Population
Patients undergoing cardiac surgery (39 studies, n= 180,074).
Intervention
Red blood cell (RBC) transfusion.
Comparison
No RBC transfusion.
Outcome
The meta-analysis identified 180,074 patients with follow-up data ranging from 1 to 15 years. The majority (61.2%) of patients underwent coronary artery bypass surgery. Perioperative blood transfusions were noted in 42.2% of patients and was associated with significantly higher early mortality (OR= 3.87). After a median of 6.4 years (range 1, 15), mortality remained significantly higher for those who received a perioperative transfusion (OR= 2.01). Pooled hazard ratio for long-term mortality was similar for patients who underwent coronary surgery compared to isolated valve surgery. Differences in long-term mortality for all comers remained true when corrected for early mortality and when only including propensity matched studies.