As seen in the Figure, a total of 35 out of the 500 patients in the RACE trial[59] had a thrombolic event: 5.5% in the rate control group, and 7.9% in the rhythm control group.  The higher number in the rhythm control group included 6 patients who had events after their warfarin was discontinued, and 68% of the patients who had a thrombolic event while on warfarin were found to have an INR level that was subtherapeutic.  Of interest, in 81% of patients who had a bleeding episode during this trial, the INR level was supratherapeutic (INR >3).

Rothman SA. Am J Med 2013; 126: 00-00.