Kidney Artery Stents Fail to Provide Greater Heart Help

A procedure to clear and prop open clogged kidney arteries didn’t offer a cardiovascular benefit to patients more than drug therapy, researchers said, underscoring the need to use medicines first to reduce heart disease.

The study released today builds on two previous trials that also found the procedure known as renal stenting was no better than aggressive drug therapy. Doctors cited flaws in the original research and continued to perform the procedures since clogged renal arteries have been linked to high blood pressure, kidney damage and long-term complications.

Deaths and heart and kidney complications were similar regardless of whether patients got Johnson & Johnson’s Palmaz Genesis stent or blood pressure and cholesterol-lowering therapy with drugs from AstraZeneca Plc and Pfizer Inc., according to the U.S. government-funded study presented at the American Heart Association’s annual meeting in Dallas. Stenting lowered blood pressure, though that didn’t translate into a heart benefit.

“People are doing renal artery stenting with the belief that it will help difficult to treat hypertension, multidrug resistant hypertension, all those categories,” said Robert Harrington, chairman of the department of medicine at Stanford University and chairman of the AHA’s scientific sessions. “This suggests that it doesn’t work.”

The 10-year trial involved 947 patients who had moderately clogged kidney arteries and high blood pressure that wasn’t adequately controlled by two or more medications. After 3.5 years, 35.1 percent of patients given a stent plus more intense drug therapy died or suffered a complication from heart or kidney disease, compared with 35.8 percent given the drugs alone. Complications included heart attacks, strokes, hospitalization, worsening kidney disease and dialysis.

Stenting Futile

The study “establishes beyond a reasonable doubt that renal-artery stenting is futile for the target population enrolled in the study,” said John Bittl, from Munroe Regional Medical Center in Ocala, Florida, in an editorial accompanying the study in the New England Journal of Medicine. “The challenge remains for future trials of renal-artery stenting to identify a suitable target population for enrollment.”

The trial was funded by the National Heart, Lung and Blood Institute, Pfizer and New Brunswick, New Jersey-based J&J. The medicines used in the study were provided by New York-based Pfizer and London-based AstraZeneca. Renal artery stents are made by J&J, Abbott Laboratories, Medtronic Inc. and Boston Scientific Corp.

Not First

The findings don’t mean that no one should get a renal artery stent, said Michael Jaff, chairman of the Massachusetts General Hospital’s institute for Heart, Vascular and Stroke Care in Boston. Instead, it proves beyond a doubt that it’s not the right first treatment for people with clogged renal arteries.

“The medical regimen that was offered is inexpensive, most of it is generic, the compliance is good because it’s mainly once daily dosing, and it works,” he said in an interview.

Medicare, the U.S. government’s health insurance program for the elderly, is likely to review their coverage of the treatment based on the study’s results, Jaff said. A previous review several years ago found there wasn’t enough evidence to change coverage levels, he said.

About 100 million Americans have hypertension, and clogged kidney arteries known as renal artery stenosis is responsible for about 1 percent to 5 percent of those cases, Jaff said. Not everyone undergoes stenting, however, and many may not even be aware of the condition, he said.

A 2007 study showed stenting the cardiac arteries failed to ward off heart problems better than drugs.