Postoperative Costs Associated With Outcomes After Cardiac Surgery With Extracorporeal Circulation: Role of Antithrombin Levels

ObjectiveTo study the impact on postoperative costs of a patient's antithrombin levels associated with outcomes after cardiac surgery with extracorporeal circulation.DesignAn 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.SettingMulti-institutional (14 Spanish hospitals).ParticipantsConsultant anesthesiologists.Measurements and Main ResultsA 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.ConclusionsBased 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.