Background: Treatment options for atherosclerotic renal artery stenosis (ARAS) include medical therapy alone or renal artery revascularization with continued medical therapy, most commonly by percutaneous transluminal renal angioplasty with stent placement (PTRAS). This review updates a prior Comparative Effectiveness Review of management strategies for ARAS from 2006, which was updated in 2007.
Objectives: Compare the effectiveness and safety of PTRAS versus medical therapy, and also versus surgical revascularization, to treat ARAS. Identify predictors of outcomes by intervention.
Data sources: MEDLINE®, Embase®, the Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews from inception to March 16, 2016; eligible studies from the original reports and other relevant existing systematic reviews; and other sources.
Review methods: We included studies comparing ARAS interventions, single-group prospective PTRAS and medical therapy studies, and prospective or retrospective surgery studies. We also included 20 recent case reports of patients with acute ARAS decompensation. Outcomes included all-cause and cardiovascular mortality, cardiovascular events, renal replacement therapy (RRT), other kidney events and function, hypertension events, blood pressure (BP), medication use, and adverse events.
Results: From 1,454 citations, we included 78 studies and 20 case reports. We included 9 randomized controlled trials (RCTs), 11 nonrandomized comparative studies, 67 cohorts (in 63 studies) of PTRAS; 20 cohorts (in 17 studies) of medical therapy alone; and 4 cohorts of surgery. For the primary comparison of PTRAS versus medical therapy, seven RCTs found no difference in mortality, RRT, cardiovascular events, or pulmonary edema. They mostly found no difference in kidney function or BP control after PTRAS. Procedural adverse events were rare but medication-related adverse events were not reported. The nonrandomized studies were more variable than the RCTs and found no significant difference in mortality, but heterogeneous effects on kidney function and BP control after PTRAS. All 20 case reports describe patients with successful clinical and symptomologic improvement after revascularization. In subgroup analyses, two RCTs found no patient characteristics associated with outcomes between PTRAS and medical therapy. In one retrospective comparative study, patients with flash pulmonary edema or both rapidly declining kidney function and refractory hypertension had decreased mortality with PTRAS (vs. medical therapy). Single-intervention studies found that various factors predicted outcomes.
Conclusions: There is a low strength of evidence of no statistically significant or minimal clinically important differences in important clinical outcomes (death, cardiovascular events, RRT) or BP control between PTRAS and medical therapy alone, and that kidney function may improve with PTRAS. Clinically important adverse events related to PTRAS are rare; however, studies generally did not report medication-related adverse events. Based on the evidence, subsets of patients benefit from revascularization, but the evidence does not clearly define who these patients are, except that case reports demonstrate that some patients with acute decompensation benefit from revascularization. Evidence is limited regarding differences in outcomes based on different PTRAS-related treatments. The RCTs had limited applicability to many patients for whom PTRAS is recommended, particularly those who present with pulmonary edema or rapidly declining kidney function. All nonrandomized trials were inadequately adjusted to account for underlying differences between patients undergoing different interventions. New studies or reanalyses of data in existing studies are needed to better understand the comparative effectiveness of PTRAS versus medical therapy.