Early postoperative outcomes and blood product utilization in adult cardiac surgery: the post-aprotinin era

Abstract

Background: Aprotinin was a commonly used pharmacological agent for homeostasis in cardiac surgery but was discontinued, resulting in the extensive use of lysine analogues. This study tested the hypothesis that early postoperative adverse events and blood product utilization would affected in this post-aprotinin era.

Methods and results: Adult patients (n=781) undergoing coronary artery bypass, valve replacement, or both from November 1, 2005, to October 31, 2008, at a single institution were included. Multiple logistic regression modeling and propensity scoring were performed on 29 preoperative and intraoperative variables in patients receiving aprotinin (n=325) or lysine analogues (n=456). The propensity-adjusted relative risk (RR) for the intraoperative use of packed red blood cells (RR, 0.75; 95% confidence interval [CI], 0.57 to 0.99), fresh frozen plasma (RR, 0.37; 95% CI, 0.21 to 0.64), and cryoprecipitate (RR:0.06; 95% CI, 0.02 to 0.22) were lower in the aprotinin versus lysine analog group (all P<0.05). The risk for mortality (RR, 0.53; 95% CI, 0.16 to 1.79) and neurological events (RR, 0.87; 95% CI, 0.35 to 2.18) remained similar between groups, whereas a trend for reduced risk for renal dysfunction was observed in the aprotinin group.

Conclusions: In the post-aprotinin era, with the exclusive use of lysine analogues, the relative risk of early postoperative outcomes such as mortality and renal dysfunction have not improved, but the risk for the intraoperative use of blood products has increased. Thus, improvements in early postoperative outcomes have not been realized with the discontinued use of aprotinin, but rather increased blood product use has occurred with the attendant costs and risks inherent with this strategy.

Figure 1

The propensity adjusted relative risk blood product utilization in the early intra-operative/post-operative period (<24 hours) and the late post-operative period (>24 hours) in the aprotinin group versus the lysine analogue group. The relative risk for the use of rVlla was computed for the entire intra-operative/post-operative course. The risk for early utilization of red blood cells, fresh frozen plasma and cryoprecipitate was significantly lower in the aprotinin group (p<0.05). In the late post-operative period, the risk of blood product utilization was equivalent between the aprotinin group and the lysine analogue group, with one notable exception. The propensity adjusted risk for the use of rVlla was substantially lower in the aprotinin group (p<0.05).

Figure 2

The propensity adjusted relative risk for early post-operative adverse events in the aprotinin group versus the lysine analogue group. Overall, the propensity adjusted analysis failed to identify any risk reduction in significant peri-operative adverse events in the post-aprotinin era. Indeed, there was a trend for a reduction in the risk of respiratory in the aprotinin group (p=0.06). Although the propensity adjusted risk of renal failure was reduced in the aprotinin group, this was not significant (p=0.13).