No high-quality evidence exists to suggest a benefit to stenting for renal artery stenosis on hard clinical endpoints, a systemic review of the literature determined.
Percutaneous renal angioplasty with stent placement was comparable with medical therapy alone for mortality, progression to end-stage renal disease, and cardiovascular events, according to Ethan M. Balk, MD, MPH, of Brown University School of Public Health in Providence, R.I., and colleagues.
But, the team noted that no study included in their analysis, published online in Annals of Internal Medicine, was really powered to detect a difference between the treatments.
Patients receiving angioplasty had an advantage in subsequent kidney function, although the studies did not adjust for confounders. Blood pressure control rates also seemed to favor this group, although with conflicting results among the studies, they added.
“The strength of evidence regarding the relative benefits and harms of [renal angioplasty] versus medical therapy alone for patients with atherosclerotic renal artery stenosis is low. Studies have generally focused on patients with less severe [stenosis],” they wrote.
Balk’s group conducted their systemic review using data from 83 randomized and nonrandomized studies.
They urged: “Future studies should focus on patients who are putatively most likely to benefit from [renal stenting], namely those with proven hemodynamically significant atherosclerotic renal artery stenosis or those who have signs of decompensation. In contrast to most existing [non-randomized studies], future observational studies should adequately control for underlying differences between patients who undergo [renal stenting] and those who continue medical therapy, ideally with propensity score-adjusted analysis.”
For now, observational studies suggest that patients with worse kidney function, higher blood pressure, or flash pulmonary edema may be more likely to have improved kidney function and blood pressure with [renal stenting], Balk and colleagues commented.
Yet “whether these patients have benefits in survival and avoidance of cardiovascular events and renal replacement therapy compared with those who continue medical therapy remains unclear.”
Balk reported receiving grants from the Agency for Healthcare Research and Quality.
Annals of Internal Medicine
Raman G, et al “Comparative effectiveness of management strategies for renal artery stenosis: an updated systemic review” Ann Intern Med 2016; DOI: 10.7326/M16-1053.