Characterization of cardiovascular clinical events and impact of event adjudication on the treatment effect of darapladib versus placebo in patients with stable coronary heart disease: Insights from the STABILITY trial

Adjudication of Self-reported Symptomatic Stone Recurrence in the Prevention of Urinary Stones With Hydration Trial

OBJECTIVE

To assess accuracy of self-reported stone events in a large clinical trial by adjudication against the weight of documentation for spontaneous stone passage or surgical intervention.

METHODS

Participants in the Prevention of Urinary Stones with Hydration (PUSH) trial were randomized to a multi-component behavioral intervention or control arm to increase and maintain high fluid intake. The primary endpoint was urinary stone events including symptomatic stone passage or procedural intervention. An independent adjudication committee blinded to randomization assignments reviewed all events. Confirmed clinical stone events required typical stone symptoms and documentation of stone passage (eg, via photograph, clinical record) and/or surgical intervention. Events with typical symptoms and self-described stone passage but without objective documentation of passage were also considered as meeting the primary endpoint and classified separately as patient-reported passage. Non-events did not meet either criteria.

RESULTS

At time of this blinded analysis, a total of 1658 participants were randomized and had a median follow-up of 19 months. Self-reported stone events (n = 217) were adjudicated by the committee as either confirmed clinical events (134; 61.8%), patient-reported passage (71; 32.7%), or non-events (12; 5.5%). Confirmed clinical events consisted of stone passage in 66/134 and procedural interventions in 68/134 (53 for symptoms and 15 without symptoms).

CONCLUSION

Rigorous adjudication revealed that self-reported stone events in the PUSH trial overwhelmingly represented clinically documented passage, surgical intervention, and patient-reported passage outside healthcare settings, with only 5.5% failing to satisfy adjudication criteria. Similar adjudication and classification processes warrant consideration for implementation in future stone trials.

CLINICAL TRIALS REGISTRATION

NCT03244189.

Is Myocardial Infarction Overdiagnosed?

This Viewpoint examines whether overdiagnosis rather than underdiagnosis may now be the dominant form of myocardial infarction misdiagnosis.

Endpoint adjudication in cardiovascular clinical trials

Endpoint adjudication (EA) is a common feature of contemporary randomized controlled trials (RCTs) in cardiovascular medicine. Endpoint adjudication refers to a process wherein a group of expert reviewers, known as the clinical endpoint committee (CEC), verify potential endpoints identified by site investigators. Events that are determined by the CEC to meet pre-specified trial definitions are then utilized for analysis. The rationale behind the use of EA is that it may lessen the potential misclassification of clinical events, thereby reducing statistical noise and bias. However, it has been questioned whether this is universally true, especially given that EA significantly increases the time, effort, and resources required to conduct a trial. Herein, we compare the summary estimates obtained using adjudicated vs. non-adjudicated site designated endpoints in major cardiovascular RCTs in which both were reported. Based on these data, we lay out a framework to determine which trials may warrant EA and where it may be redundant. The value of EA is likely greater when cardiovascular trials have nuanced primary endpoints, endpoint definitions that align poorly with practice, sub-optimal data completeness, greater operator variability, and lack of blinding. EA may not be needed if the primary endpoint is all-cause death or all-cause hospitalization. In contrast, EA is likely merited for more nuanced endpoints such as myocardial infarction, bleeding, worsening heart failure as an outpatient, unstable angina, or transient ischaemic attack. A risk-based approach to adjudication can potentially allow compromise between costs and accuracy. This would involve adjudication of a small proportion of events, with further adjudication done if inconsistencies are detected.

Comparison of Investigator-Reported vs Centrally Adjudicated Major Adverse Cardiac Events: A Secondary Analysis of the COMPASS Trial

IMPORTANCE

In the Cardiovascular Outcomes for People Using Anticoagulation Strategies (COMPASS) trial, there was a significant reduction in the adjudicated primary outcome among patients with stable atherosclerotic vascular disease randomized to dual pathway inhibition (rivaroxaban 2.5 mg twice daily plus aspirin 100 mg daily) vs aspirin monotherapy, but not with rivaroxaban 5 mg twice daily vs aspirin monotherapy. Whether the results are similar without adjudication is unknown.

OBJECTIVE

To examine the impact of dual pathway inhibition (with rivaroxaban plus aspirin) or rivaroxaban monotherapy compared with aspirin monotherapy on investigator-reported CV events and to understand the extent of concordance between investigator-reported and centrally adjudicated clinical events.

DESIGN, SETTING, AND PARTICIPANTS

This is a secondary analysis of the COMPASS trial, an international, double-blind, double-dummy, randomized clinical trial with a 3-by-2 partial factorial design that evaluated participants with stable atherosclerotic vascular disease receiving rivaroxaban plus aspirin, rivaroxaban monotherapy, or aspirin monotherapy. End points were collected by blinded site investigators and adjudicated by a blinded clinical end point committee. Data were analyzed from March 2013 through February 2017.

INTERVENTIONS

Participants received dual inhibition pathway (2.5 mg rivaroxaban twice daily plus 100 mg aspirin once daily), rivaroxaban monotherapy (5 mg twice daily), or aspirin monotherapy (100 mg once daily).

MAIN OUTCOMES AND MEASURES

The primary efficacy outcome was a composite of cardiovascular (CV) death, stroke, or myocardial infarction (MI). Adjudicated and investigator-reported end points were compared.

RESULTS

A total of 27 395 patients (mean [SD] age, 68.2 [7.9] years; 78.0% men) were assessed, including 9152 patients randomized to dual pathway inhibition, 9117 patients randomized to rivaroxaban monotherapy, and 9126 patients randomized to aspirin monotherapy. Adjudication reduced the number of events by 10% to 15% for most end points. Among investigator-reported end points, dual pathway inhibition significantly reduced the rate of the primary efficacy outcome compared with aspirin alone (411 patients [4.5%] vs 542 patients [5.9%]; hazard ratio [HR], 0.75 [95% CI, 0.66-0.85]; P < .001), with similar reduction in adjudicated end points, (379 patients [4.1%] vs 496 patients [5.4%]; HR, 0.76 [95% CI, 0.66-0.86]; P < .001). Likewise, effects on ischemic end points were highly concordant (κ statistic = 0.94 [95% CI, 0.93-0.95] for the primary composite end point). Unlike with adjudicated outcomes, there was a significant reduction in the primary end point with rivaroxaban monotherapy vs aspirin monotherapy using investigator-reported events (477 patients [5.2%] vs 542 patients [5.9%]; HR, 0.88 [95% CI, 0.78-0.99]; P = .04) compared with adjudicated events (448 patients [4.9%] vs 496 patients [5.4%]; HR, 0.90 [95% CI, 0.79-1.03]; P = .12).

CONCLUSIONS AND RELEVANCE

This secondary analysis of the COMPASS trial found that whether assessed by blinded site investigators or adjudicators, dual pathway inhibition significantly reduced CV events among patients with stable atherosclerotic disease compared with aspirin plus placebo. These findings suggest that using investigator-reported events in blinded clinical trials may be a more efficient alternative to adjudication.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01776424.

Has Unstable Angina Become a Vestigial of the Past in Clinical Trial Primary Endpoints?

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Comparative Reductions in Investigator-Reported and Adjudicated Ischemic Events in REDUCE-IT

BACKGROUND

REDUCE-IT (Reduction of Cardiovascular Events With Icosapent Ethyl-Intervention Trial) randomized statin-treated patients with elevated triglycerides to icosapent ethyl (IPE) or placebo. There was a significant reduction in adjudicated events, including the primary endpoint (cardiovascular [CV] death, myocardial infarction [MI], stroke, coronary revascularization, unstable angina requiring hospitalization) and key secondary endpoint (CV death, MI, stroke) with IPE.

OBJECTIVES

The purpose of this study was to determine the effects of IPE on investigator-reported events.

METHODS

Potential endpoints were collected by blinded site investigators and subsequently adjudicated by a blinded Clinical Endpoint Committee (CEC) according to a prespecified charter. Investigator-reported events were compared with adjudicated events for concordance.

RESULTS

There was a high degree of concordance between investigator-reported and adjudicated endpoints. The simple Kappa statistic between CEC-adjudicated vs site-reported events for the primary endpoint was 0.89 and for the key secondary endpoint was 0.90. Based on investigator-reported events in 8,179 randomized patients, IPE significantly reduced the rate of the primary endpoint (19.1% vs 24.6%; HR: 0.74 [95% CI: 0.67-0.81]; P < 0.0001) and the key secondary endpoint (10.5% vs 13.6%; HR: 0.75 [95% CI: 0.66-0.85]; P < 0.0001). Among adjudicated events, IPE similarly reduced the rate of the primary and key secondary endpoints.

CONCLUSIONS

IPE led to consistent, significant reductions in CV events, including MI and coronary revascularization, as determined by independent, blinded CEC adjudication as well as by blinded investigator-reported assessment. These results highlight the robust evidence for the substantial CV benefits of IPE seen in REDUCE-IT and further raise the question of whether adjudication of CV outcome trial endpoints is routinely required in blinded, placebo-controlled trials. (Evaluation of the Effect of AMR101 on Cardiovascular Health and Mortality in Hypertriglyceridemic Patients With Cardiovascular Disease or at High Risk for Cardiovascular Disease: REDUCE-IT [Reduction of Cardiovascular Events With EPA - Intervention Trial]; NCT01492361).

Cardiovascular Safety of Abaloparatide in Postmenopausal Women With Osteoporosis: Analysis From the ACTIVE Phase 3 Trial

CONTEXT

Abaloparatide is a US Food and Drug Administration-approved parathyroid hormone-related peptide analog for treatment of osteoporosis in postmenopausal women at high risk of fracture.

OBJECTIVES

We assessed the cardiovascular safety profile of abaloparatide.

DESIGN

Review of heart rate (HR), blood pressure (BP), and cardiovascular-related adverse events (AEs), including major adverse cardiovascular events (MACEs) and heart failure (HF) from: (a) ACTIVE (NCT01343004), a phase 3 trial that randomized 2463 postmenopausal women with osteoporosis to abaloparatide, teriparatide, or placebo for 18 months; (b) ACTIVExtend (NCT01657162), where participants from the abaloparatide and placebo arms received alendronate for 2 years; and (c) a pharmacology study in 55 healthy adults.

RESULTS

Abaloparatide and teriparatide transiently increased HR relative to placebo. Following first dose, mean (standard deviation [SD]) HR change from pretreatment to 1 hour posttreatment was 7.9 (8.5) beats per minute (bpm) for abaloparatide, 5.3 (7.5) for teriparatide, and 1.2 (7.1) for placebo. A similar pattern was observed over subsequent visits. In healthy volunteers, HR increase resolved within 4 hours. The corresponding change in mean supine systolic and diastolic BP 1 hour posttreatment was -2.7/-3.6 mmHg (abaloparatide), -2.0/-3.6 (teriparatide), and -1.5/-2.3 (placebo). The percentage of participants with serious cardiac AEs was similar among groups (0.9%-1.0%). In a post hoc analysis, time to first incidence of MACE + HF was longer with abaloparatide (P = 0.02 vs placebo) and teriparatide (P = 0.04 vs placebo).

CONCLUSIONS

Abaloparatide was associated with transient increases in HR and small decreases in BP in postmenopausal women with osteoporosis, with no increase in risk of serious cardiac AEs, MACE, or HF.

Methods for safety and endpoint ascertainment: identification of adverse events through scrutiny of negatively adjudicated events

Background

The primary goal of phase 2 and 3 clinical trials is to evaluate the safety and effectiveness of therapeutic interventions, and efficient and reproducible ascertainment of important clinical events, either as clinical outcome events (COEs) or adverse events (AEs), is critical. Clinical outcomes require consistency and clinical judgment, so these events are often adjudicated centrally by clinical events classification (CEC) physician reviewers using standardized definitions. In contrast, AEs are reported by sites to the trial coordinating center based on common reporting criteria set by regulatory authorities and trial sponsors. These different requirements have led to the development of separate tracks for COE and AE review.

Main body

Potential COEs that fail to meet standardized definitions for CEC adjudication – i.e. negatively adjudicated events (NAE) – may meet criteria for AEs. Trial oversight practices require the sponsor to process AEs regardless of how the AEs are submitted; therefore, review of NAEs may be necessary to ensure that important AEs do not go unreported. The Duke Clinical Research Institute (DCRI) developed and implemented a process for scrutinizing NAEs to detect potential missed serious AEs. Initial experience with this process across two trials suggests that approximately 0.2% of NAEs are serious unexpected AEs that were not otherwise reported and another 1.5% are serious expected AEs.

Conclusions

Given their infrequent concealment of serious AEs in two large trials assessing cardiovascular outcomes, routine scrutiny of NAEs to identify AEs is not recommended at this time, though it may be useful in some trials and should be carefully considered by the trial team. Closer integration of data across safety surveillance and endpoint adjudication systems may enable scrutiny of NAEs when indicated while limiting complexity associated with this process.

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.