I'm Aware That I'm Rare: Richard N. Channick, MD (PE Part 2)
Dr. Richard N. Channick discusses PE symptoms and treatment in Part 2 of 2 in his series on pulmonary embolism. He is the director of the Pulmonary Hypertension and Thromboendarterectomy Program at Massachusetts General Hospital in Boston. Dr. Channick diagnoses and treats patients who suffer from a variety of diseases of the pulmonary blood vessels, including PH and pulmonary embolism.
Hello, my name is Rich Channick. I’m a pulmonary critical care physician, Director of the Pulmonary Hypertension Program at Massachusetts General Hospital in Boston.
Today we’re going to go a little deeper into pulmonary embolism.
The symptoms of pulmonary embolism can range anywhere from mild chest pain, what we call pleuritic chest pain, typically where it’s a sharp pain often worse with a deep breath. It can very commonly present with acute shortness of breath, and the acute nature is important and may help to distinguish it from other lung issues.
When you’re out there, one second you’re fine, the next second you can’t breathe, that very sudden onset makes this much more suspicious for pulmonary embolism. In worst cases, the patient can have what we call syncope or pass out, and many patients with large pulmonary emboli present with a sudden episode of syncope.
The recommendations are for treatment duration depends on a couple of things. It depends on if this is their first clot or their second. If it’s the second clot, the recommendation is lifelong anticoagulation. If you’ve had one before, you’re going to need to be on a blood thinners for the rest of your life. If this is your first clot, and it’s what we call provoked, meaning there was a clear reason why somebody got the clot, they fractured their ankle or had a recent surgery, then that patient can stay on anywhere from three to six months and then potentially come off.
For patients who’ve had an unprovoked clot, meaning we don’t know why you got it, they’re in the gray zone, and we discuss duration of treatment. There may be some blood tests we can get to try to help determine so I can sit down with the patient and say, “Look, based on these readings in your blood, your risk at one year if we stop the anticoagulation of getting another clot would be let’s say 6%, and in five years 15%.” That’s based on equations we use based on the number of factors. Then in many cases it’s the patient’s decision. It’s very much an interaction we have with the patient.
After an acute pulmonary embolism, several things can happen. We think probably at least 80% of the time, if not more, the clot completely goes away. By six to eight weeks the body’s dissolved the clot, there’s nothing left, and the patient’s back to where they were at. In the remainder of the patients, a couple of different things can happen, and this is something we’re learning more and more about. This is something we call the post PE syndrome, which is a broad term, but it refers to patients who never quite get back to normal after they’ve had a clot. It’s pretty interesting because in some of those cases we can’t really find a reason for why they’re just not able to do what they used to do.
Some of it may be what we call deconditioning or maybe even fear. A patient who had a life-threatening event, a previously healthy person, they’re probably afraid of having another one. That may affect their overall quality of life and exercise capacity.
Then there’re the patients where the clots are still there. That’s probably anywhere from maybe in the 5 to 10%, where there’s some clots still left in the arteries of the lungs. They haven’t gone away, and they’ve actually formed scar tissue. As our clot gets older and older, it’s really no longer a clot. It’s scar tissue blocking the inside of the artery.
Whether that causes a problem for the patient depends on several factors, some of which we don’t understand, one factor being how big is it. If it’s just a little bit of a scar down in a tiny little blood vessel, then you’re probably not going to have any real problem with that. If it’s a big scar blocking several branches, well, that’s a patient who has a good chance of developing CTEPH. So some if it is size.
Then there probably are other complicated factors. Patients with certain inflammatory conditions are more at risk. There’s a number of things we don’t fully understand about why some people get CTEPH and some people don’t, so it’s an area of interest actually.
If there’s a concern about chronic thromboembolic disease, or chronic thromboembolic pulmonary hypertension in a patient, let’s say who had a pulmonary embolism and just never quite got back to baseline and is still limited, still doesn’t feel quite right, one needs to consider that this could be chronic thromboembolic disease and get the right imaging tests. The right imaging tests we feel is a ventilation profusion scan, a nuclear medicine test, easy to get and it’s a very sensitive test. If there’s even a little bit of clot left, the V/Q scan will show it, and it really is a good screening test. If the V/Q scan is normal, you’re not going to have CTEPH.
The other side of the coin is patients who present with pulmonary hypertension, in other words just shortness of breath, they’re found to have an abnormal echo, they get a right heart catheterization and they find that they have pulmonary hypertension, part of the workup of that is to rule out CTEPH.
It turns out that of those patients with CTEPH, about 30% of those patients never had a history of an acute PE. They presumably had one. They just didn’t know about it at the time. They just came with pulmonary hypertension, chronic shortness of breath. Unless you look for CTEPH in that patient, you’d never find it. That’s why in the diagnostic algorithm, the V/Q scan is right in there as a test one needs to order.
My name is Richard Channick and I’m aware that I’m rare.
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