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

Characteristics of contemporary atrial fibrillation clinical trials and their association with industry sponsorship

BACKGROUND

Industry sponsorship is an important source of funding for atrial fibrillation (AF) clinical trials, the implications of which have not been analyzed.

OBJECTIVE

The purpose of this study was to determine the characteristics of contemporary AF clinical trials and to evaluate their association with funding source.

METHODS

We systematically assessed all completed AF trials registered in the ClinicalTrials.gov database between conception to October 31, 2023, and extracted publicly available information including funding source, trial size, demographic distribution, intervention, location, and publication status. Trial characteristics were compared using the Wilcoxon rank-sum test and Fisher exact test for continuous and categorical variables, respectively.

RESULTS

Of the 253 clinical trials assessed, 171 (68%) reported industry funding. Industry funding was associated with a greater median number of patients enrolled (172 vs 80; P <.001), publication rate (56.7% vs 42.7%; P = .04), probability of being product-focused (48.0% vs 24.4%; P <.001), and multicontinental recruitment location (25.2% vs 2.4%; P <.001) when compared to nonindustry-funded trials. However, industry funding was not associated with a significant difference in median impact factor (7.7 vs 7.7; P = .723). The overall proportion of industry-funded trials did not change over time (P = 1).

CONCLUSION

Industry-funded clinical trials in AF often are larger, more frequently published, multicontinental, and product-focused. Industry funding was found to be associated with significant differences in study enrollment and publication metrics.

Torsemide Versus Furosemide After Discharge in Patients Hospitalized With Heart Failure Across the Spectrum of Ejection Fraction: Findings From TRANSFORM-HF

BACKGROUND

The TRANSFORM-HF trial (Torsemide Comparison With Furosemide for Management of Heart Failure) found no significant difference in all-cause mortality or hospitalization among patients randomized to a strategy of torsemide versus furosemide following a heart failure (HF) hospitalization. However, outcomes and responses to some therapies differ by left ventricular ejection fraction (LVEF). Thus, we sought to explore the effect of torsemide versus furosemide by baseline LVEF and to assess outcomes across LVEF groups.

METHODS

We compared baseline patient characteristics and randomized treatment effects for various end points in TRANSFORM-HF stratified by LVEF: HF with reduced LVEF, ≤40% versus HF with mildly reduced LVEF, 41% to 49% versus HF with preserved LVEF, ≥50%. We also evaluated associations between LVEF and clinical outcomes. Study end points were all-cause mortality or hospitalization at 30 days and 12 months, total hospitalizations at 12 months, and change from baseline in Kansas City Cardiomyopathy Questionnaire clinical summary score.

RESULTS

Overall, 2635 patients (median 64 years, 36% female, 34% Black) had LVEF data. Compared with HF with reduced LVEF, patients with HF with mildly reduced LVEF and HF with preserved LVEF had a higher prevalence of comorbidities. After adjusting for covariates, there was no significant difference in risk of clinical outcomes across the LVEF groups (adjusted hazard ratio for 12-month all-cause mortality, 0.91 [95% CI, 0.59-1.39] for HF with mildly reduced LVEF versus HF with reduced LVEF and 0.91 [95% CI, 0.70-1.17] for HF with preserved LVEF versus HF with reduced LVEF; P=0.73). In addition, there was no significant difference between torsemide and furosemide (1) for mortality and hospitalization outcomes, irrespective of LVEF group and (2) in changes in Kansas City Cardiomyopathy Questionnaire clinical summary score in any LVEF subgroup.

CONCLUSIONS

Despite baseline demographic and clinical differences between LVEF cohorts in TRANSFORM-HF, there were no significant differences in the clinical end points with torsemide versus furosemide across the LVEF spectrum. There was a substantial risk for all-cause mortality and subsequent hospitalization independent of baseline LVEF.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03296813.

Temporal trends in evidence supporting therapeutic interventions in heart failure and other European Society of Cardiology guidelines

AIMS

This study aimed to determine whether any change occurred over time in level of evidence (LoE) of therapeutic interventions supporting heart failure (HF) and other European Society of Cardiology guideline recommendations.

METHODS AND RESULTS

We selected topics with at least three documents released between 2008 and April 2022. Classes of recommendations (CoR) and supporting LoE related to therapeutic interventions within each document were collected and compared over time. A total of 1822 recommendations from 18 documents on 6 topics [median number per document = 112, 867 (48%) CoR I] were included in the analysis. There was a trend towards a reduction over time in the percentage of CoR I in HF (46-36-34%), non-ST elevation myocardial infarction (NSTEMI; 78-58-54%), and pulmonary embolism (PE; 65-50-39%) guidelines, with a decrease in the total number of recommendations for HF only. Percentage of CoR I was stable over time around 40% for valvular heart disease (VHD) and atrial fibrillation (AF), and around 60% for cardiovascular prevention (CVP), with an increase in the total number of recommendations for VHD and CVP and a decrease for AF. Among CoR I, 319 (37%) were supported by LoE A, with a decrease over time for HF (56-46-42%), an increase for NSTEMI (29-38-48%) and AF (28-31-36%), a bimodal distribution for PE and CVP, and a lack for VHD.

CONCLUSIONS

LoE supporting therapeutic recommendations in contemporary European guidelines is generally low. Physicians should be aware of these limitations, and scientific societies promote a greater understanding of their significance and drive future research directions.

Early discontinuation and results reporting of robot-assisted surgery studies registered on ClinicalTrials.gov: a research on research study

OBJECTIVES

In this study, we aimed to investigate the characteristics of robot-assisted surgery studies registered on ClinicalTrials.gov and identify factors associated with early trial discontinuation and timely results reporting.

DESIGN

We searched ClinicalTrials.gov to identify interventional studies on robot-assisted surgery on 24 May 2021. All structured information of the potential studies was downloaded and reviewed. A descriptive analysis was performed. Logistic and Cox regression analyses were respectively performed to determine the significance of the association of study characteristics with results reporting and early discontinuation.

RESULTS

A total of 529 interventional studies on robot-assisted surgery were included, with 45 studies reporting results and 54 studies being stopped early. Of the 289 due studies, only 45 (16%) had submitted their results, and only 6 (2%) had submitted their results within the 1-year deadline. Funding source was associated with results reporting: academic funded were 63% less likely than industry to report results (OR=0.37, 95% CI: 0.16 to 0.83, p=0.02). Studies related to device feasibility were associated with greater risk of early discontinuation compared to treatment-related studies (HR=2.30, 95% CI: 1.08 to 4.89, p=0.03). Surprisingly, National Institutes of Health-funded studies were at greater hazard of discontinuation compared to industry-funded studies (HR=3.30, 95% CI: 1.09 to 10.00, p=0.04).

CONCLUSIONS

There was poor compliance with results reporting requirements for robot-assisted surgical studies. It is important that investigators remain informed about the regulatory requirements, and should be helped to develop a sense of responsibility for reporting results. Also, they need to ensure the careful design of the study protocol and adequate resources to reduce the risk of early discontinuation.

Evidence for stratified conflicts of interest policies in research contexts: a methodological review

OBJECTIVES

The purpose of this study was to conduct a methodological review of research on the effects of conflicts of interest (COIs) in research contexts.

DESIGN

Methodological review.

DATA SOURCES

Ovid.

ELIGIBILITY CRITERIA

Studies published between 1986 and 2021 conducting quantitative assessments of relationships between industry funding or COI and four target outcomes: positive study results, methodological biases, reporting quality and results-conclusions concordance.

DATA EXTRACTION AND SYNTHESIS

We assessed key facets of study design: our primary analysis identified whether studies stratified industry funding or COI variables by magnitude (ie, number of COI or disbursement amount), type (employment, travel fees, speaking fees) or if they assessed dichotomous variables (ie, conflict present or absent). Secondary analyses focused on target outcomes and available effects measures.

RESULTS

Of the 167 articles included in this study, a substantial majority (98.2%) evaluated the effects of industry sponsorship. None evaluated associations between funding magnitude and outcomes of interest. Seven studies (4.3%) stratified industry funding based on the mechanism of disbursement or funder relationship to product (manufacturer or competitor). A fifth of the articles (19.8%) assessed the effects of author COI on target outcomes. None evaluated COI magnitude, and three studies (9.1%) stratified COI by disbursement type and/or reporting practices. Participation of an industry-employed author showed the most consistent effect on favourability of results across studies.

CONCLUSIONS

Substantial evidence demonstrates that industry funding and COI can bias biomedical research. Evidence-based policies are essential for mitigating the risks associated with COI. Although most policies stratify guidelines for managing COI, differentiating COIs based on the type of relationship or monetary value, this review shows that the available research has generally not been designed to assess the differential risks of COI types or magnitudes. Targeted research is necessary to establish an evidence base that can effectively inform policy to manage COI.