Randomized surgical clinical trials for treatment of coronary artery disease.

The impact of randomized clinical trials of surgical therapy for treatment of coronary artery disease is evaluated. Trials are reviewed leading to the following suggestions: 1. Large multicenter trials have a major impact on clinical practice; 2. Small trials have less impact; 3. Findings in agreement with current practice are accepted enthusiastically; 4. Findings disagreeing with current practice are met very critically; and 5. Surgical trials have special problems because of a great variability between clinics, the potential of uneven learning curves, and potential "cross-over" from medical to surgical therapy.