Initial Clinical Experience with the HeartMate ® II Axial-Flow Left Ventricular Assist Device

The redesigned HeartMate ® II, an axial-flow left ventricular assist device, is simpler, smaller, and easier to operate than are pulsatile pumps. These design characteristics should make the HeartMate II more reliable and durable and broaden the eligible population base. We implanted the HeartMate II in 43 patients (average age, 42 yr). The indication for use was bridge-to-heart transplantation in 26 patients and destination therapy in 17. The average duration of device support was 258 days (range, 1–761 days), and cumula-tive duration, more than 31 patient-years. Hemodynamic function improved in all patients during support. By 48 hours after implantation, the mean cardiac index had increased from 1.9 ± 0.27 L/(min⋅m2) (baseline) to 3.5 ± 0.8 L/(min⋅m2), and the pulmonary capillary wedge pressure had decreased from 24.8 ± 11 mmHg to 18.5 ± 5.3 mmHg. Of the 43 patients, 35 were discharged from the hospital. Support is ongoing in 27 patients (longest duration,>700 days). Nine patients died during support. Four patients had sufficient heart recovery to undergo pump explantation. Three patients underwent transplantation. One patient un-derwent device replacement after the pump driveline was fractured in a skateboarding accident; the device was removed in another patient because of a pump-pocket infection after 749 days of support. Of the 10 patients in whom the HeartMate II replaced a faile