(1052) - Combined Renal Risk Score Predicts Post-Implant Renal Failure in Continuous-Flow Left Ventricular Assist Device (CF-LVAD) Patients

Abstract

Acute kidney injury failure requiring renal replacement therapy (RRT) effects morbidity and mortality of patients on CF-LVAD support. Currently available MCS guidelines do not offer a decision-making algorithm for CF-LVAD candidates with poor baseline renal function. We reviewed records of 389 CF-LVAD patients implanted between January 2004 and August 2015 at a large academic institution. We compared preoperative renal function between those who did or did not require postoperative RRT, using serum creatinine (SCr), dipstick proteinuria, urine protein-creatinine ratio (UPCR) and estimated glomerular filtration rate (eGFR) by the MDRD equation. Patients were categorized based on requirement for RRT following CF-LVAD implantation. ROC curve analysis was performed to define appropriate cut-offs for significant risk factors. Overall, 44 CF-LVAD patients (11.6%) required post-implant RRT. Patients requiring RRT had significantly worse preoperative renal function than those who did not, as indicated by mean SCr (2.2 vs. 1.4 mg/dL, p<0.05) and mean UPCR (1.33 vs. 0.32, p<0.05). Low eGFR-MDRD (less than 40 mL/min/1.73 m2, OR 10.6, p<0.001) and elevated UPCR (greater than 0.55, OR 8.76, p<0.001) were independent predictors of RRT, as was dipstick proteinuria (greater than 2+ proteinuria, OR 8.09, p<0.001). We created a combined VAD renal risk score (CVRRS), where 2 = low eGFR + elevated UPCR; 1 = low eGFR or elevated UPCR; and 0 = normal eGFR and UPCR. The risk of postoperative RRT was significantly greater with a CVRRS of 2 (63.6%), compared with a CVRRS of 1 (19.6%) and CVRRS of 0 (2.2%), (p<0.001, Fig. 1A). CVRRS provided better discrimination for prediction of need for RRT than eGFR or UPCR alone (Fig. 1B). A CVRRS of 2 (low eGFR + elevated UPCR) is a significant predictor of RRT requirement after CF-LVAD implantation. We recommend its routine preoperative assessment in CF-LVAD candidates to guide expectations and decision-making.