Adding renal-artery stenting to comprehensive medical therapy did not confer significant benefit with respect to the prevention of clinical events in patients with atherosclerotic renal-artery stenosis and hypertension or chronic kidney disease in the randomized controlled CORAL trial.
During a median follow-up of 43 months in the multicenter, open-label trial, the rate of a primary composite endpoint consisting of death from cardiovascular or renal causes, myocardial infarction, stroke, hospitalization for heart failure, progressive renal insufficiency, or the need for renal replacement therapy did not differ significantly between 459 patients randomized to receive medical therapy plus renal-artery stenting, and 472 patients randomized to receive medical therapy alone (35.1% and 35.8%, respectively; hazard ratio with stenting, 0.94), Dr. Christopher J. Cooper reported at the American Heart Association scientific sessions.
Dr. Christopher Cooper
Furthermore, no significant differences were seen between the treatment groups in the rates of the individual components of the composite primary endpoint, or in all-cause mortality. There was, however, a consistent, modest improvement in systolic blood pressure in the stent group (–2.33 mm Hg vs. the medication only group), noted Dr. Cooper of the University of Toledo (Ohio) and his coinvestigators.
The findings of the Cardiovascular Outcomes in Renal Atherosclerotic Lesions (CORAL) trial were published online simultaneously with the Nov. 18 presentation (N. Engl. J. Med. 2013 Nov. 18 [doi:10.1056/NE/NEJMoa1310753]).
CORAL comprised adults with a mean age of 69 years who had atherosclerotic renal-artery stenosis and either chronic kidney disease or systolic hypertension (despite taking at least two antihypertensive drugs). They were recruited during May 2005–January 2010.
Mandated medications as per the study protocol (unless contraindicated) included the angiotensin II type-1 receptor blocker candesartan with or without hydrochlorothiazide, and the combination agent amlodipine-atorvastatin dose-adjusted on the basis of blood pressure and lipid status.
The findings are important because renal artery stenosis is present in 1%-5% of people with hypertension, and in up to 7% of those over age 65 years, the investigators noted.
Although uncontrolled studies in the 1990s suggested that renal-artery angioplasty or stenting results in significant reductions in systolic blood pressure and stabilization of chronic kidney disease (findings which led to a 364% increase in the number of procedures among Medicare beneficiaries between 1996 and 2000), subsequent randomized trials failed to show a benefit of renal-artery angioplasty on blood pressure or of renal-artery stenting on kidney function, they noted.
The current study is among the first to specifically assess clinical outcomes, and based on the findings, "it is clear that medical therapy without stenting is the preferred management strategy for the majority of people with atherosclerotic renal-artery stenosis," they said.
"A key issue in the interpretation of our results is whether the medical therapy that was given to CORAL participants can be replicated in clinical practice. The medical therapy in our study included the use of an angiotensin-receptor blocker, with or without a thiazide-type diuretic, with the addition of amlodipine for blood-pressure control. In addition, participants received antiplatelet therapy and atorvastatin for management of lipid levels, and diabetes was managed according to clinical practice guidelines," they wrote, noting that with this regimen, "patients who received medical treatment alone had remarkably good cardiovascular and renal outcomes, despite their advanced age and the high rates of hypertension, diabetes, chronic kidney disease, and other coexisting cardiovascular conditions."
The National Heart, Lung, and Blood Institute and the National Institutes of Health funded the trial, with support from Cordis – which donated a short-tip Angioguard device – and Pfizer. AstraZeneca and Pfizer donated medications. Dr. Cooper reported having no conflicts of interest. Detailed disclosures for all investigators are available with the full text of the article at nejm.org.