Enrollment of Older Patients, Women, and Racial/Ethnic Minority Groups in Contemporary Acute Coronary Syndrome Clinical Trials: A Systematic Review.

Although age, sex, and race/ethnicity are important factors when generalizing the findings of clinical trials to routine practice, trends in the representation of these groups in contemporary acute coronary syndrome (ACS) trials are not well defined. To characterize the representation of older patients, women, and racial/ ethnic minorities in ACS randomized trials. A systemic search was conducted of ACS trials published in 8 major medical journals between January 2001 and December 2018. Overall, 1 067 520 patients from 460 trials were included. Findings were compared with epidemiologic studies of patients with ACS. The median number of participants per trial was 711 (interquartile range, 324-2163) and the median number of sites per trial was 21 (interquartile range, 5-73). Overall, 207 trials (45.0%) studied drug therapy, and 210 (45.7%) evaluated procedural interventions. The mean (SD) age of trial participants was 62.9 (10.7) years and increased from 62.3 (11.2) years in 2001-2006 to 64.0 (10.4) years in 2013-2018 (P = .01). The corresponding mean (SD) age was 66.4 (14.8) years in US epidemiologic studies and 70.0 (13.5) years in European epidemiologic studies. The overall proportion of women enrolled was 26.8% and decreased over time, from 27.8% in 2001-2006 to 24.9% in 2013-2018 (P = .21 for trend). The corresponding weighted proportions of women were 38.0% in US epidemiologic studies and 32.0% in European studies. The distribution of racial/ethnic groups was reported in only 99 trials (21.5%). In trials with reported data, 15.0% of the trial participants were nonwhite, which increased from 12.0% in 2001-2006 to 14.0% in 2013-2018. Black patients represented 3.7% of all patients during the entire study time frame, Asian patients represented 9.6%, and Hispanic patients represented 7.8%. Trends in the representation of black patients remained unchanged from 2001-2006 (5.2%) to 2013-2018 (4.9%), while the enrollment of Asian and Hispanic patients increased from 2001-2006 to 2013-2018 (from 1.9% to 10.8% for Asian patients and from 5.4% to 14.5% for Hispanic patients). Older patients and women are underrepresented in contemporary ACS trials compared with epidemiologic studies. Over time, there has been modest improvement in the representation of older patients but not women patients. More than three-quarters of trials did not report race/ethnicity data, with available data suggesting a modest increase in the enrollment of nonwhite patients owing to the enrollment of Asian and Hispanic patients. Enrollment of black patients remained low over time.