I highly recommend you to take a look at this article published in American Heart Journal last week(Feb, 2015). The authors identified 11 class 1A(means the best evidence) in STEMI or UA/NSTEMI and they followed them form clinical trial publication til meaningful application into clinical practice. It took 16 years for clinician to apply those evidence into practice.
For example evidence for ASA published in 1988 and took 2 years to come into guideline but it took 14 years till 2004 that we give 90% of our patients Aspirin for STEMI, UA/NSTEMI.
Does it make sense to you?