Complete versus partial distal embolic protection during renal artery stenting

Objective: The aim of this study was to evaluate whether complete embolic protection is superior to partial embolic protection for preservation of kidney function during renal artery angioplasty and stenting. Background: Renal artery angioplasty and stenting (RAAS) is a common treatment for atherosclerotic renal artery stenosis. However, RAAS may be complicated by peri-procedural loss of kidney function. Methods: In total, 44 patients were randomized to embolic protection devices (EPD) use; 25 complete and 19 partial embolic protection. These patients were further randomized to receive abciximab (n = 23) or placebo (n = 20). MDRD glomerular filtration rate (GFR), was used as the primary measure of renal function. Creatinine was measured by a modified Jaffe reaction using the IDMS-traceable assay. The primary endpoint was the percent change in estimated glomerular filtration rate (eGFR) 1 month following stent placement. Results: There was no difference in percent change eGFR at 1 month between complete or partial protection (-4 ± 25 vs. +3 ± 30, P = 0.45). Abciximab was associated with a net improvement in eGFR when compared with placebo (+0.5 ± 27 vs. -11 ± 20, P = 0.04). On subgroup analysis, the use of abciximab was associated with significantly improved eGFR in the partial distal embolic protection group (+14 ± 33 vs. -17 ± 13 %, P = 0.018) but not in the complete distal embolic protection group (+2.5 ± 26 vs. -11 ± 24, P = 0.42), however, there was no interaction between completeness of protection and abciximab on eGFR (P = ns). Capture of embolic material was more likely with complete protection when compared with those receiving partial protection (51% vs. 21%, P < 0.05). Conclusion: Complete protection was superior to partial protection for the capture of athermanous debris during renal artery stenting. However, this was not associated with improved renal function. Importantly, Abciximab conferred a benefit for renal function that was independent of the degree of embolic protection.