Autologous blood transfusion in elective cardiac valve operations.

BACKGROUND AND AIM OF STUDY

The aim of this study was to detect any outcome differences between patients who donated autologous blood versus nondonors undergoing nonemergent cardiac valve surgery. Of further interest was whether autologous donors required less allogeneic blood products overall than patients who did not donate.

METHODS

We conducted a nested case-control study in which data were collected prospectively on 225 variables. Cases underwent nonemergent, cardiac valve surgery and donated autologous blood products (n = 40). Controls also had nonemergent, cardiac valve surgery but did not donate autologous blood products (n = 120). Cases were matched to controls 1:3 on age (+/-3 years), gender, and New York Heart Association Functional Classification. We controlled for 12 potential confounding variables and examined 17 outcomes of interest. To generate the unadjusted risks of each outcome, chi-square and t-tests were performed comparing cases and controls to each outcome of interest. Then logistic regression analysis investigated the adjusted risk between cases and controls and for the outcomes of interest, each controlling for the potential confounding variables.

RESULTS

There were no significant differences between the cases and controls for 11 of the 12 possible confounding variables. Controls had significantly more chronic obstructive pulmonary disorder. There were no significant differences between cases and controls for 13 of the 17 outcomes of interest. Autologous blood donors received more total packed red blood cells (PRBCs) (p = 0.0373) and more total fresh frozen plasma than controls (p = 0.0002). Fewer autologous blood donors required allogeneic packed red blood cell transfusion (p = 0.0134), and the total length of stay was shorter for autologous donors (p = 0.0782).

CONCLUSION

Four of the 17 outcomes of interest were different for patients who donated autologous blood versus those who did not. Our experience demonstrated that elective cardiac valve surgery can safely reduce (by 18.3%) the need for allogeneic PRBCs by utilizing preoperative autologous blood donation.