Cardiology papers that have changed practice

Like we did for diabetes, we're hoping to include a section on papers that have changed practice in the BMJ Guide to Cardiology ebook.  Please add papers you would like to nominate for inclusion in the ebook on this thread. Please also state how the papers have changed practice in as much detail as possible.
Source: Doc2Doc BMJ Cardiology - Category: Cardiology Authors: Source Type: forums