No Benefit from Renal Stents
Renal stents are not better tha noptimal medical therapy alone for renal artery stenosis.
PHILADELPHIA—Placing renal artery stents in patients with atherosclerotic renovascular disease is not associated with improved outcomes when compared with optimal medical therapy alone, researchers reported here at the American Society of Nephrology's Renal Week conference.
The findings come from the Angioplasty and Stenting for Renal Artery Lesions (ASTRAL) study, the largest randomized trial of patients with atherosclerotic renovascular disease. Conducted at 58 centers in the United Kingdom, Australia, and New Zealand, the trial recruited 806 patients between 2000 and 2007.
Patients (mean age 71 years, 63% male) were randomized to receive medical treatment alone or to undergo revascularization in addition to medical treatment. The mean percent of stenosis was 76%. Subjects had a mean glomerular filtration rate of 40 mL/min/1.73 m2 and mean BP of 150/76 mm Hg. Measured outcomes included kidney function, BP, major kidney events, major cardiovascular events, and death.
The two groups showed no significant differences in any of the outcome measures. For example, after a mean follow-up of 33 months (range 12 months to seven years), 100 patients in the medical-treatment-only group and 83 in the revascularization group experienced 132 and 109 cardiovascular events, respectively.
Forty-one patients who received medical treatment alone and 43 revascularized patients experienced 53 and 51 renal events, respectively. The four-year mortality rate was 32% in both groups.
Lead nephrologist for the trial, Philip Kalra, MD, told Renal & Urology News that these findings should make physicians carefully consider whether renal revascularization might benefit their patients before undertaking such procedures. “If you have asymptomatic patients who have anatomical severe disease with renal artery stenosis, then there is no benefit with revascularizing them over medical therapy. Medical therapy is just as good,” said Dr. Kalra, a consultant nephrologist and lead researcher at Salford Royal Hospitals and University of Manchester, in the U.K.
“You need to also consider the expense of the angioplasty and stent procedure, and of course, there is a definite small risk to the patients associated with revascularization. At least 10% are likely to have some complication, and about 2% or 3% will have a serious complication, like blocking off [of] a kidney artery or tearing of a vessel. So revascularization should not be performed with impunity.” He did wish to point out that “there are likely to be sub-groups of patients who do benefit from revascularization, and the current need is to find ways of identifying this minority of patients.”