Shelley Wood

November 18, 2013

DALLAS, TX — Renal-artery stenting in people with renal-artery stenosis offers no advantages over best medical therapy in reducing hard clinical events, the Cardiovascular Outcomes in Renal Atherosclerotic Lesions (CORAL) study has found[1].

The study results are in line with other randomized trials that have looked at blood-pressure effects or kidney function and should markedly curtail the number of procedures being performed.

"This trial absolutely showed, without question, that in patients who have hypertension and renal-artery disease, medical therapy was just as effective as interventional therapy," CORAL study coauthor Dr Michael Jaff (Massachusetts General Vascular Center, Boston) told heartwire . "But what it doesn't talk about are patients who weren't in the trial or patients who failed medical therapy. . . . The bottom line is, this will and should change medical practice by making sure these eligible patients are given a really good try at intensive medical therapy long before you consider using a renal-artery stent."

Dr Christopher J Cooper

Lead author Dr Christopher J Cooper (Rhode Island Hospital, Providence) presented the results here today at the American Heart Association 2013 Scientific Sessions ; the findings have been published simultaneously in the New England Journal of Medicine.

The CORAL Study

Renal-artery stenosis first became popular during the 1990s on the heels of several nonrandomized studies, with the number of procedures increasing by 364% between 1996 and 2000, Cooper et al note in their paper.

In recent years, enthusiasm for renal-artery stenting has dimmed somewhat, according to Jaff. That was largely on the basis "of what I consider to be two pretty flawed trials," ASTRAL and STAR , that nonetheless led to a drop-off in the number of patients being referred for renal-artery stenting.

The CORAL trial, funded by the National Heart, Lung, and Blood Institute (NHLBI), was launched in 2005, ultimately enrolling 947 patients with renal-artery atherosclerosis (stenosis >60%) who had either systolic hypertension and were taking two or more blood pressure-lowering drugs or chronic kidney disease. They were randomized equally to medical therapy alone or medical therapy plus renal-artery stenting. Crossovers—which were criticized in other trials of renal-artery stenting—were strictly controlled in CORAL, which strengthens the overall findings, Jaff stressed.

At a median follow-up of 43 months, the rate of the primary composite end point (death from CV or renal causes, MI, stroke, hospitalization for congestive heart failure, progressive renal insufficiency, or need for kidney replacement) was no different between groups. In both groups, the primary end point occurred in 35% of patients.

There were also no differences in rates of individual components of the end point or in rates of all-cause mortality.

A "very modest difference" in systolic blood pressure was seen between groups (–2.3 mm Hg in the stenting group), but this clearly did not translate into clinically meaningful differences. Of note, 11 patients suffered an arterial dissection in the stenting group.

Still Unknown

From these results, Cooper et al concluded, "it is clear that medical therapy without stenting is the preferred management strategy for the majority of people with atherosclerotic renal-artery stenosis."

That sentiment is echoed in an editorial accompanying the paper[2].

According to Dr John A Bittl (Munroe Regional Medical Center, Ocala, FL), the CORAL trial is "a definitive test" of this therapy. "The trial results send a clear message to patients and referring physicians. Until new treatments are found to be safe and effective, patients in everyday practice who have moderately severe atherosclerotic renovascular disease and either hypertension or stage 3 chronic kidney disease should receive medical therapy to control blood pressure and prevent the progression of atherosclerosis but should not be corralled into getting a renal-artery stent."

Jaff, however, maintained that there will still be a role for renal-artery stenting, specifically in patients in whom intensive medical treatment has been tried and failed to yield any clinical benefits.

Making sure medication is monitored and titrated appropriately is key, Jaff noted, adding that compliance in this study was very good. "We as physicians need to be much more aggressive about giving medications," he said.

He acknowledged that medication adherence is higher in patients in randomized trials than the real-world setting, but the advantage of the medications studied in CORAL is that they are all now off patent. "These are drugs that patients can afford, that are inexpensive, that are easy to take, and that we can use to make sure they get treated to goal.

"If you can get your patients to be compliant, I think the need for renal-artery stenting will be very low, but there will still be situations where patients can benefit from renal-artery stenting."

Cooper and Bittl had no disclosures. Disclosures for the coauthors are listed in the paper.


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