Kidney Function Trajectories With Mechanical Circulatory Support.

Area of Science:

• Cardiology
• Nephrology
• Biomedical Engineering

Background:

• Adverse kidney outcomes are common in left ventricular assist device (LVAD) recipients but poorly understood.
• Creatinine-based estimated glomerular filtration rate (eGFR) is used to assess kidney function but has uncertain validity and nonlinear changes post-LVAD.

Purpose of the Study:

• To investigate nonlinear eGFR trajectories within 90 days post-LVAD implantation.
• To explore relationships between eGFR trajectory parameters, patient factors, and clinical outcomes.

Main Methods:

• Utilized two cohorts: a single-center (n=190) and a US national (n=10794) LVAD recipient cohort.
• Employed segmented linear regression with two segments to model eGFR trajectories, comparing it with other models.
• Assessed associations of trajectory parameters with patient factors and clinical outcomes.

Main Results:

• Segmented linear regression provided the best fit, identifying early/late slopes, breakpoint time, and breakpoint eGFR.
• Patient factors like female sex and older age were associated with late trajectory slopes.
• All four trajectory parameters correlated with survival; breakpoint eGFR and late slope remained significant after adjustment.

Conclusions:

• Kidney function post-LVAD implantation follows a biphasic trajectory (early/late linear phases with a breakpoint).
• These trajectory metrics correlate with survival and preimplantation factors.
• The identified metrics can inform research into adverse kidney outcomes and interventions for LVAD patients.