Challenges of Cardiology Clinical Trials: Representing the Underrepresented

Male doctor measures blood pressure to assess a patient's cardiovascular health.

Cardiology clinical trials play a crucial role in the development of new treatments for heart diseases. However, these trials often face several challenges, including the lack of patient diversity. The underrepresented groups, such as women, minorities, and elderly populations, are often not included in these trials, leading to a limited understanding of the effectiveness and safety of treatments in these groups. Investigations that include people of various backgrounds can provide better outcomes to a diverse group of patients upon approval.

Why is Diversity Needed in Cardiology Clinical Trials?

Diversity is needed in cardiovascular clinical trials to ensure that the treatments being developed are effective and safe for all patients, regardless of gender, ethnicity, or age. The heart is a complex organ, and diseases can present differently in different groups. A diverse patient population in clinical trials can provide a more comprehensive understanding of the treatment’s impact on different groups and help to address disparities in healthcare.

Moreover, including diverse participants in clinical trials can increase the generalizability of the results and make the treatments more accessible to a wider range of patients. Therefore, diversity is critical to the success of cardiovascular clinical trials and must be prioritized.

A History of Unequal Cardiovascular Healthcare

The lack of diversity in cardiovascular clinical research has resulted in unequal healthcare outcomes. Studies with poor representation of the general population may not accurately reflect the effectiveness or safety of treatments for all patients. This is particularly evident in cardiology clinical trials, where limited diversity can lead to the underrepresentation of certain populations, such as African Americans. While this is true across medicine, many examples of cardiology clinical trials demonstrate a need for greater diversity and inclusivity.

A cross-sectional study of the participation of Black US residents in trials for 24 novel cardiovascular drugs across seven indications approved by the FDA  between 2006 and 2020 showed that only 2.9% of the trial population were Black. The trial also calculated the participation-to-prevalence ratio (PPR), which estimates the proportion of participants from a group compared to the proportion of that group affected by the disease in the general population. A PPR between 0.8 and 1.2 would have indicated a correct proportionality of representation. However, the PPR for all CVD conditions for Blacks was 0.29, evidence of the underrepresentation of Blacks within these trials.

The African American population currently accounts for 13% of the US population and is projected to grow by 2060. A health survey by the CDC in 2018 shows that African Americans are 30% more likely to die from heart disease and 40% more likely to have high blood pressure than non-Hispanic Caucasians. Underrepresentation within past and current clinical trials put this population at a greater risk of poor outcomes from cardiovascular diseases.

To ensure effective and safe treatments for all patients, greater diversity and inclusivity must be prioritized in cardiovascular clinical trials.

What Happens When There is a Lack of Diversity in Clinical Trials

The omission of data regarding the race of the enrolled subjects in the past has made understanding the risk factors affecting minority populations difficult. The CAPRIE trial published in 1996 compared the efficacy and safety of clopidogrel versus aspirin in reducing the risk of thrombotic events. The results showed a relative risk reduction of 8.7% with clopidogrel therapy, with no significant difference in adverse events. However, African Americans have been found to have higher on-treatment platelet reactivity to clopidogrel and a higher rate of stent thrombosis after the implantation of drug-eluting stents.

Similar to the racial disparities seen in clinical trials and their consequences, the disproportionate representation of women in clinical research has negatively impacted their cardiovascular care.

Women represent 50% of the adult US population and 50% of heart failure patients. A study looking at the 10-year history of enrollment of women and minorities in pivotal cardiovascular trials funded by the FDA shows that women only represented 36% of trial participants. The insufficient number of participants in the subgroup analysis based on gender has lead to misinterpretation of the data. There are also sex-based differences in the way heart failure or heart attacks present, their risk factors, and pathophysiology, which have led to delayed diagnosis and treatment, and poorer outcomes of care in women.

Who Are the Underrepresented in Cardiology Clinical Trials?

Despite efforts made by government agencies and by individual sponsors, investigators, and CROs, the participation of the following groups in clinical trials remains low. Underrepresented groups in cardiovascular clinical trials can include, but are not limited to:

  • Racial/ethnic minorities, particularly African Americans, Hispanics, and Asians
  • Women
  • People of low socioeconomic status
  • Older adults
  • Disabled people
  • People with multiple comorbidities

It is important to note that each group has unique needs and experiences, and may respond differently to treatments. Ensuring diversity in cardiovascular clinical trials is essential for developing treatments that are effective and safe for all patients.

What Steps Can Overcome the Challenges Faced in Increasing Diversity in Cardiovascular Clinical Trials?

Enrolling more diverse research participants in cardiovascular clinical trials faces several barriers. However, there are strategies available to help overcome these challenges.

1. Use an intentional approach to increase diversity in the trial

When initially drafting a study design, it is important to identify the populations which will be treated with the therapy or device, and ensure that they are included. Similarly, it is important to outline a recruitment plan that entails specific tactics that will be used to make participation in the trial appealing to a diverse group of patients.

2. Provide increased access to the clinical trial

Access is a significant barrier for underrepresented populations. To increase enrollment of these populations:

  • Create outreach strategies to provide access to information about the clinical trial.
  • Provide trial information to HCPs in areas where the target population seeks treatment.
  • Set up more trial sites in parts of the US where the target population is more represented.
  • Provide transportation or some form of reimbursement to increase representation from low socioeconomic groups.
  • Leverage technology, such as virtual visits, digital recruitment, integration of EMRs, remote monitoring, and other digital health technology, to find more participants and decrease the need to travel to clinics unless necessary.

3. Generate trust

One of the major barriers to recruitment, especially amongst race and ethnic minorities, is a lack of trust that has resulted from a history of unethical practices, such as the Tuskegee Syphilis Study. Steps to increase trust are vital to improving the enrollment of diverse populations and may involve:

  • Listening to and addressing the concerns of the participants.
  • Removing misinformation and misconceptions regarding the disease and provide high-quality data and information about how it affects their specific population.
  • Ensuring representation of a diverse population amongst research staff and leadership, as 64% of participants think this is something important to consider before enrolling.
  • Demonstrating a clear advantage to joining the trial, such as access to the best treatment available.

4. Re-assess the inclusion/exclusion criteria

Eligibility criteria that are too strict have resulted in a significant lack of diversity in trials. Improvement in inclusivity must be made to ensure greater representation. We can do this by broadening the eligibility and minimizing the exclusion criteria based on:

  • Age
  • Gender
  • Sexuality
  • Pre-existing conditions

By implementing these strategies, researchers and clinical trial teams can overcome the challenges of increasing diversity in cardiovascular clinical trials and ensure that treatments are effective and safe for all patients.

How Cardiology CROs Are Addressing the Lack of Diversity in Clinical Trials

The need for increased diversity and inclusion within cardiology clinical trials has been evident for some time. Although progress has been made over the past few decades, representation of ethnic/racial minorities, women, the elderly, and the disabled are still insufficient. Clinical research organizations (CROs) can increase their representation in trials through recruitment and retention strategies that work intentionally to increase diversity, improve access, generate trust, and broaden eligibility criteria.

Vial Cardiology CRO is a tech-enabled CRO that supports cardiology clinical trials across multiple indications from start to close out. As your trusted CRO partner, we can help get your clinical site onboarding process up and running within 30 days. Through fixed-fee pricing and other strategies, we can significantly reduce the costs of your clinical trial. Using our integrated tech platform, which connects eSource, EDC, and ePRO on one system, we will increase the efficiency of your trial. Contact us here to see how we can help your clinical trial be as efficient, cost-effective, and diverse as possible.

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