This study was designed to systematically quantitate and determine the cause of a marked discrepancy that we noted in the postprocedural hematocrit of patients undergoing coronary stent placement, and in others undergoing balloon angioplasty despite similar procedural blood loss. We found that dextran 40, when administered after coronary stent placement, results in a marked decrease in hematocrit within 24 hours, which reverts to baseline at 48 hours, and does not require extensive workup;of the patient.