Patients who received blood platelet transfusions during coronary bypass surgery were more likely to have prolonged hospital stays, longer surgeries, more bleeding and higher risk of infection, stroke and death, according to an international study led by the Virginia Commonwealth University Medical Center.
The findings, published in the August issue of Transfusion, the official journal of the American Association of Blood Banks, contribute to increasingly scientific evidence that blood transfusions do not always improve outcomes from surgery.
"Although this analysis cannot prove that platelet infusions caused the increases in adverse events examined, the data are sobering and should be taken into account when determining the risk-benefit ratio of platelet transfusion therapy," says Dr. Bruce D. Spiess, professor of anesthesiology and lead author on the article. "Prophylactic platelet transfusion appears from this study to increase the risk for serious adverse outcomes in coronary artery bypass graft patients."
The study examined data collected during six randomized, double-blinded Phase III clinical trials conducted from January 1990 through May 1995 at 37 medical centers in the United States, Denmark and Israel for licensure by the Food and Drug Administration of aprotinin, a drug sold by Bayer Corp. under the trade name Trasylol to control bleeding during surgery and avoid the need for transfusions. Data from patients in a pilot study also were included.
Of the 1,720 adult patients analyzed, 284 patients (14.4 percent of the total) received blood platelet transfusions during coronary artery bypass graft surgery, which is a common procedure used to improve blood flow and alleviate chest pains. In coronary artery surgery, doctors remove a clear vein or artery from a leg, arm or the chest and use it to detour blood flow around a blocked artery. Because about 20 percent of coronary bypass patients suffer abnormal bleeding, blood platelets often are given after surgery to prevent or treat bleeding.
The retrospective analysis showed that death was greater than five times more likely to occur in patients receiving platelet transfusions, and stroke was at least three times more likely to occur compared with patients who did not receive transfusions. In addition:
- The operation was almost one hour longer for patients receiving a platelet transfusion than for those not receiving one.
- Almost 20 percent of patients who received platelet transfusions returned to surgery for re-exploration compared with a 2 percent re-operation rate for those who did not receive platelets.
- The amount of bleeding and length of time in the hospital were greater in the group who received transfusions.
"Blood transfusions may do more harm than good in virtually every instance except trauma," says Spiess. "Blood transfusions increase the risk of pneumonia, infections, heart attacks and strokes. Patients who don't have transfusions often do better."