Early Gains in Renal Function Following Implantation of HeartMate II Left Ventricular Assist Devices May not Persist to One Year

Renal function improves early after left ventricular assist device (LVAD) implantation but later decline has been observed. We sought to determine the occurrence and evaluate possible causes for this decline. In 62 consecutive patients with HeartMateII LVAD with available calculated glomerular filtration rate (GFR, ml/min/1.73m) one year after implant, GFR was assessed repeatedly and possible predictors for decline from 3 to 12 months were investigated. Post-mortem renal specimens for patients supported with an LVAD were evaluated. GFR at admission (54.5±19.5), increased to 66.4±22.3 pre-operatively and to 79.2±30.1 ~one month after implantation. Subsequently at ~3 months GFR declined to 74.7±25.4, at ~6 months to 68.8±23.1 and ~1 year after implant to 63.9±17.7. GFR at 1 year was significantly lower (p<0.0001, p<0.0001, p=0.005) than GFR 1, 3 and 6 months after implant. Early rise in GFR after surgery was not associated with late decline. Shorter bypass time (β=-0.09, p=0.048) and higher albumin 3 months after LVAD (β=14.4, p=0.025) were significantly associated with less later decline in GFR. Arteriosclerosis was identified in autopsy renal specimens.In conclusion, early gains in renal function after LVAD implant are not sustained in many patients. Patient, device and operative factors may influence long-term renal function in these patients.