Risk factor analysis for bridge to transplantation with the CardioWest total artificial heart

Safety and efficacy studies of various mechanical circulatory support devices are important, but may not be strictly comparable. Lacking prospective randomized studies for different devices, we believe that comparison of risk factor analyses may give the surgeon a tool more powerful than current studies for matching a patient with an appropriate device. In this paper, we report risk factor profiles for bridge to transplantation with the CardioWest total artificial heart and summarize reports for other devices.

A multiinstitutional risk factor analysis of the CardioWest total artificial heart, as a bridge to transplantation in 81 patients, was conducted. Univariate analyses were performed on 43 preimplantation prognostic factors. From this group, eight factors were chosen for multivariate analysis. Our results were compared with all recent risk factor analyses for other devices.

Independent predictors for death at three intervals by multivariate analysis were as follows: "implant to transplant": history of smoking (odds ratio, 34); "implant to 30 days after transplant": history of smoking (odds ratio, 10.00), prothrombin time greater than 16 seconds (odds ratio, 4.76); and "implant to 1 year after transplant": prothrombin time greater than 16 seconds (odds ratio, 3.85). The major difference between this experience and multiple reported experiences with left ventricular assist devices is that for left ventricular assist devices, but not for the temporary CardioWest total artificial heart, right heart failure, high central venous pressure, and being on a ventilator (with or without sepsis) were independent predictors of mortality.

Risk factors for bridge to transplantation with the CardioWest total artificial heart are different from those reported for left ventricular assist devices. Recognition of these risk factor differences may facilitate appropriate device selection.