Predictors and Outcomes of Renal Replacement Therapy After Left Ventricular Assist Device Implantation

Objective: To examine the frequency and outcomes of patients requiring renal replacement therapy (RRT)early after left ventricular assist device (LVAD)implantation. Patients and Methods: We examined use of in-hospital RRT and outcomes in consecutive adults who underwent continuous-flow LVAD implantation from February 15, 2007, through August 8, 2017. Logistic regression was used to examine predictors of RRT. The associations of RRT with outcomes were examined using Cox proportional hazards regression. Results: Of 354 patients who underwent LVAD implantation, 54 (15%)required in-hospital RRT. Patients receiving RRT had higher preoperative Charlson Comorbidity Index values (median, 5 vs 4; P=.03), Model for End-Stage Liver Disease scores (mean, 19.0 vs 14.5; P<.001), right atrial pressure (mean, 19.1 vs 13.4 mm Hg; P<.001), and estimated 24-hour urine protein levels (median, 357 vs 174 mg; P<.001)and lower preoperative estimated glomerular filtration rate (eGFR)(median, 43 vs 57 mL/min; P<.001)and measured GFR using ¹²⁵I-iothalamate clearance (median, 33 vs 51 mL/min; P=.001)than those who did not require RRT. Approximately 40% of patients with eGFR less than 45 mL/min/1.73 m² and 24-hour urine protein level greater than 400 mg required RRT vs 6% with eGFR greater than45 mL/min/1.73 m² and without significant proteinuria. Lower preoperative eGFR, higher estimated 24-hour urine protein level, higher right atrial pressure, and longer cardiopulmonary bypass time were independent predictors of RRT after LVAD implantation. Of patients requiring in-hospital RRT, 18 (33%)had renal recovery, 18 (33%)required outpatient hemodialysis, and 18 (33%)died before hospital discharge. After median (Q1, Q3)follow-up of 24.3 (8.9, 49.6)months, RRT was associated with increased risk of death (adjusted hazard ratio [HR], 2.86; 95% CI, 1.90-4.33; P<.001)and gastrointestinal bleeding (adjusted HR, 4.47; 95% CI, 2.57-7.75; P<.001). Conclusion: In-hospital RRT is associated with poor prognosis after LVAD. A detailed preoperative assessment of renal function before LVAD may be helpful in risk stratification and patient selection.