Scott E. Olitsky, MD - phaware® interview 486

Sep 17, 2024

In this episode, Dr. Scott Olitsky, the Global Center of Excellence Outreach Director for Cure HHT, discusses hereditary hemorrhagic telangiectasia (HHT), a genetic disease characterized by abnormal blood vessel development. HHT can cause bleeding in various parts of the body, with nosebleeds being the most common symptom. In some cases, HHT can lead to the development of pulmonary arterial hypertension (PAH). Medications that dilate blood vessels can worsen bleeding in HHT patients. Dr. Olitsky shares his personal connection to HHT and PAH and highlights the efforts of Cure HHT to improve diagnosis and treatment options for patients.

My name is Dr. Scott Olitsky. I am currently the Global Center of Excellence Outreach Director for Cure HHT, which is the International Foundation for Hereditary Hemorrhagic Telangiectasia. I also happen to be an HHT patient and a caregiver to someone in my family with pulmonary arterial hypertension.

HHT is a genetic disease. It's autosomal dominant, which means that statistically 50% of all children born to a parent with HHT will have the disease. It's a disease of abnormal blood vessel development. So normally, arteries connect to veins in the body through a system of capillaries, very fine blood vessels. In HHT, the capillaries are missing, so the arteries connect directly with the veins. Because of this connection, the area where they do connect is prone to bleeding. So we see bleeding in certain sites where these abnormal blood vessels form. Typically, they form on the skin, on the mucosa of the lips, the mouth, the tongue, the nose most notably, the GI tract. Larger tangles of blood vessels can also occur in places like the lung and brain.

So because of these abnormalities, we tend to bleed. The most common sign or symptom of HHT is nosebleeds. About 90% of patients have nosebleeds. These nosebleeds can range from anything from a minor inconvenience to being life-threatening.

There are two forms of PH that tie into HHT. By far, the most common type occurs when these arteriovenous malformations, AVMs, form in your liver. Because of this, we can have shunting through our liver that shunts blood back to the heart before it has a chance to go to the rest of the body. This overflow of blood back into the heart is also pumped into the lungs. This can lead to secondary changes in the pulmonary artery system, which leads to pulmonary hypertension. That occurs in about 20% of patients with HHT. Far less common is the 1% of HHT patients who develop PAH, precapillary pulmonary hypertension, which behaves just like idiopathic or other forms of hereditable PAH.

So as anybody listening this knows PAH is a difficult disease. Some of the drugs have some side effects that are potentially very problematic for patients, but for HHT patients in general, at this point, most but not all of the PAH drugs work by dilating blood vessels. This is problematic in HHT patients, because these blood vessels that are dilated include these abnormal blood vessels that we have. So most patients with PAH related to HHT see a significant increase in their bleeding, whether it be from their nose or very likely their GI tract, which causes iron deficiency and anemia. Of course, anemia on top of an already stressed heart is very problematic for a patient with pulmonary hypertension.

By far, the most common problem patients with HHT have are nosebleeds, and they tend to run in families. Now, 90%, as I mentioned, have nosebleeds, but 10% don't. So the fact that a family member with known HHT in the family doesn't have nosebleeds, absolutely does not mean that they don't have HHT. That's very important, because these tangle of blood vessels that occur in the lung or the brain make people susceptible to stroke. We know that if you're properly screened, this risk can be maybe not entirely eliminated, but very close to it. So screening for people with HHT and these developments is very important.

The most common issue that families will find is that multiple members of the family have nosebleeds. In many families that is a source of worry, but in HHT patients, we live with nosebleeds every day, multiple times a day. So many HHT patients don't really think of these common nosebleeds as being a problem. They don't think of it as being a potential sign of a disease. So one family member may have more nosebleeds than the other, but they've grown up for generations seeing this. But it's an important point because we know many patients with PAH may be on anticoagulants, they may be on oxygen, which makes their nasal mucosa more prone to bleeding, and so they may have nosebleeds, and that's not uncommon in the PH community. However, in those patients whose family members also experienced nosebleeds, this might be a warning sign that you should be looked at with a thought that HHT may be running in your family.

HHT's diagnosis is made clinically, something called the Curacao criteria. There are four criteria. If you meet three of them, you have definite HHT. Two criteria, possible HHT. There's also genetic testing that can be done, which a mutation can be found in about 90 to 95% of patients. So generally what we suggest is that if a patient is concerned about potentially having HHT, they should see somebody who's familiar with the disease and see if a clinical diagnosis can be made. Generally, once the diagnosis is made, or if the diagnosis is possible, genetic testing is done. There are several mutations that cause HHT. There's one in particular which has a higher risk to develop PAH, then the genetic testing can be performed, confirm the diagnosis, also confirm the actual mutation.

This is important because that mutation can then be checked for another family. So what we recommend and our international guidelines recommend is that a patient with a clinical diagnosis be tested, the mutation be found, and then all members of that family should be genetically tested for that mutation. HHT does not skip generations. If you have the gene, you have the disease. So it's important to know that.

I've been involved with CureHHT for about two decades. I've been on their board for many years. I've known about my own disease since the time I was four or five. Didn't really think much about it. There wasn't a whole lot of treatments when I was younger. When I was in medical school, I remember going through the pathology textbook and seeing this disease and remembering this is what runs in our family. So I've been involved with HHT for a long time.

As I mentioned, I have a personal connection to PAH. About 20 years ago, I had a cousin who was running marathons, Ironman races, and then all of a sudden started losing her exercise tolerance, misdiagnosed with exercise-induced asthma. At one point, couldn't walk down a city block. I'm sure a story that's very familiar to many PAH patients searching for that diagnosis. She was given the diagnosis, was given a very grim prognosis at the time, was put on some of the only medications available at the time and has done very, very well. That brought my awareness to what pulmonary arterial hypertension was and how it's tied to HHT. Fast-forward to about six years ago, I have a daughter who was experiencing similar symptoms and was eventually diagnosed as well. So I've seen the delays in diagnosis. I've seen the issues with some of the medications and how they affect people with HHT.

At CureHHT, we talk about three goals, find, treat, cure. So we're trying to find patients with HHT so we can help treat them and eventually come up with a cure for the disease. We've been getting some terrific medications on board for patients. We're doing clinical studies to help nosebleeds, bleeding in general. We've set up international guidelines, so we really feel like we're getting places, but still, we estimate only 10% of patients with HHT are diagnosed.

My personal connection, of course, comes into play here. I know that there are patients. I've helped identify patients with PAH who have HHT, and as I mentioned, their nosebleeds were thought secondary to their anticoagulants, maybe the oxygen they were on. So in order to help find those patients, help treat those patients and come up with some new therapies for patients with HHT, whether that be the best PAH medication in light of their HHT, or helping to get them on medications to control the bleeding that occurs because of the medications they're on for their PAH.

We want to find those patients, and I think it's very important. Again, patients who are experiencing nosebleeds with PAH, don't just chalk it up to your medication or your oxygen therapy. Think about is there somebody in your family who has frequent nosebleeds, GI bleeding, history of an early stroke? These could all be signs that you may be a family member with both HHT and PAH.

Thanks for listening. My name is Scott Olitsky, and I'm aware that I'm rare.

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