Background: The ASTRAL trial (Angioplasty and Stenting for Renal Artery Lesions) recruited 806 patients between 2000 and 2007. Patients with atherosclerotic renal artery stenosis (RAS) and clinician uncertainty about the benefit of revascularization were randomized 1:1 to medical therapy with or without renal artery stenting. The initial results were presented in 2009 at a median 33.6-month follow-up, with no benefit of revascularization on renal or cardiovascular outcomes. Surviving patients remained under follow-up until the end of 2013, and the long-term results are presented in this study.
Methods: Data were analyzed to assess whether there was a later impact of revascularization on renal function, cardiovascular events, and survival, including a composite outcome of renal and cardiovascular outcomes and death (as in the CORAL trial [Cardiovascular Outcomes in Renal Atherosclerotic Lesions]). Prespecified subgroup analyses included different categories of renal function, rapid deterioration in kidney function, and degree of RAS. Post hoc analyses of patients with severe RAS (bilateral 70% or >70% in a solitary kidney), those with or without proteinuria, and a per-protocol analysis were performed.
Results: The mean age of the entry population was 70.5 years, the mean estimated glomerular filtration rate was 40 mL/min/1.73 m2, the mean RAS was 76%, and the mean blood pressure was 150/76 mm Hg; 83% of the revascularization group underwent attempted stenting. The median follow-up was 56.4 months, with 108 patients lost to follow-up. By the end of follow-up, 50% of the evaluable population had died, 18% had suffered a first renal event, and 40% had suffered a first cardiovascular event. No statistical difference was observed for any outcome in the intention-to-treat and per-protocol analyses.
Conclusions: The long-term follow-up of the ASTRAL trial showed no overall benefit of renal revascularization to renal and cardiovascular outcomes. It has been highlighted that a proportion of the population had lower-risk RAS, and there is likely to be merit in further study in a higher-risk population.
Registration: URL: https://www.isrctn.com; Unique identifier: ISRCTN59586944.
Keywords: atherosclerosis; blood pressure; follow-up studies; kidney; renal artery.