First clinical application of the Medos-HIA ventricular support system: monitoring of the thrombotic risk by means of the biomarker prothrombin fragment F1 + 2 and scanning electron microscopy evaluation.

Background: The medos-HIA ventricular support system was designed as an artificial heart assist device for intractable heart failure to act as a bridge for transplantation or recovery. The aim of this study is to report on the first clinical application of the system and to evaluate the thrombotic risk with the use of the biomarker prothrombin fragment F1 + 2 and scanning electron microscopy of the blood contacting surface.
Methods and Results: This device worked without any failure for 462 hours, and a sufficient output of 5.2 to 6 L was observed. No activation of the procoagulatory system occurred during pumping until the occurrence of the septicemia. Preseptic F1 + 2 levels were normal, at about 1 nmol/L. The blood contacting surfaces of the pump and the polyurethane valves were examined by means of scanning electron microscopy, and the surfaces were found to have smooth fibrin layers with no thrombogenic deposits. This fibrin layer is considered to prevent thrombotic adhesions, thereby minimizing the risk of thromboembolic complications. Post mortem examinations after pneumonia with septic shock showed no thrombus formation in this support system and around the inserted cannulas.
Conclusions: The low risk for thromboembolic complications, no measurable activation of the coagulation system, and the excellent surface characteristics encourage further use of this inexpensive working device.