Blood Transfusion in Cardiac Surgery does increase the Risk of 5-Year Mortality: Results from a Contemporary Series of 1714 Propensity-Matched Patients
BACKGROUND:
Studies have found that cardiac surgery patients
receiving blood transfusions are at risk for increased mortality during
the first year after surgery, but risk appears to decrease after the
first year. This study compared 5-year mortality in a propensity-matched
cohort of cardiac surgery patients.
STUDY DESIGN AND METHODS:
Between
July 1, 2004, and June 30, 2011, 3516 patients had cardiac surgery with
1920 (54.6%) requiring blood transfusion. Propensity matching based on
22 baseline characteristics yielded two balanced groups (blood
transfusion group [BTG] and nontransfused control group [NCG]) of 857
patients (1714 in total). The type and number of blood products were
compared in the BTG.
RESULTS:
Operative mortality was
higher in BTG versus NCG (2.3% vs. 0.4%; p < 0.0001). Kaplan-Meier
analysis of 5-year survival demonstrated no difference between groups in
the first 2 years (BTG 96.3% and 93.0% vs. NCG 96.4% and 93.9%,
respectively). There was a significant divergence during Years 3 to 5
(BTG 82.0% vs. NCG 89.3% at 5 years; p < 0.007). Five-year survival
was significantly lower in patients who received at least 2 units of
blood (79.6% vs. 88.0%; p < 0.0001). In multivariate Cox regression
analyses, transfusion was independently associated with increased risk
for 5-year mortality. Patients receiving cryoprecipitate products had a
twofold mortality risk increase (adjusted hazard ratio, 2.106;
p = 0.002).
CONCLUSION:
Blood transfusion, specifically
cryoprecipitates, was independently associated with increased 5-year
mortality. Transfusion during cardiac surgery should be limited to
patients who are in critical need of blood products.
