Portfolio of clinical research in adult cardiovascular disease as reflected in ClinicalTrials.gov

Outcomes among patients with peripheral artery disease in the Aspirin Dosing: A Patient-Centric Trial Assessing Benefits and Long-Term Effectiveness (ADAPTABLE) study

BACKGROUND

We aimed to understand the effects of aspirin dose on outcomes in patients with peripheral artery disease (PAD) as well as their participation in a pragmatic randomized controlled trial.

METHODS

In a subanalysis of the Aspirin Dosing: A Patient-Centric Trial Assessing Benefits and Long-Term Effectiveness (ADAPTABLE) study, we compared aspirin doses (81 vs 325 mg) among participants with PAD and study participation metrics in patients with and without PAD. The primary outcome composite was all-cause mortality, nonfatal myocardial infarction, and nonfatal stroke.

RESULTS

Among 14,662 participants enrolled in ADAPTABLE with PAD status available, 3493 (23.8%) had PAD. Participants with PAD were more likely to experience the primary composite (13.76% vs 5.31%, p < 0.001), all-cause mortality (7.55% vs 3.01%, p < 0.001), myocardial infarction (5.71% vs 2.09%, p < 0.001), stroke (2.45% vs 0.86%, p < 0.001), and major bleeding (1.19% vs 0.44%, p < 0.001). A higher aspirin dose did not reduce the primary outcome in patients with PAD (13.68% vs 13.84% in 81 mg and 325 mg groups; OR 1.05, 95% CI 0.88-1.25). Participants with PAD were less likely to enroll via email (33.0% vs 41.9%, p < 0.0001), less likely to choose internet follow-up (79.2% vs 89.5%, p < 0.0001), and were more likely to change their aspirin doses (39.7% vs 30.7%, p < 0.0001).

CONCLUSIONS

ADAPTABLE participants with PAD did not benefit from a higher dose of aspirin and participated in the study differently from those without PAD. These results reinforce the need for additional PAD-specific research and suggest that different trial strategies may be needed for optimal engagement of patients with PAD. (ClinicalTrials.gov Identifier: NCT02697916).

Study design, result posting and publication of late-stage cardiovascular trials

AIMS

Pre-registration of study protocols in accessible databases is required for publication of study results in high-impact medical journals. Nonetheless, data on characteristics of clinical trials registered in these databases and their outcome, in terms of result reporting and publication are limited.

METHODS AND RESULTS

We searched for interventional, late-phase cardiovascular disease (CVD) studies in adults registered in Clinicaltrials.gov. first posted after 1/1/2013 and completed up to 31/12/2018. Data on study design, result reporting and publication were collected, and potential associations with a pre-defined set of explanatory factors were examined.In total, 250 CVD trials were included in the analysis. Of these, 193 (77.2%) were randomized studies, 99 (39.6%) open label designs, and 126 (50.4%) had industry as main sponsor. 179 trials (71.6%) evaluated the effect of drugs and 27 (10.8%) evaluated devices. The most common primary outcomes were non-clinical endpoints (76.0%), with only 17% of studies evaluating clinical endpoints. Industry-funded trials focused on patent-protected drugs and devices more often than non-industry-funded trials (72.0% vs. 30.6%, P < 0.001 and 55.0% vs. 26.3%, P = 0.033, respectively). Sixty three studies (25.2%) had results posted on clinicaltrials.gov, and 116 (46.4%) had results published in the scientific literature. In multivariate analysis, industry sponsorship was statistically significantly associated with results posting (OR: 3.38; 95% CI: 1.56-7.30, P = 0.002) and publication (OR: 0.41; 95% CI: 0.23-0.75, P = 0.004).

CONCLUSION

Among late-stage cardiovascular trials only 1/4 had results posted on clinicaltrials.gov and <50% had results published. Industry sponsors were more likely to invest in research on patent-protected drugs and devices than were non-industry sponsors. Industry-sponsored studies were more likely to have their results posted, but less likely to have their results published in the scientific literature.

The Inclusion of Economic Endpoints as Outcomes in Clinical Trials Reported to ClinicalTrials.gov

BACKGROUND

As medication expenditures rise, payers are increasingly demanding evidence of economic value for new medications. The 2015 Professional Society for Health Economics and Outcomes Research (ISPOR) Task Force on Cost-Effectiveness Analysis Alongside Clinical Trials noted that clinical trials are increasingly including health care utilization endpoints to address this rising interest in economic information.

OBJECTIVES

To (a) describe the prevalence of economic endpoints in clinical trials submitted to ClinicalTrials.gov and (b) examine associations between trial characteristics and the inclusion of economic endpoints.

METHODS

This retrospective review of ClinicalTrials.gov data extracted the characteristics of clinical trials that were submitted to ClinicalTrials.gov from January 2004 to December 2018; studied a drug and/or biological; and had a recruitment status of not yet recruiting, recruiting, active but not recruiting, or completed. Studies were classified as containing an economic endpoint based on 2 independent evaluations of the inclusion of endpoints relevant to costs, resource utilization, cost-effectiveness, productivity, absenteeism, presenteeism, or unemployment. Descriptive statistics were used to summarize trial characteristics, and chi-square analyses were used to evaluate differences in characteristics between trials with and without economic endpoints.

RESULTS

Of the 104,885 trials included in the study, 1,437 (1.37%) included an economic endpoint; among later phase (phase 2/3, 3, 4) trials, 939 (2.54%) included economic endpoints. Compared with studies that did not include economic endpoints, those that did were less often industry funded (48.0% vs. 52.0%, P < 0.001) and were for a high-spend specialty condition (24.1% vs. 27.4%, P < 0.001). The proportion of trials that included economic endpoints increased by a small but significant amount over the time period studied, from 1.2% (2004-2008) to 1.6% (2014-2018; P < 0.001).

CONCLUSIONS

A small but growing number of clinical trials are including economic endpoints. This finding may reflect continued industry concerns surrounding the cost and logistical challenges of piggybacking economic data collection alongside clinical trials and/or manufacturers' preferences for modeling for value demonstration. Future research is needed to better understand barriers to the inclusion of economic endpoints as well as the degree to which incorporating health care resource utilization collected during clinical trials into early economic modeling may reduce payer concerns about model transparency and bias.

DISCLOSURES

No outside funding supported this study. Patterson reports past employment by Indivior, unrelated to this study. Mitchell has nothing to disclose. The research included in this study was presented as a nonreviewed student pharmacist poster at AMCP Nexus 2019; October 30-November 1, 2019; National Harbor, MD.

Adherence to clinical trial registration in countries of Latin America and the Caribbean, 2015

Objective

To determine the prevalence of clinical trial registration in the International Clinical Trial Registry Platform (ICTRP) for studies from Latin America and the Caribbean (LAC) and to identify the key characteristics that lead to prospective and retrospective registration.

Methods

A cross-sectional study identified published, clinical trial studies through a search of PubMed, LILACS (Latin American and Caribbean Center on Health Sciences Information), and the Cochrane Central Register of Controlled Trials. Studies were included if published on 1 January – 31 December 2015, at least one author was affiliated with at least one LAC country, the clinical trial was conducted in at least one LAC site, and the full text of the article was available. A manual search of reference lists was also conducted. ICTRP registration information and key trial characteristics were compared.

Results

Of 1 502 CT references that met inclusion criteria, 297 were randomly-selected, 90.9% of which were published in English, 65% from Brazil, and 76.8% had a LAC author as the first author. The proportion of CT registered in the ICTRP was 59.9 %, of which 51.7% were registered prospectively. Clinicaltrials.gov was most frequently used registry (84.8%), followed by the Registro Brasileiro de Ensaios Clínicos and the Registro Público Cubano de Ensayos Clínicos. Key characteristics that favored registration were being in study phase 3 or 4 or being a multi-center study. Data was compared to a similar study from 2013 that reported a registration rate of only 19.8%.

Conclusions

Registration adherence and prospective registration have increased in LAC in recent years, but the proportion of unregistered CT remains high. While there are still many challenges to overcome, the adherence strategies implemented in recent years have proven effective.

Discontinuation and non-publication of clinical trials in cardiovascular medicine

BACKGROUND

Appropriate dissemination of clinical data is crucial for minimising bias. Despite this, high rates of study discontinuation and non-publication have been reported among clinical trials. Cardiovascular medicine receives a substantial proportion of academic funding; however, predictors of non-publication among cardiovascular trials are not well-established.

METHODS

The National Clinical Trials database was searched for cardiovascular trials completed between January 2010 and January 2014. Associated publications were identified in Medline or Embase. Relevant variables were extracted and subject to chi-squared and logistic regression to identify predictors of discontinuation and non-publication.

RESULTS

After reviewing 2035 trials, 431 trials were included, of which 82.1% (n=354; 119,233 participants) were completed. Among completed trials, 70.3% (n=249; 99,095 participants) were published. Industry funding was associated with increased likelihood of non-publication (odds ratio [OR] 2.84; 95% confidence interval [CI] 1.47-5.51; P=0.002), while non-randomised studies were more likely to remain unpublished than randomised counterparts. Industry-funded studies were over three times more likely to be discontinued than those sponsored by academic institutions (OR 3.89; CI 1.54-9.83; P=0.004). Trials studying heart failure and atrial fibrillation were more likely to be discontinued compared to trials studying coronary artery disease (OR 2.83; CI 1.23-6.51; and OR 3.10; CI 1.21-7.96, respectively). Of the total 135,714 participants, 25,565 were recruited into unpublished studies.

CONCLUSIONS

Discontinuation and non-publication of cardiovascular trials are common, resulting in data from thousands of participants remaining unpublished. Funding source and randomisation are strong predictors of non-publication, while sponsor type, phase and blinding status are key predictors of discontinuation.

Reporting Compliance of Stroke Trials: Cross-Sectional Analysis

BACKGROUND

The FDA mandates timely reporting of all clinical trials conducted in the United States. However, often the results are not reported in a timely manner, resulting in wastage of finite resources. We assessed the reporting of results of completed stroke trials and compared the reporting trends between U.S. and non-U.S. stroke trials.

METHODS

We assessed consecutive clinical stroke trials registered as completed in ClinicalTrials.gov between January 1, 2008 and January 1, 2015. Descriptive data collected included study phase, study type, participant age, number of enrolled patients, study locations, start and primary completion dates, result availability, time to reporting (months), sponsorship, funding sources, and publication status. We also performed manual search for stroke trials in Pubmed, Web of Science, and Google scholar.

RESULTS

Out of a total 140 completed trials, 39 trials (35,359 patients) involved at least 1 U.S. center and 101 trials (58,542 patients) were conducted in non-U.S. centers. Of the trials involving at least a single U.S. center, 31 of 39 (79%) reported their results, whereas only 6 of 31 (19%) reported their results within 1 year. Of the trials conducted at non-U.S. centers, 72 of 101 (71%) reported their results, whereas results for 24 of 72 (33%) trials were available within a year of completion. The time to reporting of results was significantly lower for all the included clinical trials in the 2012-2014 period (P < .001, Cohen's d = .726) as compared to the 2008-2011 period.

CONCLUSION

Only one-fifth of completed stroke trials involving at least a single U.S. center report their results within 1 year. Additionally, every fifth completed trial involving stroke patients at U.S. centers remain unreported.

The Landscape of Clinical Trials Evaluating the Theranostic Role of PET Imaging in Oncology: Insights from an Analysis of ClinicalTrials.gov Database

In the war on cancer marked by personalized medicine, positron emission tomography (PET)-based theranostic strategy is playing an increasingly important role. Well-designed clinical trials are of great significance for validating the PET applications and ensuring evidence-based cancer care. This study aimed to provide a comprehensive landscape of the characteristics of PET clinical trials using the substantial resource of ClinicalTrials.gov database. We identified 25,599 oncology trials registered with ClinicalTrials.gov in the last ten-year period (October 2005-September 2015). They were systematically reviewed to validate classification into 519 PET trials and 25,080 other oncology trials used for comparison. We found that PET trials were predominantly phase 1-2 studies (86.2%) and were more likely to be single-arm (78.9% vs. 57.9%, P <0.001) using non-randomized assignment (90.1% vs. 66.7%, P <0.001) than other oncology trials. Furthermore, PET trials were small in scale, generally enrolling fewer than 100 participants (20.3% vs. 25.7% for other oncology trials, P = 0.014), which might be too small to detect a significant theranostic effect. The funding support from industry or National Institutes of Health shrunk over time (both decreased by about 5%), and PET trials were more likely to be conducted in only one region lacking international collaboration (97.0% vs. 89.3% for other oncology trials, P <0.001). These findings raise concerns that clinical trials evaluating PET imaging in oncology are not receiving the attention or efforts necessary to generate high-quality evidence. Advancing the clinical application of PET imaging will require a concerted effort to improve the quality of trials.

Trends in Research with U.S. Military Service Member Participants: A Population-Specific ClinicalTrials.gov Review

BACKGROUND

ClinicalTrials.gov reviews have evaluated research trends for specific conditions and age groups but not for specific populations of research participants. No ClinicalTrials.gov reviews have evaluated research with military service member participants.

PURPOSE

Study objectives were (a) to use ClinicalTrials.gov to identify trends in biomedical research from 2005 to 2014 in which U.S. military service members actively participated as research participants and (b) to describe a search strategy for adaptation in future ClinicalTrials.gov reviews of specific participant populations.

METHODS

A systematic review of ClinicalTrials.gov was performed to identify studies that included U.S. service members as participants, either exclusively or with other groups of participants.

RESULTS

U.S. service members were identified as participants in 512 studies. Service members participated together with other groups in 392 studies, while 120 studies included only service members. The top five conditions of interest were post-traumatic stress disorder, traumatic brain injury, amputations, burns, and ocular injuries/disorders. The number of studies started each year peaked in 2011 and declined from 2012 to 2014. Twenty-five percent of studies exclusive to service members aimed to enroll 500 or more participants. Research exclusive to Guard and Reserve service members during this period was limited.

CONCLUSIONS

U.S. military service members participate in biomedical research. To address the health needs of U.S. service members, it is important to ensure there is not a prolonged decline in research among this population. The search strategy may be adapted to ClinicalTrials.gov reviews of specific participant populations for which straightforward searches are not possible.

What to Expect From the Evolving Field of Geriatric Cardiology

The population of older adults is expanding rapidly, and aging predisposes to cardiovascular disease. The principle of patient-centered care must respond to the preponderance of cardiac disease that now occurs in combination with the complexities of old age. Geriatric cardiology melds cardiovascular perspectives with multimorbidity, polypharmacy, frailty, cognitive decline, and other clinical, social, financial, and psychological dimensions of aging. Although some assume that a cardiologist may instinctively cultivate some of these skills over the course of a career, we assert that the volume and complexity of older cardiovascular patients in contemporary practice warrants a more direct approach to achieve suitable training and a more reliable process of care. We present a rationale and vision for geriatric cardiology as a melding of primary cardiovascular and geriatrics skills, thereby infusing cardiology practice with expanded proficiencies in diagnosis, risks, care coordination, communications, end-of-life, and other competences required to best manage older cardiovascular patients.

Clinical trials in peripheral vascular disease: pipeline and trial designs: an evaluation of the ClinicalTrials.gov database

BACKGROUND

Tremendous advances have occurred in therapies for peripheral vascular disease (PVD); until recently, however, it has not been possible to examine the entire clinical trial portfolio of studies for the treatment of PVD (both arterial and venous disease).

METHODS AND RESULTS

We examined interventional trials registered in ClinicalTrials.gov from October 2007 through September 2010 (n=40,970) and identified 676 (1.7%) PVD trials (n=493 arterial only, n=170 venous only, n=13 both arterial and venous). Most arterial studies investigated lower-extremity peripheral artery disease and acute stroke (35% and 24%, respectively), whereas most venous studies examined deep vein thrombosis/pulmonary embolus prevention (42%) or venous ulceration (25%). A placebo-controlled trial design was used in 27% of the PVD trials, and 4% of the PVD trials excluded patients >65 years of age. Enrollment in at least 1 US site decreased from 51% of trials in 2007 to 41% in 2010. Compared with noncardiology disciplines, PVD trials were more likely to be double-blinded, to investigate the use of devices and procedures, and to have industry sponsorship and assumed funding source, and they were less likely to investigate drug and behavioral therapies. Geographic access to PVD clinical trials within the United States is limited to primarily large metropolitan areas.

CONCLUSIONS

PVD studies represent a small group of trials registered in ClinicalTrials.gov, despite the high prevalence of vascular disease in the general population. This low number, compounded by the decreasing number of PVD trials in the United States, is concerning and may limit the ability to inform current clinical practice of patients with PVD.

The landscape of clinical trials in nephrology: a systematic review of Clinicaltrials.gov

BACKGROUND

Well-designed trials are of paramount importance in improving the delivery of care to patients with kidney disease. However, it remains unknown whether contemporary clinical trials within nephrology are of sufficient quality and quantity to meet this need.

STUDY DESIGN

Systematic review.

SETTING & POPULATION

Studies registered with ClinicalTrials.gov.

SELECTION CRITERIA FOR STUDIES

Interventional (ie, nonobservational) studies (both randomized and nonrandomized) registered between October 2007 and September 2010 were included for analysis. Studies were reviewed independently by physicians and classified by clinical specialty.

PREDICTOR

Nephrology versus cardiology versus other trials.

OUTCOMES

Select clinical trial characteristics.

RESULTS

Of 40,970 trials overall, 1,054 (2.6%) were classified as nephrology. Most nephrology trials were for treatment (75.4%) or prevention (15.7%), with very few diagnostic, screening, or health services research studies. Most nephrology trials were randomized (72.3%). Study designs included 24.9% with a single study group, 64.0% that included parallel groups, and 9.4% that were crossover trials. Nephrology trials, compared with 2,264 cardiology trials (5.5% overall), were more likely to be smaller (64.5% vs 48.0% enrolling≤100 patients), phases 1-2 (29.0% vs 19.7%), and unblinded (66.2% vs 53.3%; P<0.05 for all). Nephrology trials also were more likely than cardiology trials to include a drug intervention (72.4% vs 41.9%) and less likely to report having a data monitoring committee (40.3% vs 48.5%; P<0.05 for all). Finally, there were few trials funded by the National Institutes of Health (NIH; 3.3%, nephrology; 4.2%, cardiology).

LIMITATIONS

Does not include all trials performed worldwide, and frequent categorization of funding source as university may underestimate NIH support.

CONCLUSIONS

Critical differences remain between clinical trials in nephrology and other specialties. Improving care for patients with kidney disease will require a concerted effort to increase the scope, quality, and quantity of clinical trials within nephrology.