Conservative Versus Liberal Red Cell Transfusion in Myocardial Infarction Trial: The CRIT Pilot

The current standard of care for patients with heart attacks is to transfuse red blood cells
when the hematocrit (red blood cell count) drops below 30 percent. However, there is little
scientific basis for this current standard, and recent research has demonstrated that it is
safe to allow the hematocrit (red blood cell count) to drop significantly lower in severely
ill medical patients and in patients with heart disease undergoing major surgery. The
investigators therefore propose this pilot trial to begin to determine whether or not it is
safe to apply a more conservative blood transfusion strategy to patients with heart attacks.

In this study, patients who are within 72 hours of the onset of a heart attack and who are
anemic (have a low red blood cell count) will be randomly assigned to one of two transfusion
strategies while they are in the hospital: a liberal strategy of transfusing blood when the
hematocrit falls below 30 percent (the current standard) or a conservative strategy of
transfusing blood only when the hematocrit falls below 24 percent. It will then be
determined which group fares better over the next 30 days.

The plan is to enroll 92 patients in this pilot trial in order to allow the researchers to
plan for a much larger, definitive trial of this important question. It is anticipated that
the conservative transfusion strategy will be similar to the standard (liberal) strategy in
terms of patient outcomes.