Postoperative costs associated with outcomes after cardiac surgery with extracorporeal circulation: role of antithrombin levels

Abstract

Objective: To study the impact on postoperative costs of a patient's antithrombin levels associated with outcomes after cardiac surgery with extracorporeal circulation.

Design: An analytic decision model was designed to estimate costs and clinical outcomes after cardiac surgery in a typical patient with low antithrombin levels (<63.7%) compared with a patient with normal antithrombin levels (≥63.7%). The data used in the model were obtained from a literature review and subsequently validated by a panel of experts in cardiothoracic anesthesiology.

Setting: Multi-institutional (14 Spanish hospitals).

Participants: Consultant anesthesiologists.

Measurements and main results: A sensitivity analysis of extreme scenarios was carried out to assess the impact of the major variables in the model results. The average cost per patient was €18,772 for a typical patient with low antithrombin levels and €13,881 for a typical patient with normal antithrombin levels. The difference in cost was due mainly to the longer hospital stay of a patient with low antithrombin levels compared with a patient with normal levels (13 v 10 days, respectively, representing a €4,596 higher cost) rather than to costs related to the management of postoperative complications (€215, mostly owing to transfusions). Sensitivity analysis showed a high variability range of approximately ±55% of the base case cost between the minimum and maximum scenarios, with the hospital stay contributing more significantly to the variation.

Conclusions: Based on this analytic decision model, there could be a marked increase in the postoperative costs of patients with low antithrombin activity levels at the end of cardiac surgery, mainly ascribed to a longer hospitalization.