Introduction: Given changes in trial recruitment and advances in therapy for HF we evaluated if patient characteristics and their outcomes in contemporary HF randomized controlled trials (RCTs) have changed over the years.
Methods: We conducted a systematic review of HF RCTs with >250 subjects from 8 high impact-factor journals from 1986-2014. We excluded device trials and trials specific to HF with preserved ejection fraction. We examined the demographics, use of medications, and predicted and actual events rates.
Results: Earlier trials (prior to 2003) tended to have a longer follow up. Subjects in these trials were younger (63.5 yr v 64.0 yr), less likely to be male (74.5% v 78.3%), and more likely to be Caucasian (90.3% v 78.6%). Ejections fractions were similar. Subjects in earlier trials had a lower prevalence of myocardial infarction (42.7% v 64.1%), hypertension (50.2% v 69.5%), diabetes mellitus (24.9% v 35.0%), and atrial fibrillation (17.6% v 28.1%). They were also less likely to be on ACE-i/ARB (70% v 90.2%), beta blockers (50.1% v 86.5%), and spironolactone (11.8% v 45.8%), and more likely to be on digoxin (64.6% v 28.4%) or anti-arrhythmic (16.8% v 14.2%) medication. Diuretic use was similar. Predicted mortality rates in early trials ranged from 5-38% (median 12), and from 11-18% (median 13.5) in later trials. Actual event rates were reported in a non-uniform manner but when considering trials between 1-4 years in duration, all-cause mortality ranged from 9.1-44.1% (median 29.3) in early trials and 10.3-18.4% (median 15.1) in later trials (table).
Conclusion: Our systematic review found that the baseline characteristics of enrolled subjects in HF trials have changed significantly over the last 30 years. Minority participation is improving but not optimal and women remain under-represented. With the evolving therapies for HF mortality rates have fallen.