Credit: University of Ottawa
Heart Institute
VANCOUVER—In a large study, heart surgery patients who received recently donated blood had significantly fewer post-operative complications than those who received blood stored for more than 2 weeks.
Patients who received newer blood had a lower rate of mortality, infection, and renal failure.
They were also less likely to require prolonged ventilation or re-exploration for bleeding.
Ansar Hassan, MD, PhD, of Saint John Regional Hospital in New Brunswick, Canada, and his colleagues presented these results at the Canadian Cardiovascular Congress as abstract 562.
The researchers examined records at the New Brunswick Heart Centre in Saint John for non-emergency heart surgeries performed from January 2005 to September 2013 on patients who received red blood cells during or after surgery and who stayed in the hospital less than 30 days.
Of 2015 patients, slightly more than half (n=1052) received only blood that was donated within 14 days of the transfusion. The rest of the patients received some or only blood that was donated more than 14 days before transfusion. Canadian protocols allow blood to be stored and used up to 6 weeks after donation.
Patients who received newer blood were more likely to be female, have unstable angina, to have undergone isolated coronary artery bypass graft or valve surgery, to have experienced shorter bypass and cross-clamp times, and to have left the operating room on inotropes.
After surgery, patients who received newer blood had a lower rate of mortality (1.7% vs 3.3%, P=0.02), infection (3.2% vs 5.4%, P=0.02), atrial fibrillation (43.8% vs 47.3%, P=0.12), and renal failure (12.8% vs 17.7%, P=0.0003).
In addition, they were less likely to require ventilation for more than 24 hours (3% vs 7.7%, P<0.0001) or re-exploration for bleeding (1.5% vs 3.1%, P=0.02).
After the researchers adjusted for differences in baseline and intra-operative characteristics, receiving newer blood was associated with a significant reduction in a composite of the aforementioned outcomes (odds ratio=0.79, P=0.01).
“The findings show that we need to pay attention to the age of the blood we give cardiac surgery patients,” Dr Hassan said. “Perhaps more importantly, we need new studies to determine what is driving this relationship between the age of blood and the outcomes we are seeing.”
Dr Hassan noted that previous studies have reached contradictory conclusions on this subject, which was a reason this study was conducted.
