Renal Outcomes Following Left Ventricular Assist Device Placement: A Single Center Experience

Introduction Renal dysfunction is a prognostic factor in morbidity and mortality after left ventricular assist device (LVAD) placement. As a result, poor renal function often affects a patient's eligibility for LVAD implantation. However, in some, cardiac output augmentation following LVAD placement may improve renal perfusion. The extent of change in renal function and predictors of long-term renal function post-LVAD implantation have not been well studied. Methods This retrospective cohort included consecutive patients who underwent LVAD implantation (HeartMate[HM] II and HM3) between 2008-2018 at a single center for both bridge-to-transplant and destination therapy (DT) indications. We examined the relationship of clinical parameters with changes in renal function 6 months post-LVAD. Glomerular filtration rate (GFR) was calculated using Modification of Diet in Renal Disease Study equation. We performed multivariable logistic regression analyses to determine predictors of decreased renal function. Results We examined 91 patients (mean age 59.7± 13.2, female 11%, HM II 89%, DT 68%). Post-LVAD, 52 patients (57.1%) improved and 39 (42.9%) had deterioration in renal function (Table). Among all patients, 16 (17.6%) had more than 25% reduction in GFR, 6 (6.6%) had a post-LVAD GFR of less than 30 mL/min/1.73 m2, and 2 (2.2%) developed end stage renal disease (ESRD) requiring dialysis. Of those patients who had improved GFR post-LVAD, 30 (57.7%) had more than 25% improvement in their GFR. Among patients who had a GFR <30 mL/min/1.73 m2 pre-LVAD placement (n=7), only 3 had a GFR of < 30 mL/min/1.73 m2 post-LVAD. In those who had a decrease in GFR, the median decrease was 11.5 (interquartile range[IQR] 4.1 - 23.1) and in those who had an increase in GFR the median increase was 16.3 (IQR 8.4 - 28.6). Elevated RA pressure was associated with decreased renal function (Odds ratio [OR] 2.47, 95% Confidence interval [CI] 1.04- 5.89, p=0.04) and >25% reduction in GFR (OR: 3.96, 95% CI 1.4 - 13.8), p=0.03). None of the other clinical parameters listed in the Table were associated with worse renal outcomes. Pre-LVAD GFR was also not predictive of >25% post-implant GFR reduction or the development of ESRD. Conclusion Renal function may improve after LVAD placement. In patients with long-term decreased renal function post-LVAD, the reduction in GFR was rarely severe. Elevated RA pressure, a marker of right ventricular dysfunction and volume overload, is potential predictor of poor renal outcomes after LVAD placement.