The PROTECT trial published in NEJM

Neil Orford on 23-03-2011

The PROTECT trial is another incredible ANZICS CTG effort, in conjunction with the Canadian CTG. This 3764 participant, db, mulitcentre, international, RCT, compared dalteparin to unfractionated heparin in adult ICU patients (exclusions included orthopaedic, neurosurgery, major trauma) with proximal DVT detected by twice weekly compression ultrasound the primary outcome. The interesting points are; 1. No difference in primary outcome, with overall incidence of proximal DVT 5.6% 2. Most VTE occurs in the ICU, not the ward 3. A reduction in PE in the dalteparin group (HR 0.51, 95% CI 0.30-.88)NNT=100. PE was sought on clinical suspicion, not screening, so it is possible that some bias exists, although the mechanism by which 1 group would be tested more for PE is unclear 4. No difference in bleeding 5. No difference in HITs, although the per-protocol analysis reported a decrease in the dalteparin group (HR 0.27, 95% CI 0.08-.98). This should be interpreted with caution Questions 1. Is the reduction in PE and possibly thrombocytopenia, combined with safety profile, enough to justify switch to LMWH? 2. Does it simply come down to a cost-benefit analysis?