Influence of clinical trial enrollment on the quality of care and outcomes for patients with non-ST-segment elevation acute coronary syndromes

Background: Clinical trials provide evidence that is formulated into recommendations for practice guidelines, but it remains uncertain whether patients enrolled in trials are similar to those treated in routine practice and whether trial enrollment influences inhospital treatments and outcomes. Methods: Using data from the CRUSADE quality improvement initiative, we evaluated predictors of trial enrollment, treatment patterns, and clinical outcomes among high-risk patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS) who were and were not enrolled in a clinical trial during hospitalization. Results: Among 55 172 high-risk patients presenting with NSTE ACS at 443 US hospitals, 1397 (2.5%) patients were enrolled in a clinical trial during index hospitalization. Significant predictors of trial enrollment included male sex, lack of renal insufficiency, and absence of congestive heart failure on presentation. Acute (<24 hours) and discharge secondary prevention interventions recommended by the American College of Cardiology/American Heart Association guidelines for NSTE ACS were used more commonly in patients enrolled in clinical trials. Cardiac catheterization (84.5% vs 65.8%, P <. 0001), percutaneous coronary intervention (48.2% vs 36.3%, P <. 0001), and bypass surgery (19.1% vs 11.3%, P <. 0001) were also performed more frequently in trial patients. The adjusted risk of inhospital mortality was similar in trial versus nontrial patients (odds ratio 0.86, 95% CI 0.60-1.24). Conclusions: Patients with NSTE ACS participating in clinical trials are more likely to receive beneficial therapies and interventions throughout hospitalization, but preferential recruitment of patients with lower-risk features may limit the external validity of trial results.