Representation of Older Adults and Women in Randomized Trials of Non-Invasive Imaging for Chest Pain

Non-invasive imaging is widely used both for initial diagnosis and to guide management of ischemic heart disease (IHD). Older adults and women with IHD may have different responses to imaging as well as to treatments and outcomes that follow compared with younger adults and men. We aimed to study the representation of older adults and women in randomized controlled trials (RCT) of non-invasive imaging among patients with acute and stable chest pain.

We conducted a systematic search to identify RCTs evaluating non-invasive, imaging-guided diagnosis and management for IHD that were published before September 1, 2023. Participation-to-Prevalence Ratio (PPR) was estimated for women and age subgroups of <65, 65-74, ≥75 years. PPR of <0.8, 0.8-1.2, and >1.2 indicated underrepresentation, appropriate representation, and overrepresentation, respectively.

Among 53 RCTs, sex and age breakdown were available in 53 (n=55,893) and 21 trials (n=35,503), respectively. The median age across all trials was 57.4 years [IQR: 55.0- 60.2]. Participants aged <65 years were overrepresented with a median PPR 2.13 [IQR: 1.73- 2.43], while those aged 65-74 years and ≥75 years were underrepresented with median PPRs of 0.74 [IQR: 0.56-0.83] and 0.21 [IQR: 0.11-0.33], respectively. Women were adequately represented with a median PPR of 1.2 [1.06-1.32].

While women were appropriately represented, adults 65 years or older, especially those ≥75 years, were under-represented in these trials. Future RCTs on non-invasive imaging should target enrollment of older adults to ensure generalizability of results to this growing population.

In a systematic review of 53 randomized controlled trials of non-invasive imaging for chest pain published before September 1, 2023 (n=55,893 participants), adults aged 65 years and older, especially those aged 75 years and above, were significantly underrepresented, whereas women had representation proportional to prevalence estimates. These findings highlight an urgent need to increase enrollment of older adults in future imaging trials to ensure broader applicability and relevance of study results.