First experiences with a novel magnetically suspended axial flow left ventricular assist device

Axial flow pumps have gained increased acceptance since their first clinical use in 1998. The present report summarizes the clinical experience with patients treated for severe cardiogenic shock for the first time with a newly developed axial flow pump with magnetically levitated bearings.

The axial flow pump Incor was implanted in 24 patients between June 2002 and June 2003. All except one patient were men. In 16 patients dilative cardiomyopathy, in seven ischemic and in one restrictive cardiomypathy had been diagnosed. All patients presented with catecholamine-dependent end-stage heart failure, seven of them were on an artificial ventilator and three were dependent on intraaortic balloon pump support. All patients suffered from organ dysfunction resulting from low cardiac output.

There were no perioperative deaths. The 30-day mortality rate was 8% (n = 2); 79% ( n = 19) of patients reached a condition to be discharged home. The cumulative time on the device is 6.9 years; the longest individual time up to July 1, 2003 is 12.6 months. There were no structural defects or failures of the system. In one case the controller had to be exchanged because of intermittent malfunction. Cardiac output ranged between 4 and 6 l in all instances and there were no cases of infection of the drive-line or the system. Hemolysis was present initially but was not detectable in the later course. There were three instances of transient ischemic attacks. Two patients developed late cardiac tamponade with re-opening of the chest after 9 and 14 days. In one patient persistent gastrointestinal bleeding required re-hospitalization and transfusion therapy. Two patients were weaned from the device after 6 and 7 months of support, respectively.

The preliminary clinical experience with Incor is promising. The flow is sufficient for recovery from multiorgan failure and the pump allows long-term hemolysis-free support. The concept of magnetically levitated bearings has proven to be durable and reliable. In the case that the heart may recover through unloading, weaning from the pump is possible.