Trial patients may not reflect larger MI population

Participants enrolled in cardiovascular clinical trials may be a poor representation of patients with MI, according to an analysis published Aug. 27 in JAMA. Researchers found enrollees generally to be healthier, younger and have a better prognosis than eligible nonparticipants.

Jacob A. Udell, MD, MPH, of Women’s College Hospital in Toronto, and colleagues used the National Cardiovascular Data Registry Acute Coronary Treatment and Interventions Outcomes Network Registry-Get With the Guidelines to compare patients enrolled and not enrolled in randomized clinical trials. They questioned whether participants represented MI patients in contemporary practice.

Their study included 141,135 registry participants from 466 facilities for whom data was submitted between July 1, 2008 and March 31, 2011. Of those patients, only 2.8 percent participated in trials although 68 percent were eligible based on inclusion/exclusion criteria.

Trial participants were younger, with a median age of 60 vs. 63 for eligible nonparticipants and 67 for ineligible patients. They were less likely to have a history of MI, coronary revascularization, stroke or congestive heart failure than the other two groups.

Enrollees had a lower median risk score for in-hospital mortality than eligible participants and ineligible patients as well as lower rates for in-hospital mortality and adverse events.   

Udell et al also found that trial participation waned over the years. In 2008, 5.2 percent of the patients were in trials vs. 4.4 percent in 2009, 3.8 percent in 2010 and 3.4 percent in 2011.

“Efforts to improve trial participation are needed to enhance generalizability of results,” they proposed. “Nesting trials within existing registries may help meet this goal.”