015 to 2020 and subsequent 1-year periods, until no new outcome measures are identified from the set of included studies. After homogenising spelling and combining outcomes with the same meaning, a list of unique outcomes will be determined. Those outcomes will be grouped into outcome domains. Qualitative analysis and descriptive statistics will be used to report results.

ETHICS AND DISSEMINATION

Ethical approval is not required for this study. The results of this scoping review will be presented at scientific conferences, published in a peer-reviewed journal, and they will provide candidate outcome domains to be considered in subsequent steps in the development of a core outcome set for clinical studies of interventions for VTE. PROTOCOL REGISTRATION DETAILS: http://hdl.handle.net/10393/40459.

Mortality risk associated with venous thromboembolism: a systematic review and Bayesian meta-analysis

BACKGROUND

Venous thromboembolism is associated with increased mortality risk in some populations, but how frequently it is a direct cause of death is unclear. We used data from venous thromboembolism prevention trials to evaluate the causal effect of venous thromboembolism reduction on mortality.

METHODS

We did a systematic review and meta-analysis of randomised controlled trials (RCTs) evaluating venous thromboembolism prevention. We searched MEDLINE, Embase, PubMed, and Web of Science starting from Jan 1, 1993, to March 19, 2018. We included studies of patients who were at elevated risk of venous thromboembolism and were randomly assigned to either anticoagulant or antiplatelet therapy versus placebo or no treatment. We excluded studies with an active control agent (which might mitigate the lethality of venous thromboembolism) and those for which mortality data were unavailable. We modelled heterogeneity in a Bayesian framework, taking overall mortality as a primary endpoint, and pulmonary embolism, fatal pulmonary embolism, and major bleeding as secondary endpoints. We focused our analyses on studies reporting statistically significant effects of prevention on venous thromboembolism endpoints. We report treatment effects as median risk ratios (RRs), wherein a null effect equals 1, with 95% credible intervals (CrIs). This meta-analysis was registered with PROSPERO, CRD42018089697.

FINDINGS

From 4229 studies screened, we identified 86 eligible RCTs; 52, with data from over 70 000 patients, were positive, with significantly increased venous thromboembolism risk in patients in control groups versus treatment groups (RR 2·74, 95% CrI 2·32-3·31, p<0·0001). The meta-analysis established that the causal effect of venous thromboembolism prevention on mortality was null (control group mortality was 3391 [9·8%] of 34 537 patients; treatment group mortality was 3498 [9·8%] of 35 795 patients [RR 1·01, 95% CrI 0·97-1·06; p=0·58]) with low heterogeneity (τ 0·02, 95% CrI 0·00-0·07, p=0·89). Patients in control groups had more pulmonary embolism (RR 2·22, 95% CrI 1·78-2·89, p<0·0001) and fatal pulmonary embolism (1·58, 1·14-2·19, p=0·01), but less major bleeding (0·60, 0·47-0·75, p<0·0001) than those in treatment groups. A meta-analysis with the additional 34 negative studies yielded similar results for all endpoints except fatal pulmonary embolism, where evidence of an effect was weaker (1·42, 1·05-1·91, p=0·02).

INTERPRETATION

The perception that venous thromboembolism is a common cause of mortality should be revised considering the null effect of venous thromboembolism prevention on mortality. Our findings call into question the use of composite endpoints in venous thromboembolism-prevention trials and provide rationale for de-escalation trials.

FUNDING

None.

Comparison of Outcome Adjudication by Investigators and by a Central End Point Committee in Heart Failure Trials

Background:

The usefulness of adjudication by central end point committees (CECs) is poorly assessed in heart failure (HF) trials. We aimed to assess its impact on the outcome of the SHIFT trial (Systolic HF Treatment With the If Inhibitor Ivabradine Trial).

Methods:

SHIFT was a randomized placebo-controlled trial investigating the effect of ivabradine in 6505 HF patients with reduced ejection fraction. Prespecified end points, reported by investigators (all cardiologists) using specific case report form pages, included all-cause and specific causes of deaths and hospitalizations. The primary end point was a composite of cardiovascular deaths or hospitalizations for worsening HF. We compared the adjudication of prespecified end points made by investigators and by the CEC.

Results:

Investigators identified 7529 prespecified end points, 6793 of which were confirmed by the CEC: 98.1% of cardiovascular deaths, 88.6% of all hospitalizations, and 84.4% of hospitalizations for worsening HF. These differences had no meaningful impact on the study results; hazard ratio for the primary composite end point: investigators, 0.83 (95% CI, 0.76–0.91) versus CEC, 0.82 (95% CI, 0.75–0.90), with similar results for each component of the primary end point (hazard ratio of 0.92 versus 0.91 for cardiovascular death and 0.78 versus 0.74 for hospitalization for worsening HF).

Conclusions:

Central adjudication by a CEC in the SHIFT study confirmed most of cardiovascular deaths and worsening HF hospitalizations assessed by cardiologists and did not result in a significant change of the final result as compared to investigator judgment. In this context, the benefits of CEC in blinded HF trials should be reconsidered.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02441218. URL: http://www.isrctn.com/ISRCTN70429960 ; Unique identifier: ISRCTN70429960.

Adverse Events and Mortality in Anticoagulated Patients with Different Categories of Pulmonary Embolism

Objective

To determine whether the pulmonary embolism (PE) categories of massive, submassive, PE with no right ventricle dysfunction (NRVD), and subsegmental only (SSO) adequately predict clinical outcome.

Methods

Patients treated for acute PE (March 1, 2013, through July 31, 2019) were followed forward prospectively to compare venous thromboembolism (VTE) recurrence, all-cause mortality, major bleeding, and clinically relevant nonmajor bleeding (CRNMB) across 4 PE categories.

Results

Of 2703 patients with VTE, 1188 (44%) had PE, of which 1021 (85.9%) completed at least 3 months of therapy or had clinical outcomes precluding further treatment (27 with massive, 217 submassive, 557 NRVD, and 220 SSO PE). One patient with massive, 8 with submassive, 23 with NRVD, and 5 with SSO PE had recurrent VTE (3.90, 5.33, 5.36, and 3.66 per 100 person-years, respectively; P=.84). There were 3 deaths in massive, 27 in submassive, 140 in NRVD, and 34 in SSO PE groups (11.59, 17.37, 31.74, and 24.74 per 100 person-years, respectively; P=.02); when adjusted for cancer, the relationship was no longer significant (P=.27). One patient with massive, 5 with submassive, 22 with NRVD, and 5 with SSO PE had major bleeding (3.90, 3.31, 5.24, and 3.75 per 100 person-years, respectively; P=.66). Similar cumulative rates for CRNMB were observed (P=.87). Three-month rates of VTE recurrence, death, major bleeding, and CRNMB did not differ by PE category.

Conclusion

In the setting of anticoagulation therapy with maximal standardization and evidence-based practice, there is no evidence of a difference between PE categories and outcomes.

Trial Registration

clinicaltrials.gov Identifier: NCT03504007.

Risk Stratification of Pulmonary Embolism

Given the broad treatment options, risk stratification of pulmonary embolism is a highly desirable component of management. The ideal tool identifies patients at risk of death from the original or recurrent pulmonary embolism. Using all-cause death in the first 30-days after pulmonary embolism diagnosis as a surrogate, clinical parameters, biomarkers, and radiologic evidence of right ventricular dysfunction and strain are predictive. However, no study has demonstrated improved mortality rates after implementation of a risk stratification strategy to guide treatment. Further research should use better methodology to study prognosis and test new management strategies in patients at high risk for death.

Definition of pulmonary embolism-related death and classification of the cause of death in venous thromboembolism studies: Communication from the SSC of the ISTH

Pulmonary embolism (PE)-related death is often a component of the primary outcome in venous thromboembolism (VTE) clinical studies. Definitions for PE-related death vary widely, which may lead to biased risk estimates of clinical outcomes, thereby affecting both internal and external validity of study results. We here provide a standardized definition of PE-related death and propose guidance for classification and reporting of the cause of death for clinical studies in VTE. The proposal was developed in a four-step process, including a systematic review of definitions used for PE-related death in previous studies, two subsequent surveys with VTE experts, and meetings held within the Scientific and Standardization Committee (SSC) working group until consensus on the proposal was reached. The proposed classification comprises three categories: Category A: PE-related death, category B: undetermined cause of death, and category C: cause of death other than PE. Category A includes A1: autopsy-confirmed PE in the absence of another more likely cause of death; A2: objectively confirmed PE before death in the absence of another more likely cause of death; and A3: PE is not objectively confirmed, but is most likely the main cause of death. Category B includes B1: cause of death is undetermined, despite available information; and B2: insufficient clinical information available to determine the cause of death. The use of the proposed definition will hopefully improve the accuracy of study outcomes, between-study comparisons, meta-analyses, and validity of future clinical VTE studies.

Validation of risk assessment models predicting venous thromboembolism in acutely ill medical inpatients: A cohort study

BACKGROUND

Because hospital-acquired venous thromboembolism (VTE) represents a frequent cause of preventable deaths in medical inpatients, identifying at-risk patients requiring thromboprophylaxis is critical. We aimed to externally assess the Caprini, IMPROVE, and Padua VTE risk scores and to compare their performance to advanced age as a stand-alone predictor.

METHODS

We performed a retrospective analysis of patients prospectively enrolled in the PREVENU trial. Patients aged 40 years and older, hospitalized for at least 2 days on a medical ward were consecutively enrolled and followed for 3 months. Critical ill patients were not recruited. Patients diagnosed with VTE within 48 hours from admission, or receiving full dose anticoagulant treatment or who underwent surgery were excluded. All suspected VTE and deaths occurring during the 3-month follow-up were adjudicated by an independent committee. The three scores were retrospectively assessed. Body mass index, needed for the Padua and Caprini scores, was missing in 44% of patients.

RESULTS

Among 14 910 eligible patients, 14 660 were evaluable, of which 1.8% experienced symptomatic VTE or sudden unexplained death during the 3-month follow-up. The area under the receiver operating characteristic curves (AUC) were 0.60 (95% confidence interval [CI] 0.57-0.63), 0.63 (95% CI 0.60-0.66) and 0.64 (95% CI 0.61-0.67) for Caprini, IMPROVE, and Padua scores, respectively. None of these scores performed significantly better than advanced age as a single predictor (AUC 0.61, 95% CI 0.58-0.64).

CONCLUSION

In our study, Caprini, IMPROVE, and Padua VTE risk scores have poor discriminative ability to identify not critically ill medical inpatients at risk of VTE, and do not perform better than a risk evaluation based on patient's age alone.

Extending venous thromboembolism secondary prevention with apixaban in cancer patients: The EVE trial

BACKGROUND

Cancer-associated venous thromboembolism (VTE) carries a high rate of recurrence and death. Guidelines recommend continued anticoagulation therapy as long as active cancer persists. Apixaban 2.5 mg twice daily is the FDA-approved dose for secondary prevention regardless of VTE causation. Whether this apixaban dose is appropriate for secondary VTE prevention in cancer patients is not clear. The rationale and design of this investigator initiated phase III, multicenter, randomized, double-blind, trial assessing apixaban 2.5 mg vs 5 mg twice daily for 12 months for the secondary VTE prevention in cancer patients (n = 370) who have completed 6 months (but no more than 12 months) of anticoagulation is provided (NCT03080883).

METHODS/DESIGN

The primary study objective is to estimate differences in the combined rate of major plus clinically relevant non-major bleeding for apixaban 2.5 mg vs 5 mg twice daily. Secondary efficacy outcome is to assess rates of venous or arterial thromboembolism. Participating centers are chosen from the Academic and Community Cancer Research United (ACCRU) consortium.

CONCLUSION

We anticipate these trial results to provide evidence supporting low-dose apixaban as a safe agent for secondary prevention of cancer-associated VTE for patients who have already completed 6-12 months of anticoagulation.

Comparison of apixaban to rivaroxaban and enoxaparin in acute cancer-associated venous thromboembolism

To provide direct comparison between apixaban and rivaroxaban in patients with acute cancer-associated venous thromboembolism (Ca-VTE), consecutive patients treated with apixaban, rivaroxaban, or enoxaparin at Mayo Thrombophilia Clinic (March 1, 2013 to January 31, 2018)) were followed prospectively. The primary effectiveness outcome was venous thromboembolism (VTE) recurrence, and the secondary was mortality. The primary safety outcome was major bleeding, the secondary clinically relevant safety outcome was non-major bleeding (CRNMB), and the third a composite of major and CRNMB. There were 750 patients treated for acute Ca-VTE with apixaban (n = 224), rivaroxaban (n = 163), and enoxaparin (n = 363) within 14 days of diagnosis and for at least 3 months, or until study event. Recurrent VTE was diagnosed in 11 receiving apixaban, 7 receiving rivaroxaban (apixaban vs rivaroxaban hazard ratio (HR) 1.31, 95% confidence interval (95% CI) 0.51-3.36) and 17 in the enoxaparin receiving group (apixaban vs enoxaparin HR 1.14, 95% CI: 0.54, 2.42 and rivaroxaban vs enoxaparin HR 0.85, 95% Cl: 0.36, 2.06). There were 82 deaths in apixaban, 74 rivaroxaban (apixaban vs rivaroxaban HR 1.67, 95% Cl: 1.20, 2.33) and 171 in enoxaparin group (rivaroxaban vs enoxaparin HR 0.73, 95% Cl: 0.56, 0.96). Major bleeding occurred in 11 apixaban, 12 rivaroxaban (apixaban vs rivaroxaban HR 0.73, 95% Cl: 0.32, 1.66) and 21 enoxaparin group (apixaban vs enoxaparin HR 0.89, 95% Cl: 0.43, 1.84 and rivaroxaban vs enoxaparin HR 1.23, 95% Cl: 0.61, 2.50). The CRNMB rate was higher in rivaroxaban compared to apixaban (P = .03) and LMWH (P = .01) groups. Recurrence of VTE and major bleeding were similar in apixaban, rivaroxaban, and enoxaparin groups. Rivaroxaban was associated with higher CRNMB but lower mortality compared to apixaban and enoxaparin.

Definitions, adjudication, and reporting of pulmonary embolism-related death in clinical studies: A systematic review

BACKGROUND

Pulmonary embolism (PE)-related death is a component of the primary outcome in many venous thromboembolism (VTE) studies. The absence of a standardized definition for PE-related death hampers study outcome evaluation and between-study comparisons.

OBJECTIVES

To summarize definitions for PE-related death used in recent VTE studies and to assess the PE-related death rate.

PATIENTS/METHODS

A systematic literature search was conducted on 26 April 2018 from 1 January 2014 up to the search date in MEDLINE, Embase, and CENTRAL. Cohort studies and randomized trials in which PE-related death was included in the primary outcome were eligible. Screening of titles, abstracts, and full-text articles, and data extraction were independently performed in duplicate by two authors. Study outcomes included the definition for PE-related death, VTE case-fatality rate, and death due to PE rate. Descriptive statistics were used to analyze the data.

RESULTS

Of the 6807 identified citations, 83 studies were included of which 27% were randomized trials, 31% were prospective, and 42% retrospective cohort studies. Thirty-five studies (42%) had a central adjudication committee. Thirty-eight (46%) reported a definition for PE-related death of which the most frequently used components were "autopsy-confirmed PE" (50%), "objectively confirmed PE before death" (55%), and "unexplained death" (58%). Median VTE case-fatality rate was 1.8% (interquartile range, 0.0-13).

CONCLUSIONS

Only half of the included studies reported definitions for PE-related death, which were very heterogeneous. Case-fatality rate of VTE events varied widely across studies. Standardization of the definition and guidance on adjudication and reporting of PE-related death is needed.

Assessment of the End Point Adjudication Process on the Results of the Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke (POINT) Trial: A Secondary Analysis

IMPORTANCE

Debate continues about the value of event adjudication in clinical trials and whether independent centralized assessments improve reliability and validity of study results in masked randomized trials compared with local, investigator-assessed end points.

OBJECTIVE

To assess the results of the adjudicated end point process in the Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke (POINT) trial by comparing end points assessed by local site investigators with centrally adjudicated end points.

DESIGN, SETTING, AND PARTICIPANTS

This is an ad hoc secondary analysis of a randomized, double-blind clinical trial comparing safety and effectiveness of clopidogrel bisulphate plus aspirin vs placebo plus aspirin. Patients received either 600 mg of clopidogrel bisulphate on day 1, then 75 mg per day through day 90 plus 50 to 325 mg of aspirin per day, or the same range of dosages of placebo plus aspirin. Investigators reported all potential end points; independent masked adjudicators were randomly assigned to review using definitions specified in the study protocol. This was a multicenter study; 269 international sites in 10 countries enrolled from May 28, 2010, to December 19, 2017. The study enrolled 4881 patients 18 years or older with transient ischemic attack or minor acute ischemic stroke within 12 hours of symptom onset and followed for 90 days from randomization; last follow-up was completed in March 2018.

MAIN OUTCOMES AND MEASURES

Independent adjudicators external to the study and masked to study treatment assignment adjudicated 467 primary and secondary effectiveness outcomes and major and minor bleeding events, including the primary composite end point, which was the risk of a composite of major ischemic events at 90 days, defined as ischemic stroke, myocardial infarction, or death from an ischemic vascular event. The primary safety end point was major hemorrhage. All components of the primary and safety outcomes were adjudicated.

RESULTS

In this secondary analysis of an international randomized clinical trial, a total of 269 sites worldwide randomized 4881 patients (median age, 65.0 years; interquartile range, 55-74 years); 55.0% were male. The primary results have been published previously. The hazard ratios for clopidogrel plus aspirin vs placebo plus aspirin for the primary composite end point were 0.75 (95% CI, 0.59-0.95) for adjudicator-assessed events and 0.76 (95% CI, 0.60-0.95) for investigator-assessed events. Agreement between adjudicator and investigator assessments was 90.7%. The hazard ratios for clopidogrel plus aspirin vs placebo plus aspirin for the primary safety end point were 2.32 (95% CI, 1.10-4.87) for adjudicator-assessed events and 2.58 (95% CI, 1.19-5.58) for investigator-assessed events, with an agreement rate of 77.5%.

CONCLUSIONS AND RELEVANCE

Independent end point adjudication did not substantially alter estimates of the primary treatment effectiveness in the POINT trial.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00991029.

Apixaban and Rivaroxaban in Patients With Acute Venous Thromboembolism

OBJECTIVE

To compare the clinical efficacy and safety of apixaban with those of rivaroxaban for the treatment of acute venous thromboembolism (VTE).

PATIENTS AND METHODS

Consecutive patients enrolled in the Mayo Thrombophilia Clinic Registry (between March 1, 2013, and January 30, 2018) and treated with apixaban or rivaroxaban for acute VTE were followed forward in time. The primary efficacy outcome was VTE recurrence. The primary safety outcome was major bleeding; the second safety outcome was clinically relevant nonmajor bleeding (CRNMB); and the third was a composite of major bleeding or CRNMB.

RESULTS

Within the group of 1696 patients with VTE enrolled, 600 (38%) were treated either with apixaban (n=302, 50%) or rivaroxaban (n=298, 50%) within the first 14 days of VTE diagnosis and who completed at least 3 months of therapy or had a study event. Recurrent VTE was diagnosed in 7 patients (2.3%) treated with apixaban and in 6 (2%) treated with rivaroxaban (adjusted hazard ratio [aHR], 1.4; 95% CI, 0.5-3.8). Major bleeding occurred in 11 patients (3.6%) receiving apixaban and in 9 patients (3.0%) receiving rivaroxaban (aHR, 1.2; 95% CI, 0.5-3.2). Clinically relevant nonmajor bleeding was diagnosed in 7 patients (2.3%) receiving apixaban and in 20 (6.7%) receiving rivaroxaban (aHR, 0.4; 95% CI, 0.2-0.9). The rates of composite major bleeding or CRNMB were similar (aHR, 0.6; 95% CI, 0.3-1.2). Most study events occurred in patients with cancer.

CONCLUSION

In the setting of a standardized, guideline-directed, patient-oriented clinical practice, the efficacy and safety of apixaban and rivaroxaban for the treatment of acute VTE were comparable.

Fatal recurrent VTE after anticoagulant treatment for unprovoked VTE: a systematic review

Current guidelines recommend long-term anticoagulant therapy in patients with unprovoked venous thromboembolism (VTE). The risk of fatal recurrent VTE after treatment discontinuation (versus that of fatal bleeding during anticoagulation) is of particular relevance in the decision to continue or stop anticoagulation after the first 3 months. Our primary aim was to provide a point-estimate of the yearly rate of fatal recurrent VTE and VTE case-fatality rate in patients with unprovoked VTE after anticoagulation cessation. Data were extracted from both randomised controlled trials and observational studies published before May 1, 2017. The pooled fatality rates were calculated using a random-effects model. 18 studies with low-to-moderate bias were included in the primary analysis, totalling 6758 patients with a median (range) follow-up duration of 2.2 (1–5) years. After anticoagulation cessation, the weighted pooled rate of VTE recurrence was 6.3 (95% CI 5.4–7.3) per 100 patient-years and the weighted pooled rate of fatal recurrent VTE was 0.17 (95% CI 0.047–0.33) per 100 patient-years, for a case-fatality rate of 2.6% (95% CI 0.86–5.0). These numbers are a solid benchmark for comparison to the risks associated with long-term anticoagulation treatment for the decision on the optimal duration of treatment of patients with unprovoked VTE.

Pulmonary embolism rule-out criteria (PERC) rule in European patients with low implicit clinical probability (PERCEPIC): a multicentre, prospective, observational study

BACKGROUND

The ability of the pulmonary embolism rule-out criteria (PERC) to exclude pulmonary embolism without further testing remains debated outside the USA, especially in the population with suspected pulmonary embolism who have a high prevalence of the condition. Our main objective was to prospectively assess the predictive value of negative PERC to rule out pulmonary embolism among European patients with low implicit clinical probability.

METHODS

We did a multicentre, prospective, observational study in 12 emergency departments in France and Belgium. We included consecutive patients aged 18 years or older with suspected pulmonary embolism. Patients were excluded if they had already been hospitalised for more than 2 days, had curative anticoagulant therapy in progress for more than 48 h, or had a diagnosis of thromboembolic disease documented before admission to emergency department. Physicians completed a standardised case report form comprising implicit clinical probability assessment (low, moderate, or high) and a list of risk factors including criteria of the PERC rule. They were asked to follow international recommendations for diagnostic strategy, masked to PERC assessment. The primary endpoint was the proportion of patients with low implicit clinical probability and negative PERC who had venous thromboembolic events, diagnosed during initial diagnostic work-up or during 3-month follow-up, as externally adjudicated by an independent committee masked to the PERC and clinical probability assessment. The upper limit of the 95% CI around the 3-month thromboembolic risk was set at 3%. We did all analyses by intention to treat, including all patients with complete follow-up. This trial is registered with ClinicalTrials.gov, number NCT02360540.

FINDINGS

Between May 1, 2015, and April 30, 2016, 1773 consecutive patients with suspected pulmonary embolism were prospectively assessed for inclusion, of whom 1757 were included. 1052 (60%) patients were classed as having low clinical probability, 49 (4·7%, 95% CI 3·5-6·1) of whom had a venous thromboembolic event. In patients with a low implicit clinical probability, 337 (32%) patients had negative PERC, of whom four (1·2%; 95% CI 0·4-2·9) went on to have a pulmonary embolism.

INTERPRETATION

In European patients with low implicit clinical probability, PERC can exclude pulmonary embolism with a low percentage of false-negative results. The results of our prospective, observational study allow and justify an implementation study of the PERC rule in Europe.

FUNDING

French Ministry of Health.