Jenny Yang, MD - phaware® interview 546

The One Type of PH You Can Actually Cure

Dr. Jenny Yang dives into the rare but life-changing world of CTEPH, the only form of pulmonary hypertension that may be curable. From early warning signs to surgical options, this episode explains why ruling out CTEPH should be step one for any PH diagnosis.

My name is Jenny Yang. I am currently at UC San Diego. My background is in pulmonary and critical care. I did all of my training at UC San Diego and was exposed to pulmonary hypertension there throughout my training and really fell in love with the disease process of PAH and CTEPH. So, when I finished up my training, I decided that that's what I wanted to pursue with my career. I am currently still working at UC San Diego and focused on pulmonary vascular diseases, so I do some PAH and CTEPH with a really big focus on CTEPH and the different management options that we have for that now.

Today, I think it'd be a great opportunity to talk to you all a little bit more about CTEPH.

The most common way that a patient presents to us with CTEPH is after they get an acute pulmonary embolism. The vast majority of patients have had a prior PE, or pulmonary embolism, and afterwards they don't recover back to how they were feeling. After three to six months or so of being on blood thinners most people should feel back to how they were before that PE, but a small percentage of people won't. Then they'll get worked up by their local doctors and eventually will get referred to us.

It is a pretty rare disease, CTEPH. It only happens in about probably 3% or so of patients after PE. So, sometimes the journey and process of getting to us can take a while, but hopefully most people will find their way to a CTEPH center and can get the appropriate workup and then treatment for that.

I think there's more awareness of the disease, which has definitely helped improve provider's awareness, patient's awareness of what CTEPH is and that if they're not feeling back to normal that something is going on and something is wrong. A lot of CTEPH centers have popped up all over the country now. The important thing is that you go to a center that has experience with this disease.

CTEPH is unique in that it is potentially curable. It's sort of the only form of pulmonary hypertension that is potentially curable. Anyone who gets a diagnosis of pulmonary hypertension, I think it's important to rule out CTEPH as the first step because if you miss it, you sort relegate someone to being on medical therapy for the rest of their life when potentially either a surgery or other procedures could cure or prevent the need for any further medications.

The process of getting to that diagnosis can be tricky. Our screening test of choice is something called a ventilation profusion scan. It's not widely available everywhere and it's seen as an outdated technology in certain places, but it really provides a good initial test to know if someone might have CTEPH or they won't. It's essentially a test where it looks at blood flow in the lungs and if it looks like your blood flow is completely normal, then it basically rules out CTEPH and that's not your diagnosis within pulmonary hypertension. But if it's abnormal, then it's a possibility and it means that you need further testing and confirmatory testing to see if you do have CTEPH.

Once they're referred to our center for possible CTEPH, we have this sort of dedicated pathway that they'll go down. They'll meet us in clinic and they get a slew of testing. They'll get an echocardiogram, a chest X-ray, the V/Q scan, and then also a right heart catheterization to assess their hemodynamics and a pulmonary angiogram, as well. We meet as a group once a week, our multidisciplinary CTEPH meeting with pulmonologists, our cardiothoracic surgeons, our BPA interventionalists and chest radiologists, and we all review imaging and history together to make sure that we think that surgery is the way forward.

Once we've decided that surgery is the way that we're going to go, most of these patients already have a surgical date penciled in for them since a lot of them are coming from across the country. Then, they will get admitted and go through surgery. The surgery itself, it's a long surgery. It's about eight to 10 hours, an open heart surgery.

Most of these patients, they spend about an average of 10 days or so in the hospital. I think the soonest that we've had patients get discharged is on day six after surgery. Most of these patients will fly through and the recovery after they get discharged is about one to two months for that sternotomy to really heal. Then, a lot of them can get back to their lives and feel much better than before and are able to get back to doing marathons, hiking, rock climbing, and sort of all the things that they couldn't do before surgery.

We do roughly 180 surgeries a year or so. Then, we've also started a balloon pulmonary angioplasty program about 10 years ago now. That is really reserved for patients who aren't surgical candidates or who still have some residual pulmonary hypertension after surgery. So, we see those patients as well on top of it. It ends up still being quite a lot of patients that we're seeing.

Even though there are other centers that are starting all over the country, there's still a big need for CTEPH care and I think a lot of patients that those other centers are potentially serving are ones that couldn't travel or wouldn't travel. We're one center and one part of the country and can only see sort of those patients that can travel, so the select few. There are probably thousands of CTEPH patients that we don't see and still need care.

There's definitely a lot of questions and some people will come in with preconceived notions that they don't want surgery or they don't want the balloon pulmonary angioplasty procedure. There's a lot of information online and in support groups that they get that information already and so they can come in with those ideas. When we meet them in clinic and when we talk with them after they complete all their testing, if they have disease that we think is technically operable, we really try to explain to them why surgery is the best option for them.

If they really don't want surgery, we won't, obviously, push them towards it, but we'll explain what the potential other options are and sort of the pros and cons of going that way as opposed to surgery. But we've had people definitely who have had what we consider to be operable disease who ended up going with balloon pulmonary angioplasty for personal reasons and still do well, and that sort of fits their schedule and their reasoning better and they're able to travel back and forth to San Diego easily. That is with the balloon pulmonary angioplasty procedure. It does take multiple trips out to San Diego as opposed to the surgery, which it's a longer visit, but it's sort of one time you get the surgery, the hospital stay and then you're done. But a lot of it is explaining and the reasoning behind why we recommend one procedure or the other, and then sort of having that shared decision-making process.

Let me give you a brief overview of how PTE surgery works. So it's an all-day surgery. It's eight to 10 hours, and so it's an open-heart surgery, and so they go through the breastbone and really sort of the key tenets of the surgery is that we will do the endarterectomy on both sides. Even when it looks like there might only be disease on one side, a lot of times we'll find disease on both sides and it requires cardiopulmonary bypass. Then, the unique part of the surgery is that it requires this deep hypothermic circulatory arrest. So, we'll cool patients to about 18 to 20 degrees Celsius. Then, when they have adequately been cooled, we completely stop blood flow. So, they have this circulatory arrest period and that is essential so that the surgeons can see exactly what they are dissecting out in the pulmonary artery so that they have this completely bloodless field.

We limit that period to about 20 minutes or less. Then, they'll allow blood to recirculate and then they'll do the same thing again for the opposite pulmonary artery. After that's completed, then they slowly rewarm the patient and then usually by the mid to late afternoon they're done with surgery and are closed up. But that's sort of the unique part of that surgery.

Now, I'll do the same for balloon pulmonary angioplasty and why we may proceed with balloon pulmonary angioplasty rather than the PTE surgery. With balloon pulmonary angioplasty, we work with our interventional cardiologists for. It requires a multiple trips out to San Diego to perform an adequate number of balloon pulmonary angioplasties. Essentially, what happens is it's done in the cardiac cath lab and patients will start with a right heart cath, very similar to sort what is done during their diagnostic workup for CTEPH, but this time we use femoral access. All of the access is through the groin and a larger sheath is placed so that through there then all of the balloon pulmonary angioplasty equipment can be placed.

It takes about roughly two hours or so. The procedure starts with a right heart cath and measuring the pressures. Then, we do a setup for the balloon pulmonary angioplasty. During the procedure, essentially we perform selective angiography. In select areas of the lung where we think that there's disease, which is usually we start with the lower lobes, we will inject contrast to highlight what the vasculature looks like and identify target lesions.

Once those target lesions have been identified, we'll pass a wire through that lesion and then inflate a balloon. The goal is to sort of push aside that disease, that clot, and restore blood flow. The goal of the BPA procedure is different than PTE. Since nothing is being removed, it's simply pushing the disease aside to restore blood flow. That's one of the reasons why we really prefer PTE is because we're actually physically removing a lot of that scarred and disease, if possible.

So, BPA is really reserved for the patients who have disease that's too distal and that cannot technically be operated on or patients with residual pulmonary hypertension after PTE surgery. That is really it's for disease that's too distal for our surgeons to remove. People can still have residual pulmonary hypertension after PTE surgery.

What we've come to realize over the last several years is that CTEPH is this spectrum of proximal and distal fibrotic obstructive disease, but as well as this microvasculopathy component. There may be patients who may benefit from multiple modalities of treatment. If it looks like patients have what is considered to be operable disease, we would still recommend PTE surgery knowing that they may potentially still need BPA afterwards because it looks like they may have some disease that's quite distal that our surgeons won't be able to get everything out.

Even when the endoterectomy looks like it was very successful in terms of being able to achieve a lot of that clot out, that component of microvasculopathy can what we think contributes to some of the progression of symptoms and residual pulmonary hypertension after PTE surgery. It does happen that patients will still have symptoms and some degree of residual PH afterwards and may need either BPA medical therapy or oftentimes a combination of both.

Riociguat is the only FDA approved medical therapy for inoperable CTEPH or residual PH after PTE. We typically reserve it for patients who are not operable candidates or who have residual PH after PTE surgery. If patients are going towards BPA with sort of pretty moderate to severe hemodynamics, it's become standard of care that patients will get on Riociguat to try to improve their hemodynamics going into BPA. It's been shown to reduce complications of the BPA. So, that's really sort of the main role of Riociguat and medical therapy in general is for patients who aren't surgical candidates or prior to BPA to help reduce complication rates. We do see a lot of Riociguat use before surgery, and we don't have any data to support the use of medical therapy as a bridge to PTE surgery, but it does happen. It's still unclear whether or not that is helpful or not and that data just doesn't exist yet.

We had a patient prior to his pulmonary embolism, was a very avid ice climber and hiker and would sort of hike all over the state, all over the country and doing these very amazing trips to tops of mountains. He had a blood clot and afterwards was really unable to do a lot of his normal hiking and really even just walking up a hill started to become taxing for him. This had a huge impact on his quality of life and the things he enjoyed to do. He came to us and had PTE surgery. He lives not too far from us. About probably 200 miles or so. About six months later, he came for his post-PTE visit and ended up biking his way down from his home to San Diego and felt great. He had no limitations on his bike ride. At that visit sort of told us that he'd been back to hiking again.

Really at two months is when we sort of lift a lot of our sternotomy precautions. He had already started hiking. At that six month mark, he was doing so well that he got the green light to go back to ice climbing and rock climbing. I think he climbed Mount Whitney and sort of all mountains around California and has now sort of expanded that to the Canadian Rockies and is back sort of living his dream, his life.

That part of the job is incredibly gratifying and he sends us pictures routinely of all the various trips that he's done. But that's really what makes CTEPH I think so unique and that people are able to be completely cured. He is not on any medical therapy, has never needed any procedures afterwards and is back to sort of doing what he wants to do with his life.

Thank you for listening. My name is Jenny Yang and I am aware that my patients are rare.

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