Damage Control for Renal Artery Stenting

Abstract

Chronic kidney disease is associated with an increased risk of death in ambulatory patients,1 patients with heart disease,2 and in those undergoing cardiac procedures.3 Slowing the progression of kidney damage should improve survival. Article p 2752 Stenting of atherosclerotic renal artery stenoses is commonly performed in an attempt to preserve renal function and control blood pressure. The number of Medicare recipients undergoing renal artery angioplasty or stent placement has increased strikingly from 7660 cases in 1996 to 18 520 cases in 2000,4 but evidence of benefit remains “sparse and inconclusive.”5 In this issue of Circulation , Cooper and colleagues report the results of a randomized trial of patients undergoing renal artery stenting to determine whether a filter-based embolic protection device (EPD), the platelet glycoprotein inhibitor abciximab, or both in combination improves renal function.6 The results were more negative than anticipated. Glomerular filtration rates (GFR) worsened 30 days after renal stenting in 3 treatment groups and remained unchanged in the fourth group treated with combination therapy (see Table). Secondary comparisons among the treatment groups suggested that the combination of an EPD with abciximab caused the smallest changes in GFR, but no treatment could improve renal function over that existing at baseline before renal artery stenting was carried out. View this table: Table. Summary Results of the Primary (1°) End Point of Absolute Change in Glomerular Filtration Rate (ΔGFR) and Percentage Change From Baseline to 30 Days After Renal Artery Stenting Plus Abciximab, Filter-Based Embolic Protection, or Both The investigators estimated GFR from the creatinine-based Modification of Diet in Renal Disease formula and corroborated the results with measurements of cystatin C. Cystatin C, a cysteine protease inhibitor produced by nearly all human cells, is a nonglycosylated basic protein with a low molecular mass (13 kDa) that is freely filtered …