Effects of Centrifugal, Axial, and Pulsatile Left Ventricular Assist Device Support on End-Organ Function in Heart Failure Patients

Abstract

Newer continuous-flow left ventricular assist devices (LVAD) have the advantage of smaller size and increased durability. Questions remain regarding the safety and effects of long-term nonpulsatile flow, despite some animal and human studies showing that end-organ function is well maintained with pulsatile or axial-flow devices. This study investigated whether centrifugal devices have similar effects on end-organ function. All patients who underwent LVAD implantation as bridge-to-transplant (BTT) therapy from January 2004 through May 2007 were reviewed. Excluded were patients on biventricular support, destination therapy, temporary support, and patients who died within 30 days after LVAD implantation. The centrifugal device was the VentrAssist (Ventracor Ltd, Sydney, Australia); axial, the HeartMate II; and pulsatile, the HeartMate XVE (Thoratec Corp, Pleasanton, CA). During the study, 10 VentrAssist, 30 HeartMate II, and 18 HeartMate XVE devices were implanted. Among the 3 groups, age, gender, weight, duration of LVAD support, and cause of heart failure were comparable. No significant differences were found between groups with respect to baseline renal function, hepatic function, or hematologic function. At 1 and 3 months of follow-up, renal and hepatic function either improved or remained within normal limits in all groups. Centrifugal, axial, and pulsatile LVADs all provide adequate circulatory support to maintain appropriate end-organ function in patients with end-stage heart failure. The advantages of the newer continuous-flow devices can be safely applied to an increasing number of patients. Long-term studies (>1 year) are needed to assess effects on end-organ function with continuous-flow devices, which may have important implications for use as destination therapy.