A recent study published in the Annals of Internal Medicine reports that in patients with atherosclerotic renal artery stenosis (ARAS), stenting of the renal artery has no clear effect on the progression of renal dysfunction over a 2-year period compared with optimal medical management. In addition, stenting was associated with serious complications such as procedure-related deaths and the need for dialysis.

Current guidelines suggest that stenting is a reasonable strategy in patients with only one kidney or with bilateral kidney disease and can be considered in cases of unilateral kidney disease. However, there is little outcomes-based evidence to support this recommendation. A team of European-based researchers enrolled 140 patients with ARAS of at least 50% and impaired renal function, defined by creatine clearance < 80/mL/1.73 m². Of 140 patients, 64 were assigned to undergo stent placement and medical treatment—comprising treatment of hypertension, a statin, and aspirin—and 76 to receive medical treatment only. All of the patients randomized to medical care received treatment; however, only 46 of 64 patients assigned to receive a stent actually underwent the procedure: 12 were found to have stenosis less than 50%, 2 refused the stent, 1 underwent angioplasty, 2 were unable to undergo stenting due to technical difficulties, and 1 patient died.

The primary endpoint was a worsening of renal function, measured by a 20% decrease or more in creatine clearance, and secondary outcomes included cardiovascular morbidity, mortality, and safety. At 24 months, renal function worsened in 16% of the patients in the stent group and in 22% of those in the medication group. However, there was no clinical significance noted between the two groups (hazard ratio [HR], 0.73; 95% confidence interval [CI], 0.33 to 1.61). In the stent group, serious complications included 2 procedure-related deaths (3%), 1 late death from an infected hematoma, and 1 patient who required dialysis due to a cholesterol embolism. Other secondary outcomes were not different between groups.

The key limitation of this study was the inability of imaging techniques to identify many patients with less than 50% ARAS, which resulted in the study’s being underpowered to provide adequate estimates of efficacy. Since the procedure did not significantly improve the primary outcome but led to serious complications, the authors suggest that for now, the best approach to treating patients with ARAS is a conservative approach that avoids stenting and focuses on the management of cardiovascular risk factors.

1. Bax L, Wolttlez AJ, Kouwenberg HJ, et al. Stent placement in patients with atherosclerotic renal artery stenosis and impaired renal function: a randomized trial. Ann Intern Med. 2009;150(12):840-848. Abstract available at: http://www.annals.org/cgi/content/abstract/150/12/840. Accessed July 8, 2009.

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This entry was posted on Wednesday, July 8th, 2009 at 12:00 pm.