Persistent Renal Dysfunction Preceding Left-Ventricular Assist Device Implantation Predicts Increased Mortality and Diminished Left-Ventricular Unloading

Abstract

Background: A significant proportion of left-ventricular assist device (LVAD) recipients have pre-implantation renal dysfunction. However, the renal and clinical outcomes for these patients have not been explored in an Australian cohort. Methods: Data were retrospectively collected for 120 consecutive LVAD recipients at a single health service. Patients with persistent renal dysfunction pre-VAD were defined as having an average eGFR <60 ml/min/1.73 m2 in the eight weeks preceding LVAD insertion (Group 1, n = 38), and were compared to patients with average eGFR >60 ml/min/1.73 m2 in the same time frame (Group 2, n = 82). Results: Improvement in eGFR between pre-VAD and 6-months post-VAD was similar in Groups 1 and 2 (16 ± 22 vs 23 ± 26 ml/min/1.73 m2, p = 0.18). At six months post-LVAD, Group 1 patients demonstrated significantly higher left-atrial volume index (54 ± 31 ml/m2 vs 41 ± 19 ml/m2, p = 0.01) and pulmonary capillary wedge pressure (PCWP) (16 ± 7 mmHg vs 11 ± 5 mmHg, p = 0.01). In a multivariate regression analysis controlling for pre-VAD PCWP, LV end-diastolic diameter, LV ejection fraction and body surface area, eGFR pre-VAD was found to be an independent predictor of PCWP 6 months post-VAD (R2 = 0.43, p = 0.001). All-cause mortality was higher for Group 1 patients at 1 month (6% vs 18%, p = 0.03) and 6 months (7% vs 24%, p = 0.02) post-VAD. Mean time to transplant waitlisting was higher in Group 1 (4.8 ± 1.8 months vs 3.7 ± 1.5 months, p = 0.01). Conclusion: Patients with concomitant heart failure and persistent renal dysfunction may demonstrate partial renal recovery following LVAD implantation. However, these patients are less likely to achieve optimal reduction in pulmonary pressures and have higher rates of LVAD mortality.