Hetastarch and Bleeding Complications After Off-Pump Coronary Bypass Surgery
Status:
Completed
Trial end date:
2005-08-01
Target enrollment:
Participant gender:
Summary
There has been continuing debate about whether use of hetastarch for volume replacement in
coronary artery bypass surgery [CABG] increases the risk of postoperative bleeding. A recent
meta-analysis of hetastarch use in on-pump CABG concluded that use of hetastarch in these
procedures is associated with increased risk, but the safety of hetastarch use in off-pump
procedures remains unresolved.
We designed a double-blinded randomized clinical trial to investigate this question. The
study was designed as an equivalence trial. Statistical power calculations were performed
taking this into consideration. Sealed assignments from a block randomization table developed
prior nto initiation of the trial were unsealed in the operating room. These were used to
assign patients scheduled for off-pump CABG to receive either 1 L of hetastarch or 1 L of
albumin as part of intraoperative volume replacement. Albumin was used for all subsequent
intraoperative and postoperative fluid replacement.
The rate of postoperative bleeding was assessed prospectively by monitoring hourly chest tube
drainage and number of units of blood products transfused postoperatively in the Intensive
Care Unit. Risk was assessed by a Data Safety Monitoring Committee (DSMC) established for
this trial. The SAMC was scheduled per protocol to meet after the first 15 subjects (both
groups combined) had 1000cc or more of chest tube drainage in the first 12 hours
postoperative, and then subsequently either after 15 additional bleeds of this volume or
following a schedule set at the discretion of the DSMC.
The trial was continued until 156 patients had been recruited. At that time, 78 participants
each had been assigned to the hetastarch and albumin groups. DSMC review at that time
determined that use of hetastarch is associated with a risk of postoperative bleeding which
is greater than the risk associated with use of albumin and the DSMC accordingly halted the
trial.