Heparin-coated adult ECMO vs. ventricular assist devices: a decision analysis modeling approach

Postcardiotomy failure requiring ventricular assist occurs in about 1% of adult patients undergoing cardiac surgical procedures. One method of support is a short-term ventricular assist device. This incurs the cost of the device, which is substantial, and allows for reduced anticoagulation in the first 24 hours. Another option is a heparin-coated extracorporeal membrane oxygenation (ECMO) circuit. This also allows for reduced anticoagulation and can support the lungs if necessary. The use of a heparin-coated ECMO circuit requires 24-hour monitoring, but the cost of disposables is considerably less than the cost of ventricular assist devices. This decision analysis uses a Markov model to evaluate the relative outcomes and costs associated with selection between these modalities of support. Data from the past 5 years of patients who received postcardiotomy support will be used to develop the Markov model. The hypothesis is that supporting the patient on heparin-coated ECMO before instituting ventricular assistance will reduce cost and allocate resources in a more cost-effective manner. The model was used to determine the optimal economic time for initiation of ventricular assist devices in postcardiotomy patients. The total costs associated with support begin to level out between postoperative days 6 and 10 using an Abiomed BVS5000 ventricular assist device. The largest decline in costs occurs after postoperative day 3. This model suggests that patients should be supported on heparin-coated ECMO for 2-3 days to evaluate their potential for recovery before instituting more expensive ventricular assist devices.