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Treating Kidneys With Radio Waves May Ease Tough-to-Control Hypertension

Treating Kidneys With Radio Waves May Ease Tough-to-Control Hypertension

Our Review Summary

At least  this story was better than the Toronto Star story, which led, “In what’s being described as a potential public health miracle….” and better than some recent Star Tribune stories on renal denervation.

But the flaws we point out are not difficult to address.


Why This Matters

There are more than 7 million Americans who have hypertension that is resistant to drug therapy.  That resistance may be the result of inadequate drug dosing, incorrect drug combination, poor compliance and adherence or underlying physiology.  A new approach for patients with truly resistant hypertension is clearly needed.  Renal denervation is not new or novel.  A new device that reduces the risks of the original procedure may bring the approach to many more patients if it truly works, is durable and is not associated with kidney damage. While preliminary studies appear to be promising, the true test of multiyear durability has yet to be demonstrated.



Does the story adequately discuss the costs of the intervention?

Not Satisfactory

No discussion of costs.  This approach is not going to be cheap.

Does the story adequately quantify the benefits of the treatment/test/product/procedure?


The story adequately reports what the researchers reported about decline in systolic blood pressure.

Does the story adequately explain/quantify the harms of the intervention?

Not Satisfactory

It’s not sufficient to simply act as stenographer when study authors say “the procedure is safe as well as effective.” In fact, a careful review of the actual journal paper contradicts the safety statement. One subject in the crossover group suffered a renal artery dissection (tear) during placement of the guide catheter that required urgent repair. Not important enough to report?

And it certainly isn’t adequate to quote from a news release that “participants’ kidneys were not damaged or functionally impaired.  We also found no ill effects on long-term health from the procedure.”  Would most blood pressure experts consider 6-12 months as “long-term health”?

Can a procedure be proclaimed “safe” in the hands of one experienced team?  What might the learning curve be for this approach?

These are not merely academic questions when a researcher – and a story – proclaim a tiny study as proof of safety.

Does the story seem to grasp the quality of the evidence?

Not Satisfactory

There was no critical analysis of the evidence that was reported – no discussion of the limitations of drawing conclusions from the experience of one team reporting on 35-82 patients (depending on whom you count in this study).

No discussion of the issue that lowering blood pressure is a surrogate for reducing cardiovascular risk.  So letting the researcher get away with saying the procedure is “safe and effective” is incomplete and misleading and lacking necessary context.

The study design is not well described in the story.  There were actually 190 entered into the study with 106 actually randomized.  Importantly, 36 of the enrolled subjects were removed from the study during a period when their compliance to medication was closely observed, pointing to the importance of compliance and adherence.  52 subjects were assigned to have the procedure performed while 54 acted as a control group for the first 6 months of the study.  They then went on to have the procedure performed.  Importantly, only 35/54 actually went on to the second part of the study and received the procedure.  9/54 were ineligible for the procedure at 6 months because their blood pressure dropped below 160mm Hg systolic. And finally, the story really did not focus on the fact that all the subjects continued on drug therapy despite the qualifier by Dr. Singh.  The headline of the story should have been “Treating Kidneys with Radio Waves and Drugs May Ease Tough to Control Hypertension.”

Does the story commit disease-mongering?


No overt disease mongering at play here.

Does the story use independent sources and identify conflicts of interest?


Medtronic funding  was disclosed.

There was an independent expert who provided some needed balance – although that expert was not quoted about any real critical analysis of the evidence.

Nonetheless, enough to get a satisfactory score.

Does the story compare the new approach with existing alternatives?


The independent expert quoted provided important reminders about “so many things that go into getting blood pressure under control” – lifestyle, medications, adherence, etc.

Does the story establish the availability of the treatment/test/product/procedure?

Not Satisfactory

The story explained that the procedure is used in other countries but not yet approved in the US.

However suggesting it is used in other countries doesn’t really provide the reader with enough information.  Here is what the UK’s National Institute for Health and Clinical Excellence (IPG418 Percutaneous transluminal radiofrequency sympathetic denervation of the renal artery for resistant hypertension: guidance ) had to say about the approach:

“Current evidence on percutaneous transluminal radiofrequency sympathetic denervation of the renal artery for resistant hypertension is from limited numbers of patients, but there is evidence of efficacy in the short and medium term. There is inadequate evidence on efficacy in the long term; this is particularly important for a procedure aimed at treating resistant hypertension. The limited evidence suggests a low incidence of serious periprocedural complications, but there is inadequate evidence on long-term safety. Therefore this procedure should only be used with special arrangements for clinical governance, consent, and audit or research.”

These evidence-based questions will have some impact on availability – whether in other countries or in the US.  And the story should have dug a bit deeper.

Does the story appear to rely solely or largely on a news release?


The story did pull a researcher quote from a journal news release, but there’s no evidence that it relied solely or largely on a news release.

Total Score: 5 of 10 Satisfactory

Comments (1)

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Gary Schwitzer

December 18, 2012 at 4:12 pm

In a post on his CardioBrief blog, Larry Husten wrote:

Excitement about renal denervation has been growing in recent years. At least some of the optimism may well be warranted. But, for now, the greatest danger is hype. Here’s the #4 item on the AHA’s list, released just this week, of the top advances of 2012:

“Disconnecting” the kidneys might be the key to treating high blood pressure

What does that mean, “the key to treating high blood pressure?” As an invasive procedure, renal denervation will never be more than a important therapeutic option after lifestyle and polypharmacy have failed. I applaud the AHA for highlighting this important new technology, but I think it should have used more cautious wording.

Get ready for much worse. Gullible or naive reporters and editors have already fallen into the trap. Here’s the headline and opening sentences of a story that appeared earlier today in

Zapping kidneys with radio waves could cure high blood pressure, study finds

In what’s being described as a potential public health miracle, a new study shows that zapping the kidneys with radio waves can safely and dramatically lower blood pressure.

“It makes one dizzy to think about the next set of benefits that follow,” said Dr. Clyde Yancy, head of cardiology at Chicago’s Northwestern University.

This is almost a textbook example of how science and medicine stories should not be reported. It’s important to activate your BS detector whenever you see words like “cure” and “miracle” in a health story. Renal denervation is not a cure and it’s not a miracle. If things work out, it may represent a welcome and significant advance for some patients with resistant hypertension.