“…2,9,10 It seems obvious that well-known influencing factors of the ACT measurements, such as diluted coagulation factors, hypothermia, low platelet count, or impaired platelet function, 7,8 might differently affect the 2 devices, leading to variable test results, especially with high heparin dosages 11 or prolonged CPB. 12 Technical differences between the ACT devices support the conclusion that Hemochron and iSTAT are not interchangeable. 9 They might further explain the variable behavior of ACT changes during CPB as reported in the present study.…”