If anything’s for certain, it’s that the medical community is uncertain about how to proceed with renal denervation in the aftermath of Medtronic’s (NYSE:MDT) high-profile clinical flop, but many agree that the field needs a serious injection of common sense before it proceeds.
In a coordinated Twitter meet-up last night, several of nephrology’s most social-media-savvy experts weighed in on Medtronic’s study results, chided studies without stringent controls and called for simpler, not sexier, approaches to treating hypertension.
In Medtronic’s SYMPLICITY-HTN3 study, the most robust trial to date to evaluate renal denervation (RDN) in treatment of hypertension, the treatment famously failed to produce better results than a sham procedure.
The shock was audible throughout the industry and the healthcare community. Recent medical association conferences devoted many hours and panels to discussing the trial and several of Medtronic’s rivals canceled or curbed their clinical programs.
Several medtech companies took harsh writedowns in their RDN assets and doctors alternated between calling the technology a dud and calling for more research to figure out why the SYMPLICITY-HTN3 didn’t match up to expectations set by the earlier HTN-1 AND HTN-2 trials.
Last night the Nephrology Journal Club hosted an online meeting of the minds, including some physicians that had participated in the HTN-3 trial and other RDN studies.
Participants discussed everything from Medtronic’s influence as sponsor of the study to the trial’s patient selection parameters and whether or not HTN-3 investigators had conducted the procedure properly. The 20 participants posted more than 260 Tweets over the course of 2 hours, ultimately seeming to come to little consensus regarding the appropriate fate for RDN.
Florida nephrologist Dr. Veeraish Chauhan chimed in toward the end of the session to offer his 2¢ on the future of RDN:
@kidney_boy S3 was the largest trial. I m gonna classify denervation under "the shit don't work" category of medical remedies
— Veeraish Chauhan, MD (@VeeraishChauhan) May 28, 2014
That sentiment resonated with several participants who "favorited" the Tweet, including Kentucky cardiac electrophysiologist and social media presence Dr. John Mandrola. The group was, however, also willing to entertain additional research with the technology. Perhaps RDN may do better, some suggested, with more thorough ablation of the renal nerves believed to contribute to hypertension.
On the the matter of RDN as a concept. I think THE issue is getting adeq technical ablation. EP docs know this is key. #NephJC
— John Mandrola, MD (@drjohnm) May 28, 2014
Or perhaps RDN may do better in patients with less severe forms of hypertension, rather than focusing only on patients who have already been prescribed several rounds of medication to no avail.
but perhaps for people with less severe hypertension? Maybe resistant hypertension is like metastatic cancer, not much you can do? #NephJC
— Joel Topf (@kidney_boy) May 28, 2014
I would be interested in a well designed trial n modest hypertension and seeing if it affected hard outcomes. #ThingsWeWillNeverSee #NephJC
— Joel Topf (@kidney_boy) May 28, 2014
Is this stupid: why does it only have to work in resistant HTN to be useful? #nephjc
— Paul Phelan (@paulphel) May 28, 2014
Or perhaps long-term data will show that the patients who received RDN instead of the sham procedure will see improvements in other outcomes, even if they didn’t see a reduction in blood pressure.
The question is will patient with equal BP get better hard outcomes (stroke CHF mortality) with renal denervation #NephJC
— Joel Topf (@kidney_boy) May 28, 2014
One thing that several participants did agree on was the need for more robust studies earlier in the game. Medtronic’s and other companies’ early studies generally don’t include controls or blinding, and some have reported results upward of 30 mmHg for their renal denervation systems.
They should require sham and blinded controls in earlier studies #NephJC
— Dr. Matt Sparks (@eAJKD) May 28, 2014
T3 biggest problem will be in investing in this again. i hope heart failure trials are sham and blinded #pleasedothisright #nephjc
— Dr. Matt Sparks (@eAJKD) May 28, 2014
Sham controls are needed, should have been thought of for SYMPLICITY 2. For proof of concept, S1 it was OK IMO for no controls #nephjc
— swapnil hiremath (@hswapnil) May 28, 2014
Aside/snark. Uncontrolled 'trial' is an oxymoron. #nephjc
— swapnil hiremath (@hswapnil) May 28, 2014
The group seemed largely to agree that the technology was resting on shaky ground, but some were ready to lean more toward non-RDN options for treating hypertension, such as through salt limitation or by opting for drugs already on the market.
@Kidney_dude Yes, as the recent Kaiser data showed, frequent visits, algorithmic care can ++ improve BP control. Simple, not sexy #nephjc
— swapnil hiremath (@hswapnil) May 28, 2014