Worsening Renal Function in Cardiac Mechanical Support

Background: Venous congestion in heart failure (HF) may lead to worsening renal failure (WRF). We hypothesised that WRF in patients hospitalised for left ventricular assist device (LVAD) implantation is associated with increased 1-year mortality. There is limited data regarding WRF in HF patients with mechanical support. The objective of this paper is to determine whether WRF in HF patients hospitalised for LVAD implantation is associated with increased 1-year mortality and to identify risk factors for WRF.

Methods: We performed a single centre retrospective chart analysis of 162 patients who received an LVAD between August 2006 and December 2014 with pre-LVAD right heart catheterisation data. We stratified patients to those who demonstrated WRF and the use of haemodialysis (HD) or ultrafiltration (UF).

Results: Patients with a higher central venous pressure (CVP) >16 mmHg (17-24 mmHg range) developed WRF (29.7% vs. 14.1%, p=0.019). A CVP ≥16 and glomerular filtration rate (GFR) <30 ml/min/1.74m² increased the odds of WRF. Worsening renal failure and HD/UF use were associated with increased 1-year mortality. Furthermore GFR <30, atherosclerosis, and right ventricular failure were independent predictors for increased 1-year mortality. A GFR <30 increased the odds of developing WRF five-fold (OR 4.14, CI [1.95-8.78], p<0.0001), and GFR <30 and central venous pressure (CVP) >16 increased the odds of requiring HD/UF.

Conclusions: Worsening renal failure is associated with a higher CVP at the time of LVAD implantation and increases the risk of 1-year mortality and the odds of requiring HD/UF. Careful evaluation of renal function and comorbid conditions during LVAD implantation is critical to reduce mortality and for risk stratification.