Findings: Our goal is to enroll and follow a total of 700 patients over 5 years of recruitment. To date, 16 sites have enrolled a total of 502 patients into the study, 251 in the "survivor" cohort, 24 in the "inception" cohort, and 227 in the "control" cohort. There have been 66 reported deaths and 54 hemorrhagic events, 23 of which have been confirmed as major bleeds by the adjudication committee. The cohort to date has accumulated a total of 824 person-years of observation.