In recent years, cardiovascular outcomes trials (CVOTs) have become prominent in studies of GLP-1 receptor agonists, demonstrating clinical heart health benefits of these blockbuster drugs. As long-term trials designed to assess a drug’s impact on cardiovascular (CV) health, CVOTs provide critical information on the safety and efficacy of treatment – even for non-CV drugs – protecting high-risk patients from serious events such as heart attack or stroke.
The case of Merck’s Vioxx – a nonsteroidal anti-inflammatory drug for arthritis and acute pain – illustrates the risks of inadequate oversight. Approved without dedicated CV safety studies, it was later withdrawn due to increased risk of heart attack and stroke.1 Vioxx remains a cautionary tale, underscoring the importance of CVOTs that safeguard participants, while prioritizing human factors – a coordination challenge central to trial success.
While these trials are critical to demonstrating clinical value, they can also be complex and costly. Among the most challenging aspects are the people involved – from patients to investigators and committee members – whose participation directly impacts trial timelines, internal consistency, endpoint data capture and the overall quality of the study.
Employing Strategic Patient Selection
Selecting the right patients for a CVOT is one of the first steps to a successful study. A pivotal element of this process is the inclusion/exclusion criteria, which can be used to enrich the study population for individuals at a higher risk of CV events within the trial timeframe. Selected correctly, these criteria can help to ensure that a study does not have to run over many years of follow-up, thereby reducing the resource commitment necessary.
An emerging tool for this purpose is polygenic risk scoring, which assesses an individual’s genetic predisposition to conditions such as heart disease. As these methods become more widely accepted, they have the potential to guide CVOT patient selection. Studies suggest that combining polygenic risk scoring with commonly used CV risk assessment tools, such as SCORE2, improves the ability to identify individuals at risk of CV conditions, particularly in groups that are generally considered lower risk, such as younger people and women.2 This more robust risk assessment may lead not only to the recruitment of patients with higher relevance to the trial, but also the enrolment of a potentially more diverse and representative trial cohort.
Ensuring a Consistent Knowledge Base
Conducting a CVOT consistently across all trial sites, particularly international ones, helps minimise confounding variables and supports the validity of the trial’s findings. As a result, a key concern is ensuring that investigators have the knowledge and resources to carry out trials with consistency across all sites.
A key method of doing so is to select investigators from diverse regions where the disease in question is prevalent. Additionally, for conditions that may be harder to diagnose, sponsors should be certain to provide investigators with objective eligibility criteria that are applicable across regions to avoid the inclusion of patients with milder cases of the disease, or without the disease at all.






















