End-organ function in patients on long-term circulatory support with continuous- or pulsatile-flow assist devices

Limited data exist about the long-term effects of continuous-flow vs pulsatile-flow left ventricular assist devices (LVADs) on end-organ function.

We reviewed the data of patients who underwent LVAD implantation at our institution between 1989 and 2004 and who were supported for >6 months. The continuous-flow (C-LVAD) group included 12 patients bridged to transplant with either a Jarvik 2000 or a Thoratec HeartMate II LVAD. The pulsatile (P-LVAD) group included 58 patients supported by a Thoratec HeartMate I LVAD. Follow-up was up to 15 months after LVAD implantation. Average duration of LVAD support was 370 +/- 182 days (range 180 to 754) for the C-LVAD group and 315 +/- 111 days (range 180 to 1,334) for the P-LVAD group.

Patients from both groups were comparable for age, gender, body weight, cardiac index, ejection fraction, creatinine, blood urea nitrogen, creatinine clearance, albumin, total bilirubin, and transaminase levels before implantation. C-LVAD patients had a lower pre-operative hemoglobin than did P-LVAD patients (10.5 +/- 1.7 g/dl vs 12.2 +/- 1.9 g/dl; p = 0.01). In both groups, albumin, blood urea nitrogen, creatinine, creatinine clearance, total bilirubin, and transminase levels either improved or stayed within the normal range at 6, 9, 12, and 15 months after LVAD implantation. Four of the 12 C-LVAD patients and 28 of the 58 P-LVAD patients underwent cardiac transplantation. Actuarial survival, censored for transplant, at 9, 12, and 15 months was 90% for the C-LVAD group and 88%, 78%, and 74% for the P-LVAD group (p = not statistically significant).

On the basis of these data, it appears that continuous- and pulsatile-type LVADs provide adequate blood flow to maintain proper end-organ function during prolonged circulatory support.