Abstract 19757: Severity of Renal Artery Stenosis Predicts Baseline and Residual Renal Function In Patients Undergoing Renal Artery Stenting
The factors that lead to ischemic nephropathy, or loss of kidney function in patients with renal artery stenosis (RAS), are poorly described. Several prior studies suggested that the degree of renal artery stenosis (RAS) is not associated with GFR.
Method: One hundred patients at 7 centers undergoing renal artery stenting were randomly assigned to an embolic protection device or double-blind use of a platelet glycoprotein IIb/IIIa inhibitor in a 2x2 factorial design. GFR was measured by a blinded lab using Cr-derived MDRD, cystatin C, and iohexol clearance. Angiograms were independently analyzed with lesion length (LL), minimal luminal diameter (MLD), reference diameter and percent stenosis (%S) measured.
Results: Baseline MDRD GFR was associated with high baseline LDH (-.24, p<0.05), presence of CHF (p<0.05), bilateral renal artery stenosis (p<0.05), LL (.41, p=0.0001), % stenosis (-.27, p=0.01), and MLD (.32, p<0.0001). By multivariate analysis LDH (-.08, p<0.05), bilateral stenosis (p=0.06), CHF (p=0.008), and LL*MLD (p<0.0001) remained significant. Baseline cystatin C calculated GFR was associated with the same univariate factors. GFR 1-month after stenting was associated with ACE inhibitor use (p<0.05), procedural contrast volume (.27, p=0.01), bilateral stenosis (p<0.05), LL (p<0.05) and MLD (.23, p<0.05). A new variable was created as baseline % stenosis / MDRD GFR and was highly predictive of change in GFR 1-month after stenting (0.30, p<0.005) as was treatment assignment (p=0.01) (Figure 1).
Conclusions: Lesion characteristics (bilateral stenosis, MLD and lesion length) are determinants of GFR before and after renal artery stenting. Importantly, the change in renal function after stenting appears to be strongly influenced by baseline % stenosis and MDRD GFR, in addition to treatment with Abciximab and embolic protection. Figure 1. Predictive probability of improved 1 Month GFR using the ratio of % stenosis and baseline GFR
- © 2010 by American Heart Association, Inc.