Randomized clinical trials are considered the gold standard for establishing evidence and, therefore, influencing practice, but some do not change what we do. Enormous amounts of money and energy are expended on clinical trials. Some are designed to justify what we already think we should do based on experimental and early observational studies and clinical experience. The trials of drug-eluting stents are examples of trials, not designed to change practice so much as to produce acceptable evidence to justify what we wanted to do anyway and so that the devices can be marketed for that purpose. There was never equipoise as to whether drug-eluting stents would result in less restenosis than bare metal ones. Of course, the short-lived concern about stent thrombosis caused a temporary selective use and, importantly, improvements in stents. Some trials are done to establish the value of new technology such as transcatheter aortic valve implantation (TAVI), or TAVR, for “replacement”, although nothing is replaced. The first trials enrolling inoperable subjects were perhaps necessary but painful. There was no equipoise between TAVI and medical therapy for these unfortunate patients randomized to medical therapy, but I suppose it had to be done. Of course, we never had a trial of surgery for appendicitis, yet practice changed when it became obvious that appendectomy worked. Subsequent trials of TAVI vs. surgery have changed practice dramatically.