The trail only measure the outcome at 28days. To go beyond that, someone has to do the checking and recording but it does not even count as a data point for the trail. So who will be doing it? It just does not make sense for them to even keep track of those patients after 28 days. As a matter of fact, if you wait long enough, both arms will have a death rate of 100%. I remember my prof mentioned that if a student is 1 second late for the class, he is actually not late because it is only 1 second. But then the study who is 2 second late can not be late because he is only 1second later than the dude who is 1 second late. Base on this logic, no student will ever be late. And base on this same logic, if you change the trial by counting death after 28 days then you should count all the way to eternity.