Little is known about the proportion of hospitals in the United States that offer clinical trial enrollment opportunities and how patient outcomes differ between hospitals that do and do not participate in clinical trials.

In the nationwide Chest Pain–MI registry, we described the proportion of hospitals that enrolled patients with acute myocardial infarction (MI) in clinical trials from 2009 to 2014. Hospital-level adherence to every eligible MI performance measure was compared between hospitals that did and did not enroll patients in clinical trials. Using linked Medicare data, we also compared 1-year major adverse cardiovascular events (MACE: death, MI, heart failure, or stroke) among patients ≥65 years old treated at trial versus nontrial hospitals.

Among 766 hospitals, 430 (56.1%) enrolled ≥1 MI patient in a clinical trial during the study period, but the proportion of hospitals enrolling patients in clinical trials declined from 36.8% in 2009 to 26.6% in 2014. Complete adherence to performance measures was delivered to a greater proportion of patients at trial hospitals than nontrial hospitals (72.6% vs 64.9%, P < .001; adjusted OR 1.07, 95% CI 1.03-1.12). One-year MACE rates were also lower for trial hospitals (adjusted HR 0.96, 95% CI 0.93-0.99).

Hospitals are becoming less likely to engage in clinical trials for patients with MI. Patients admitted to hospitals that participated in clinical trials more often received guideline-adherent care and had better long-term outcomes.