Sunday, August 17, 2008

Factor VII Curbs Bleeding in Non-Hemophiliac Trauma, Surgical Patients

Use of recombinant activated factor VII (rFVIIa) reduces the need for blood transfusion in patients without hemophilia and may also reduce mortality, according to pooled data from randomized placebo-controlled trials involving more than 3000 participants, Canadian researchers report.
"I had found it to be effective in some combat situations in Afghanistan," senior investigator Dr. Vivian C. McAlister told Reuters Health. "I was therefore dismayed when I noticed that rFVIIa was being dismissed by some influential physicians as being expensive, dangerous and ineffective."That report, by US Federal Drug Administration (FDA) physicians, he added, "was flawed because it only looked at adverse events that had been reported."To gain a more balanced picture, Dr. McAlister and colleagues at the University of Western Ontario, London conducted a meta-analysis of 22 trials involving 3184 patients without hemophilia. Trial settings included trauma, variceal bleeding, cardiac surgery, liver transplantation and other surgeries. The team's findings appear in the July issue of the Annals of Surgery."When we combined results," continued Dr. McAlister, "we found rFVIIa to be effective in controlling hemorrhage and to save lives without increasing the risk of venous thrombosis."Specifically, compared to placebo, patients receiving rFVIIa were less likely to require additional blood transfusions (odds ratio, 0.54). Mortality was not increased and may have been reduced in patients receiving rFVIIa (OR, 0.88). The mortality reduction seemed more likely when the agent was given therapeutically, rather than prophylactically.There may have been a higher incidence of arterial thromboembolic events (OR, 1.50) but not venous thromboembolic events (OR, 0.76) in patient given rFVIIa, although the differences did not reach statistical significance."There was an increased rate of heart attack in patients who received rFVIIa," Dr. McAlister pointed out, "but it is not known if this was due to the stress which they had survived or related to rFVIIa itself.""Subgroup analysis," he concluded, "suggested the most effective way to give rFVIIa is in lower doses to stop, rather than to prevent, bleeding."