Scott Webb (Host): Renal denervation is an innovative option for managing high blood pressure that's helping patients to deal with hypertension and, in many cases, reduce their number of daily meds. And joining me today to tell us more is Dr. Rajiv Tayal. He's the Director of the Cardiac Catheterization Laboratory and Structural Heart Program for the Valley Hospital.

 Welcome to Conversations Like No Other: Heart Care, presented by the Heart and Vascular Institute of Valley Health System in Paramus, New Jersey. Our podcast goes beyond broad everyday cardiac topics to discuss very real and very specific subjects that impact your heart health. We think you'll enjoy our fresh take. I'm Scott Webb. Thanks for listening.

Doctor, it's so nice to have you here today. I was telling you that I suffer from high blood pressure, and I take pills and try to keep that under control. But I want to learn more about renal denervation and what that is, RDN. So, how does it work to lower blood pressure?

Dr. Rajiv Tayal: It's an interesting question, and it's something that comes up more and more frequently in this day and age. Just taking a step back and looking at the world, you know, hypertension now affects over a billion people. And of those people, even on medications, only about one in five are adequately controlled. So, it is something that we're seeing more and more commonly. Maybe it's associated with diet, maybe the increasing prevalence of obesity, things like that. But essentially, you know, there is a subportion of people that, despite being on two, three, or four medications, still just can't seem to control their blood pressure. And obviously, that puts them at higher risks of having heart attacks, strokes, and all those other things.

So, renal denervation in a nutshell is a procedure where a catheter is placed into the renal artery. It's typically inserted from the artery in the leg, similar to a cardiac catheterization. And this catheter then emits radiofrequency signals, which ablate the nerves, those nerves surround the artery going to the kidney, and decreases their sensitivity. And so, basically when you look at hypertension in a nutshell, it's basically driven by the sympathetic nervous system. And so, you have afferent and efferent nerves or nerves that are going to and from the kidney. And what this does is it decreases the sensitivity of those nerves so they don't overreact to signals from the nervous system.

Host: Interesting. Yeah. And as a lay person, I'm going to hold on tight here and try to stay with you. I'm sure listeners will as well. But I'm with you so far. And, you know, you talked about the prevalence basically of hypertension, high blood pressure. So, who's a good candidate for this procedure, and is it meant for everyone with high blood pressure?

Dr. Rajiv Tayal: Technically, the current indications for this are people that have what we call resistant hypertension, which is typically defined as people being on three or more medications, and despite being on big doses of those medicines, really not being able to establish adequate control of their blood pressure. Meaning that a lot of their readings are still coming over that 140/90 mark, or that they're having significant variations in their blood pressure. You know, sometimes there are a number of people that we see that just cannot tolerate different forms of medications. They've tried two or three other forms and just either it makes them feel drowsy or they get dizzy.

And so, the candidacy for this procedure, I think, is something that we're just now kind of opening up. People that have had prior strokes or that are high risk for strokes or heart attacks that do have elevated blood pressures are all probably reasonable candidates for this.

Host: Yeah. Okay. So, how does it then compare, you know, how does RDN compare to taking daily blood pressure medications? Is the goal to ultimately, like, replace them, eliminate them? How does that work?

Dr. Rajiv Tayal: No, that's a great question. So, the goal is not to completely replace blood pressure medications at this point, I think, typically speaking, when you look at the data. So, this is something that's been around for decades. And actually, it was first done surgically back in the 1950s. But what we've seen is that, over the last 10 years, we've accumulated more and more data on it.

And so, you can expect to see a drop of your mean arterial pressure, meaning the average of your systolic and diastolic pressures by around 10 millimeters of mercury. So, the top number, that systolic blood pressure, should come down by around 15 millimeters of mercury. The bottom number, or the diastolic pressure, should come down around 10 millimeters of mercury. And typically, what we see is most people that are on three medications will probably be able to come down to one or two.

But most importantly, I think a lot of us don't know of very many people at all in the world that actually check their blood pressure in the middle of the night. But when you're looking at long-term studies, what you see is that a lot of people have very poorly controlled blood pressure throughout the day, and particularly at night. And obviously, like we talked about before, having high blood pressure increases your chances of having strokes and heart attacks, and a number of other adverse cardiovascular events. So, what we've seen is that by doing this, your overall percentage of time that your blood pressure stays controlled is much, much greater. So, it reduces your risks of all those things upfront very positively.

Host: This is anecdotal at best, Doctor, but it feels like many of us really only get our blood pressure checked like the once a year we go for our physical, that like wellness exam, right? And as you're saying, many folks are the taking their blood pressure at home and doing it more regularly, but they're not maybe waking up in the middle of the night to do it.

So ultimately, the goal with RDN, as you're saying, is to sort of have it more regulated throughout the day, throughout the night, maybe lower the medications. All sounds like good stuff, especially to my ears as someone who does have high blood pressure. Wondering what the procedure involves, what patients can expect on the day of treatment?

Dr. Rajiv Tayal: The hardest thing about hypertension in general is the fact that it has no symptoms, right? A lot of people are walking around and they have no idea that they have it, or to your point, they only get their blood pressure checked once or twice a year. And even then, you know, a lot of times in the doctor's office, I know when I go to the dentist office or anything like that, my blood pressure's elevated. What we've seen is actually telling people to get a blood pressure cuff. In this day and age, everything is more and more automated, so it's not like you have to pump the cuff up or anything. A lot of times, you just put it on your bicep area, it will do it automatically. You know, these things have become digitalized, so it's so easy that even my kids know how to do it in some instances.

But I think even more interestingly is the fact that a lot of these wearable smart devices, I think Apple, the next generation of their watch is coming out with some ability to check blood pressure. How accurate or how sensitive that is, we're not sure. But is it a step in the right direction? I think the answer's absolutely. And, you know, I think people are becoming more aware of health. They're making more conscious decisions about avoiding fast foods, super salty things. But I think, you know, encouraging people to take charge of their own health, just like you kind of check your weight every once and again at home, checking your blood pressure may not be a bad thing either.

Host: Right. So, let's talk about the treatment then, the day of, if you will. What can folks expect?

Dr. Rajiv Tayal: So, we bring people to the cardiac catheterization lab, kind of similar to what we do for cardiac catheterizations. We give them a little bit of what we call conscious sedation. So, the sedation is lighter than what you would have for a colonoscopy or an endoscopy or anything like that. But you are in kind of twilight sedation, so you don't really feel that much discomfort.

A catheter is introduced from the leg artery. And then, basically, we take a picture of the kidney arteries through that catheter, and then advance this device into the renal artery. Like I said before, it kind of emits this ablative signal. So, we treat different quadrants of the arteries in the kidneys. Typically, it takes about an hour from start to finish. And I'd say right now in this day and age, probably 70-80% of people go home the same day. A few people do want to stay overnight, just depending on their comfort level. And it's a relatively routine, very low risk, very safe procedure.

And so, that's one thing that we've seen over and over and over in the data, is people say, "Oh, can it make my kidney function worse? Can it hurt me?" And the overall answer is no. It's been proven to be one of the safest things that we've seen from a procedural standpoint that I think offers an exciting avenue to help a lot of people reduce their risks of cardiovascular events going forward.

Host: Yeah. As you say, obviously, it's a very safe-- I never have an expert on here who touts how unsafe something is. So, I assume that, you know, when we're talking about something like RDN, it's because it is safe, it is effective, but are there any side effects or risks at all?

Dr. Rajiv Tayal: Now, there have been some studies where a few people-- and we're not sure exactly who that is-- have been shown to be non-responders. There's really no adverse effects of the procedure or anything that necessarily happens bad, but sometimes it doesn't necessarily improve people's blood pressure off the bat.

The duration of which from when you have the procedure to when it actually takes full effect varies from person to person. So, it can happen, you know, as quickly as a week to two weeks after the procedure. Sometimes it takes two to three months. But in about 5% of the population, what we've seen is they've been termed non-responders. And so, currently, people are looking at whether they need to have a concomitant ablation of different arteries or nerves in the body, whether that's going to the liver or other surrounding structures.

Host: Sure. Right. As you say, maybe the worst side effect, if you will, is that it may not be effective or it may not be effective right away. But otherwise, I feel like this is one of those things that's been sort of theoretical. And now, that it's in practice and it's happening in real life, are you finding that, overall, it's pretty effective?

Dr. Rajiv Tayal: You know, to date, knock on wood, I haven't seen anybody that hasn't responded to the therapy that we've treated personally. The time course of which people have the maximum benefit seems to be right around that one to three-month mark. And so, a number of people that we've treated were on as many as five different medications and are now on two. Some have come down to one. But I think most people that have undergone it have been very, very happy and had no kind of procedural adverse events or any other issues related to it.

Host: That's great. Yeah. It makes me think here like, "Okay, is this permanent?" Right? I talked to all sorts of experts about, you know, if you get a knee replacement, "Am I going to need another knee at some point?" Right? So, is the effects, if you will, of RDN permanent or will patients have to go through, you know, sort of routine checkups or something?

Dr. Rajiv Tayal: So, typically speaking, it's a one-time, one-and-done kind of procedure. Some people that have been found to be non-responsive to the therapy have been brought back for a second one. But again, you're talking about 5% of those patients that are being treated. And sometimes when they do have a second treatment, it works better for them. But they're still trying to drill down and figure out who's going to respond, who's not going to respond before we even get into talking about the procedure to begin with.

Host: I knew I was going to learn a lot today from you, Doctor. I was like, I love new topics. It's my favorite thing about hosting, is learning from experts. So, I appreciate your time. I just want to finish up, you touched a little bit on the technology, how easy it is to check our blood pressure and maybe the future generations of smart watches and all of this cool stuff, cool tech. Just wondering, if you look into your crystal ball, do you foresee RDN really just changing the way folks manage hypertension, how you help folks manage their hypertension?

Dr. Rajiv Tayal: Absolutely. So in its current state, it's relatively new to the United States. It, again, has been done throughout Europe for over 10 years. Right now, it's relatively restricted in terms of who we're recommending undergo it until I think we understand the technology a little bit better. So, we are kind of saving it for people that are on multiple hypertensive agents that, you know, have a really hard time controlling their blood pressure.

I think in the future, whether that be in three to five years, have you, that it will be a frontline therapy for a lot of different people that may or may not want to take drugs or can poorly tolerate them. And I think the overall applicability of this technology to multiple patients will continue to grow as we look forward.

Host: Yeah. There's what I call the shaking head syndrome that I have when I host these, and I love when I'm listening to experts and I'm just shaking my head going, "Yes, you've done it!" You're changing things for yourself, for patients. You're changing the world. You're introducing new frontline treatments. Definitely a head shaker today. I love it. Thank you so much.

Dr. Rajiv Tayal: Thanks, Scott. I appreciate the opportunity.

Host: Thank you for joining us on this episode of Conversations Like No Other: Heart Care. We hope today's discussion on renal denervation has helped you to better understand this innovative option for managing high blood pressure. Remember, exploring new treatments with your care team is an important step towards taking control of your heart health. Be sure to subscribe, share this episode. And for more heart health resources, visit valleyhealth.com/heart.