WASHINGTON — Patients who received bivalirudin as their anticoagulant during percutaneous coronary intervention required fewer transfusions than did those treated with unfractionated heparin, based on a post hoc analysis of data from a study of 6,010 patients.
This effect appeared to protect against mortality during the subsequent year, Steven V. Manoukian, M.D., reported in a poster at a meeting sponsored by the Cardiovascular Research Institute at Washington Hospital Center.
“These are the first data to suggest that a difference in antithrombotic therapy can influence the transfusion rate. It is a way to reduce the risk from blood transfusions,” he said while presenting the poster. Results from prior studies showed that blood transfusions are an independent predictor of mortality in patients undergoing percutaneous coronary intervention (PCI), said Dr. Manoukian, director of interventional cardiology at Emory Crawford Long Hospital in Atlanta. The current findings confirmed this and further showed that patients treated with bivalirudin (Angiomax) faced a reduced risk because the regimen led to less blood loss than did the heparin regimen.
The data were collected in the Randomized Evaluation in PCI Linking Angiomax to Reduced Clinical Events (REPLACE)-2 trial, which compared two different anticoagulant regimens in 6,010 patients undergoing PCI. The results showed that treatment with bivalirudin plus provisional treatment with a glycoprotein IIb/IIIa inhibitor was not inferior to treatment with unfractionated heparin plus planned treatment with a glycoprotein IIb/IIIa inhibitor (JAMA 2003;289:853–63). The study was funded by the Medicines Co., which markets Angiomax. Dr. Manoukian has been a speaker for the company.
Overall, 126 patients received a blood transfusion during the first 30 days following PCI. The transfusion rate in patients treated with bivalirudin was 1.7%, compared with a 2.5% rate in those treated with heparin, a statistically significant difference.
In a post hoc analysis that compared the outcomes of patients who received transfusions with those who did not, the mortality rate 30 days after PCI was 6.3% among patients who received a transfusion and 0.2% among all other patients. Six months after PCI, cumulative mortality was 10.6% among patients who received a transfusion, compared with a 1.0% rate among those who didn't. After adjustment for baseline demographic differences, patients who received a transfusion were 5.67-fold more likely to die within 6 months, compared with patients who did not receive blood. At 1 year after PCI, mortality was 13.9% in the transfusion group and 1.9% in all other patients. After adjustment, patients who received blood had a 4.26-fold higher risk of death. Another notable feature of the increased mortality risk linked with transfusions was that the disparity persisted for a year after PCI.
It's unclear why transfusions were linked with an increased death risk. It may be that giving blood to people triggers an inflammatory or thrombotic reaction, Dr. Manoukian told this newspaper. It's also possible that the need for transfusion immediately following PCI is a surrogate marker for other adverse events during PCI that lead to an increased risk of death during the subsequent year.