Among 12,887 patients who received study medication , 11,117 ( 86.3 % ) received clopidogrel before randomization , of whom 38.5 % stopped later in the trial ( median time to stoppage 200 days with placebo ; interquartile range [ IQR ] 14-367 ) ( 186 days with vorapaxar ; IQR 17-366 ) .