Lessons learned from the first fully magnetically levitated centrifugal LVAD trial in the United States: the DuraHeart trial.

BACKGROUND

The DuraHeart is a continuous centrifugal-flow left ventricular assist device that uses active magnetic levitation for impeller positioning designed for improved hemocompatibility and durability. This study reviews the results of the US trial with specific attention to hemolysis, thrombotic complications, and pump failure.

METHODS

The US SUSTAIN trial was a multicenter, prospective, single-arm observational study in advanced heart failure patients listed for transplantation. Follow-up was complete in 100% of the patients at 6 months.

RESULTS

Sixty-three patients were enrolled at 23 centers. Forty-six patients (73%) reached the primary end points of survival to transplantation, alive on the original device at 180 days and listed for transplantation, or explant for recovery. Median duration of support was 267 days (range, 10 to 952 days) with a total support time of 46 patient-years. There was no clinical hemolysis reported during the study. Mean lactate dehydrogenase values peaked at day 4 and significantly decreased during support (435±236 U/L and 297±142 U/L on day 3 and day 180, respectively). There were no cases of pump thrombosis reported, and 3 cases of pump thrombus "in transit" (0.06 events/patient-year) were observed. There were 6 (10%) cases of magnetic levitation system failure, all secondary to cable wire fractures (0.12 events/patient-year). All patients were hemodynamically stable with the backup hydrodynamic mode. Major adverse events included gastrointestinal bleeding (0.52 events/patient-year), ischemic and hemorrhagic strokes (0.17 events/patient-year and 0.09 events/patient-year, respectively), and driveline infections (0.67 events/patient-year).

CONCLUSIONS

The DuraHeart demonstrated good hemocompatibility; however, the reliability of full magnetic levitation systems should be a high priority in future pump designs.