Racial differences in low natriuretic peptide levels: Implications for heart failure clinical trials

BACKGROUND

Some patients with heart failure (HF) have low natriuretic peptide (NP) levels. It is unclear whether specific populations are disproportionately excluded from participation in randomized clinical trials (RCT) with inclusion requirements for elevated NPs. We investigated factors associated with unexpectedly low NP levels in a cohort of patients hospitalized with HF, and the implications on racial diversity in a prototype HF RCT.

METHODS

We created a retrospective cohort of 31,704 patients (age 72 ± 16 years, 49% female, 52% Black) hospitalized with HF from 2010 to 2020 with B-type natriuretic peptide (BNP) measurements. Factors associated with unexpectedly low BNP levels (<50 pg/mL) were identified using multivariable logistic regression models. We simulated patient eligibility for a prototype HF trial using specific inclusion and exclusion criteria, and varying BNP cut-offs.

RESULTS

Unexpectedly low BNP levels were observed in 8.9% of the cohort. Factors associated with unexpectedly low BNP levels included HFpEF (aOR 3.76, 95% CI: 3.36, 4.20), obesity (aOR 1.96, 95% CI: 1.73, 2.21), self-identification as Black (aOR 1.53, 95% CI: 1.36, 1.71), and male gender (aOR 1.45, 95% CI: 1.31, 1.60). Applying limited clinical inclusion and exclusion criteria from PARAGLIDE-HF disproportionately excluded Black patients, with impairment in renal function having the greatest impact. Adding thresholds for BNP of ≥35, ≥50, ≥67, ≥100, and ≥150 pg/mL demonstrated the risk of exclusion was higher for Black compared to non-Black patients (RR = 2.03 [95% CI: 1.73, 2.39], 1.90 [95% CI: 1.68, 2.15], 1.63 [95% CI: 1.48, 1.81], 1.38 [95% CI: 1.28, 1.50], and 1.23 [95% CI: 1.15, 1.31], respectively).

CONCLUSIONS

Nearly 10% of patients hospitalized with HF have unexpectedly low BNP levels. Simulating inclusion into a prototype HFpEF RCT demonstrated that requiring increasingly elevated NP levels disproportionately excludes Black patients.

Novel Measures of Arterial Hemodynamics and Wave Reflections Associated With Clinical Outcomes in Patients With Heart Failure

Background Arterial stiffness and earlier wave reflections can increase afterload and impair cardiovascular function. Most prior studies have been performed in patients with preserved left ventricular function. We describe novel measures of pulsatile arterial hemodynamics and their association with clinical outcomes in patients with heart failure with reduced ejection fraction. Methods and Results Participants with heart failure with reduced ejection fraction (n=137, median age 56 years, 49% women, 58% Black) and age-matched healthy controls (n=124) underwent measurements of large artery stiffness and pulsatile arterial hemodynamics. Carotid-femoral pulse wave velocity and augmentation index were assessed using radial applanation tonometry. Pressure-flow analyses derived reflected wave transit time, the systolic pressure-time integral imposed by proximal aortic characteristic impedance, and the pressure-time integral from wave reflection (wasted pressure effort). Cox proportional hazards models defined associations between hemodynamic measures and (1) all-cause death and (2) a combined end point of left ventricular assist device implant, heart transplant, and death, at 2 years adjusted for race, BNP (B-type natriuretic peptide), and the Meta-Analysis Global Group in Chronic Heart Failure Risk Score. Compared with controls, participants with heart failure with reduced ejection fraction exhibited similar carotid-femoral pulse wave velocity (6.8±1.6 versus 7.0±1.6 m/s, P=0.40) but higher augmentation index normalized to a heart rate of 75 bpm (13±2% versus 22±2%, P<0.001). Shorter reflected wave transit time (ie, earlier wave reflection arrival to the proximal aorta) was associated with an increased risk of death (adjusted hazard ratio [aHR] 1.67 [95% CI 1.03-1.63]) and the combined end point of death/left ventricular assist device/heart transplant (aHR, 1.61 [95% CI, 1.06-2.44]) at 2 years. Wasted pressure effort/proximal aortic characteristic impedance, representing the proportion of systolic load from wave reflection versus aortic root characteristic impedance, was univariately associated with death (hazard ratio (HR), 1.44 [95% CI, 1.05-1.97]) and with death/left ventricular assist device/heart transplant on univariate (HR, 1.42 [95% CI, 1.07-1.88]) and multivariable (aHR, 1.40 [95% CI, 1.02-1.93]) analysis. Conclusions Increased left ventricular systolic load from premature wave reflections is associated with adverse clinical outcomes in patients with heart failure with reduced ejection fraction.

Toward Meeting the Obligation of Respect for Persons in Pragmatic Clinical Trials

Research ethics oversight systems have traditionally emphasized the informed consent process as the primary means by which to demonstrate respect for prospective subjects. Yet how researchers can best fulfill the ethical obligations of respect for persons in pragmatic clinical trials (PCTs)-particularly those that may alter or waive informed consent-remains unknown. We propose eight dimensions of demonstrating respect in PCTs: (1) engaging patients and communities in research design and execution, (2) promoting transparency and open communication, (3) maximizing agency, (4) minimizing burdens and promoting accessibility, (5) protecting privacy and confidentiality, (6) valuing interpersonal interactions with clinicians and study team members, (7) providing compensation, and (8) maximizing social value. While what respect requires in the context of PCTs will vary based on the nature of the PCT in question, the breadth of these dimensions demonstrates that respect obligations extend beyond informed consent processes.

Excess 30-Day Heart Failure Readmissions and Mortality in Black Patients Increases With Neighborhood Deprivation

BACKGROUND

Longstanding racial disparities in heart failure (HF) outcomes exist in the United States, in part, due to social determinants of health. We examined whether neighborhood environment modifies the disparity in 30-day HF readmissions and mortality between Black and White patients in the Southeastern United States.

METHODS

We created a geocoded retrospective cohort of patients hospitalized for acute HF within Emory Healthcare from 2010 to 2018. Quartiles of the Social Deprivation Index characterized neighborhood deprivation at the census tract level. We estimated the relative risk of 30-day readmission and 30-day mortality following an index hospitalization for acute HF. Excess readmissions and mortality were estimated as the absolute risk difference between Black and White patients within each Social Deprivation Index quartile, adjusted for geographic clustering, demographic, clinical, and hospital characteristics.

RESULTS

The cohort included 30 630 patients, mean age 66 years, 48% female, 53% Black. Compared with White patients, Black patients were more likely to reside in deprived census tracts and have higher comorbidity scores. From 2010 to 2018, 29.4% of Black and 23.0% of White patients experienced either a 30-day HF readmission or 30-day death (P<0.001). Excess in composite 30-day HF readmissions and mortality for Black patients ranged from 3.9% (95% CI, 1.5%-6.3%; P=0.0002) to 6.8% (95% CI, 4.1%-9.5%; P<0.0001) across Social Deprivation Index quartiles. Accounting for traditional risk factors did not eliminate the Black excess in combined 30-day HF readmissions or mortality in any of the neighborhood quartiles.

CONCLUSIONS

Excess 30-day HF readmissions and mortality are present among Black patients in every neighborhood strata and increase with progressive neighborhood socioeconomic deprivation.

Conflicting Perspectives on the Value of Neprilysin Inhibition in Heart Failure Revealed During Development of a Decision Aid Focusing on Patient Costs for Sacubitril/Valsartan

BACKGROUND

Despite concerns about rising costs in health care, cost is rarely an issue discussed by patients and clinicians when making treatment decisions in a clinical setting. This study aimed to understand stakeholder perspectives on a patient decision aid (PtDA) meant to help patients with heart failure choose between a generic and relatively low-cost heart failure medication (ACE [angiotensin-converting enzyme] inhibitor or angiotensin II receptor blocker) and a newer, but more expensive, heart failure medication (angiotensin II receptor blocker neprilysin inhibitor).

METHODS AND RESULTS

Feedback on the PtDA was solicited from 26 stakeholders including patients, clinicians, and the manufacturer. Feedback was recorded and discussed among development team members until consensus regarding both the interpretation of the data and the appropriate changes to the PtDA was reached. Stakeholders found the PtDA sufficient in clarifying the different treatment options for heart failure. However, patients, physicians, and the manufacturer had different opinions on the importance of highlighting cost in a PtDA. Patients indicated issues of cost were crucial to the decision while physicians and manufacturers expressed that the cost issue was secondary and should be de-emphasized.

CONCLUSIONS

The stratified perspectives on the role of cost in medical decision-making expressed by our participants underscore the importance and challenge of having clear, frank discussions during clinic visits about treatment cost and perceived value.

Justifying Clinical Nudges

The shift away from paternalistic decision-making and toward patient-centered, shared decision-making has stemmed from the recognition that in order to practice medicine ethically, health care professionals must take seriously the values and preferences of their patients. At the same time, there is growing recognition that minor and seemingly irrelevant features of how choices are presented can substantially influence the decisions people make. Behavioral economists have identified striking ways in which trivial differences in the presentation of options can powerfully and predictably affect people's choices. Choice-affecting features of the decision environment that do not restrict the range of choices or significantly alter the incentives have come to be known as "nudges." Although some have criticized conscious efforts to influence choice, we believe that clinical nudges may often be morally justified. The most straightforward justification for nudge interventions is that they help people bypass their cognitive limitations-for example, the tendency to choose the first option presented even when that option is not the best for them-thereby allowing people to make choices that best align with their rational preferences or deeply held values. However, we argue that this justification is problematic. We argue that, if physicians wish to use nudges to shape their patients' choices, the justification for doing so must appeal to an ethical and professional standard, not to patients' preferences. We demonstrate how a standard with which clinicians and bioethicists already are quite familiar-the best-interest standard-offers a robust justification for the use of nudges.

Abstract 224: Why Do Patients Decline to Participate in Heart Failure Trials?

Background: Randomized controlled trials (RCTs) remain the gold standard in establishing clinical efficacy. However, low patient enrollment escalates costs of conducting trials and selective enrollment leads to under-representation of the real-world population. Limited data exists on why patients decline participation in RCTs and what factors may lead to increased participation rates.

Methods: In-person and telephone interviews were conducted with 20 patients with congestive heart failure who declined participation in a RCT using a semi-structured interview guide. Questions assessed comprehension of the trial they were approached for, perceived risks and benefits, perception about the recruiter, rationale behind declining participation, and suggestions to improve participation. Qualitative descriptive analysis was conducted of transcribed responses.

Results: Participants’ median age was 63 years (IQR 51.5-69), 50% were female, and 60% were African-American. Only 6 participants could accurately describe the intervention and understood design of the trial in which they were asked to participate. Majority of the participants (n=15) had a positive view of the recruiter who approached them. Most participants made the decision to not participate quickly while only 2 participants took extended time to deliberate. The most common reasons for not participating was due to concern for adverse events from the intervention being studied (n=15) and because participation was thought to be too burdensome (n=10). Other reasons for not participating included mistrust of research staff (n=3), concern for receiving inadequate treatment (n=3) and lack of involvement or consultation with the patient’s physician (n=3). The most common suggestion provided to increase participant recruitment was involving primary care physicians or cardiologists known to the patients. Overall, 5 decliners reported previously participating in research studies stating prior participation was less burdensome (n=2), they were previously approached by physicians known to them (n=2) or their health was better and participation seemed less risky (n=1).

Conclusion: Slow participant enrollment in clinical trials threatens our ability to produce timely data necessary to guide clinical practice, while increasing cost of conducting them. The most common suggestion to improve participation made by patients who declined enrollment in a clinical trial was engaging physicians known to the patient in the process of recruitment while making participation less burdensome. Accordingly, educating potential participants regarding clinical trials, clarifying study risks and benefits with incorporation of design features that reduce burden such as frequency of invasive testing and follow-up visits can help increase participation rates.

Implementation of the exception from informed consent regulations in a large multicenter emergency clinical trials network: the RAMPART experience

Clinical trials investigating therapies for acutely and critically ill and injured patients in the earliest phases of treatment often can only be performed under regulations allowing for exception from informed consent (EFIC) for emergency research. Implementation of these regulations in multicenter clinical trials involves special challenges and opportunities. The Rapid Anticonvulsant Medication Prior to Arrival Trial (RAMPART), the first EFIC trial conducted by the Neurological Emergencies Treatment Trials (NETT) network, combined centralized resources and coordination with retention of local control and flexibility to facilitate compliance with the EFIC regulations. Specific methods used by the NETT included common tools for community consultation and public disclosure, sharing of experiences and knowledge, and reporting of aggregate results. Tracking of community consultation and public disclosure activities and feedback facilitates empirical research on EFIC methods in the network and supports quality improvements for future NETT trials. The NETT model used in RAMPART demonstrates how EFIC may be effectively performed in established clinical trial networks.

Ancillary care obligations of medical researchers

An investigator planning a study in Africa of the prevalence of pulmonary hypertension in children with severe malaria anticipates that she and her team will encounter significant unmet health needs during the course of the study. She recognizes that study procedures, particularly echocardiography, may identify and diagnose conditions that are not treatable within the local health system due to resource constraints. Aware that some of these needs may be serious, as well as difficult and costly to treat, she asks the bioethics consultation service for assistance in determining the extent to which she as an investigator has a responsibility to provide clinical care for conditions that she finds while conducting the study. This article reviews the issue of investigators' responsibilities to meet participants' needs for ancillary care and argues that investigators can have a responsibility to provide care for a wide range of health needs, including at times care for conditions not connected to the research question or study procedures. That responsibility, however, is significantly limited by the depth of the investigator's relationship with participants and the resource demands of providing such care.

Excluding particular information from consent forms

Although the informed consent process is crucial to protecting human research subjects, there are cases when particular information within the consent form may present risks to those subjects. In this paper, we examine a case in which including the sponsor's name on the consent form may allow the form to serve as a surrogate for subjects' HIV status. There is no literature addressing the ethical acceptability of excluding particular information from consent forms, and there exists little regulatory guidance on this issue. We argue that excluding information from the consent form is, in fact, obligatory when that information is disclosed orally during the consent process but its presence on the form poses risks to the subjects the consent process is designed to protect. Further, we argue that the regulations ought to be amended to reflect this obligation.

Ethical goals of community consultation in research

In response to the traditional emphasis on the rights, interests, and well-being of individual research subjects, there has been growing attention focused on the importance of involving communities in research development and approval. Community consultation is a particularly common method of involving communities. However, the fundamental ethical goals of community consultation have not been delineated, which makes it difficult for investigators, sponsors, and institutional review boards to design and evaluate consultation efforts. Community consultation must be tailored to the communities in which it is conducted, but the purposes of consultation-the ethical goals it is designed to achieve-should be universal. We propose 4 ethical goals that give investigators, sponsors, institutional review boards, and communities a framework for evaluating community consultation processes.

An analysis of U.S. practices of paying research participants

BACKGROUND

Despite controversy about paying research subjects, little is known about actual practices in the U.S., including what type of studies offer payment, to what type of subjects, and how amounts are determined.

OBJECTIVE

To document current U.S. practices regarding payment to research subjects.

METHODS

The protocols and consent forms of 467 studies offering payment to research subjects approved by 11 IRBs across the U.S. were reviewed to analyze how they describe and justify payment to subjects.

RESULTS

Money was offered in a wide variety of study types, from short term physiologic studies to large clinical trials of therapeutic interventions, to both patient (61%) and healthy (24.4%) subjects or both (14.6%). Dollar amounts varied widely and were infrequently explicitly described as based on time (19%) or procedures (12%). Unexplained variation in dollar amounts occurred in similar studies or in the same (multi-site) study at different sites, and for similar procedures across studies sometimes even within one site. Although the range was wide ($5-$2000), total amounts were usually modest (overall median $155), and almost always described in the consent form (94.4%) and usually as pro-rated (73%).

CONCLUSIONS

Both patient and healthy subjects are offered payment in a wide variety of types of research in the U.S. Variation in the dollar amounts offered is largely unexplained.

Paying research subjects: an analysis of current policies

BACKGROUND

Few data are available on guidelines used by research organizations to make decisions about paying subjects.

OBJECTIVE

To analyze existing guidance regarding payment of research subjects and to identify common characteristics and areas for further research.

DESIGN

Descriptive content analysis of policies.

MEASUREMENTS

Written policies and rules of thumb about paying subjects from 32 U.S. research organizations.

RESULTS

Of 32 organizations, 37.5% had written guidelines about paying subjects; all but 1 reported having rules of thumb. Few (18.8%) were able to provide a confident estimate of the proportion of studies that pay subjects. Organizations reported that investigators and institutional review boards make payment decisions and that both healthy and ill subjects in some studies are paid for their time (87%), for inconvenience (84%), for travel (68%), as incentive (58%), or for incurring risk (32%). Most organizations require that payment be prorated (84%) and described in the consent document (94%).

CONCLUSIONS

Most organizations pay some research subjects, but few have written policies on payment. Because investigators and institutional review boards make payment decisions with little specific guidance, standards vary.

The consent process for cadaveric organ procurement: how does it work? How can it be improved?

CONTEXT

Understanding the consent process that organ procurement organizations (OPOs) use is crucial to improving the process and thereby reducing the number of individuals who die each year for want of an organ transplant. However, no data exist on OPOs' current consent practices.

OBJECTIVE

To assess whose wishes OPOs follow when procuring solid organs from deceased individuals and whether advance directives and computerized registries might improve the consent process for solid organ procurement.

DESIGN, SETTING, AND PARTICIPANTS

Telephone survey conducted from June to August 1999 of all 61 active OPOs.

MAIN OUTCOME MEASURES

Responses to the 49-question survey addressing consent practices in specific scenarios of deceased and next of kin wishes.

RESULTS

Widespread divergence exists in OPOs' consent practices for cadaveric solid organ procurement. Regarding overall consent practices, 19 (31%) OPOs reported that they follow the deceased's wishes, 19 (31%) follow the next of kin's wishes, 13 (21%) procure organs if neither party objects, 8 (13%) procure organs if either party consents or neither objects, and 2 (3%) do not follow any of these 4 overall practices. These differences appear to be traceable to implicit ethical disagreements about whose wishes should be followed. A total of 29 (48%) OPOs reported having an official policy to address whether they follow the family's or deceased's wishes. Regarding factors that influence OPOs' choice of consent practice, 29 (48%) respondents ranked impact on the deceased's family as the most important factor, 13 (21%) ranked state law as most important, and 7 (11%) ranked the priority of the deceased's wishes as most important. Durable power of attorney appeared to have substantial weight in OPOs' decisions; for example, in the scenario in which the deceased supported organ donation and the next of kin opposed it, 34 (56%) OPOs reported they were likely to procure organs based on the consent of the holder of the deceased's durable power of attorney, whereas only 7 (11%) reported they were likely to procure organs based on a document of gift (a living will, donor card, or driver's license).

CONCLUSIONS

Expanding the legal scope of living wills to cover individuals' organ donation preferences would likely have little impact on procurement rates. In contrast, expanding the legal scope of durable powers of attorney for health care may have a significant impact. A national discussion should take place addressing the underlying ethical issues that appear to account for much of the divergence among OPOs' consent practices for cadaveric solid organ procurement.