A patient's guide to CTEPH
CTEPHA Cardiologist's Guide to Chronic Thromboembolic Pulmonary Hypertension
Why some old lung clots never clear, how that strains the heart, how CTEPH is found, and how surgery, balloon procedures and medicine treat it.
2 to 4%
is roughly how many people develop CTEPH after a pulmonary embolism
Up to 1 in 4
people with CTEPH have no known history of a clot at all
3 months
on a full-strength blood thinner, at least, before testing for CTEPH starts
More than 9 in 10
patients are alive at three years with treatment at an expert center
Most blood clots in the lungs dissolve. You get a pulmonary embolism, you go on a blood thinner, and over the following weeks your body breaks the clot down and clears it out. That’s the usual story, and it’s a good one. CTEPH is what happens when that clearing doesn’t finish. A piece of the clot stays behind, hardens into scar tissue, and permanently narrows the lung arteries.
This is the explanation I give patients who’ve been told they have CTEPH, or who are still short of breath months after a clot and want to understand why.
What it is
What CTEPH is
CTEPH stands for chronic thromboembolic pulmonary hypertension. Let me take that apart, because the name tells you the whole story.
Chronic
The clot has been there a long time and has stopped behaving like a fresh clot.
Thromboembolic
It starts with a blood clot.
Pulmonary hypertension
High blood pressure in the arteries of the lungs, which are separate from the arteries that carry the blood pressure a cuff measures on your arm.
The sequence starts with a pulmonary embolism. Tap through the five steps to see what usually happens to the clot, and what happens in CTEPH.
Step 1 of 5
After a pulmonary embolism, a clot sits in a lung artery
You get a pulmonary embolism, a blood clot in the lungs, and you go on a blood thinner.
CTEPH is uncommon after a pulmonary embolism. That sounds small, and it is, but pulmonary embolism is common enough that the total number of people affected is meaningful.
of people who’ve had a pulmonary embolism develop CTEPH, roughly.
is how doctors classify CTEPH, its own category, because it has a mechanical cause and, unlike most other kinds of pulmonary hypertension, a potential cure.
The right heart
Why it strains the heart
To understand why CTEPH makes people sick, it helps to picture the right side of your heart.
The right ventricle is a thin-walled pump built for an easy job. It pushes blood a short distance into low-pressure lung arteries. It was never designed to push against high pressure.
When old clots narrow those lung arteries, the pressure inside them climbs, and the right ventricle has to work much harder to force blood through. For a while it manages by thickening and enlarging. Over months and years, though, that strain wears it down, and the right side of the heart begins to fail. That failing right heart is what produces the breathlessness, the fatigue, and eventually the leg swelling. The disease is in the lungs, but the organ that gives out is the heart.
Two problems rolled into one
There’s a second layer to this that surprised researchers when they found it. CTEPH isn’t only about the big clots you can see on a scan.
The big clots you can see
The old, organized clot you can see on a scan, narrowing the lung arteries.
The small vessels you can’t
The small vessels of the lung, the ones too tiny to image, develop their own disease over time, a remodeling that raises resistance even in parts of the lung the clots never reached. That’s part of why some people still have high pressures after the visible clot is surgically removed, and it’s why we think about CTEPH as two problems rolled into one.
Why do some clots refuse to clear?
Nobody knows for certain why some people’s clots refuse to clear. The leading suspects are chronic low-grade inflammation, a clot-dissolving system that doesn’t work as well as it should, and underlying differences in how a person’s blood clots. It’s an area of active research, and for most patients we can’t point to a single reason.
Who is at risk
What raises the risk
The biggest risk factor
Having had a pulmonary embolism, especially one of these
- A large one
- A large pulmonary embolism.
- A recurrent one
- A pulmonary embolism that has happened more than once.
- An unprovoked one
- One that struck with no obvious cause.
Conditions that shift the odds
A handful of specific conditions make CTEPH more likely.
- Spleen removed
- Having your spleen removed raises the risk.
- Certain long-term implanted devices
- Such as older pacemaker leads and shunts.
- Past bloodstream infections
- Tied to indwelling lines.
- Chronic inflammatory conditions
- These play a role.
- Antiphospholipid antibodies
- A blood-clotting quirk found in about 1 in 10 patients.
- High factor VIII
- Persistently high levels of a clotting protein called factor VIII.
You don’t need any of these to get CTEPH, and having one doesn’t mean you’ll get it. They just shift the odds.
Up to a quarter never had a known clot
One of the trickiest things about CTEPH is that up to a quarter of people who develop it have no documented history of a clot at all. Their pulmonary embolism was either silent or missed, and CTEPH is the first sign anything was ever wrong. That’s a big reason the diagnosis gets delayed.
Symptoms
The symptoms, and why they hide
The main symptom of CTEPH is shortness of breath that slowly gets worse, especially with exertion.
Early on
You might notice
- The stairs
- You’re winded climbing a flight of stairs you used to take without thinking.
- A walk
- You can’t keep up on a walk.
- Fatigue
- Fatigue is common.
As the right heart struggles more
- Lightheadedness
- Feeling lightheaded.
- Swelling
- Swelling in the legs and ankles.
- The belly
- Sometimes a feeling of pressure or fullness in the belly.
Call 911
In pulmonary hypertension, fainting and chest pain can mean the right heart is failing
- Fainting
- Passing out.
- Chest pain
- Pain or pressure in the chest.
- Coughing up blood
- Blood when you cough.
- Breathing
- Shortness of breath that suddenly gets worse.
Why they hide
The problem is that every one of those symptoms creeps in gradually and looks like something ordinary.
| What you notice | What it gets blamed on |
|---|---|
| Getting winded on the stairs | Age, weight, or being out of shape |
| Fatigue | Stress or poor sleep |
Because CTEPH develops over months to years rather than striking all at once, and because it’s uncommon, the diagnosis is frequently missed for a long time.
The clue I want people to remember
The most useful clue is breathlessness that persists or worsens in the months after a pulmonary embolism. That is not normal, and it deserves a real workup rather than a shrug about deconditioning.
Tests
How we diagnose it
Before we even start looking for CTEPH, one condition has to be met. You need to have been on a full-strength blood thinner for at least three months.
That waiting period gives fresh clot the time it needs to dissolve, so that anything still blocking the arteries afterward is the old, organized kind that defines CTEPH. Testing too early can’t tell the two apart. Once that box is checked, the workup follows a clear order.
- First, 3 monthson a full-strength blood thinner
- V/Q scanthe best screening test
- CT pulmonary angiogramshows the actual changes
- Right heart catheterizationconfirms the diagnosis for certain
Ventilation-perfusion (V/Q) scan
It uses small amounts of a tracer to compare where air goes in your lungs with where blood flows. In CTEPH, blood flow is blocked in patches that airflow reaches normally, a pattern we call a mismatch. The most useful feature of this test is what a clean result tells us. A normal V/Q scan effectively rules CTEPH out, which is why we reach for it first.
CT pulmonary angiogram
If the scan points toward CTEPH, a CT pulmonary angiogram, a detailed CT scan of the lung arteries with contrast dye, shows the actual changes. In chronic disease these look different from a fresh clot. We see webs and thin bands stretched across the vessels, ring-like narrowings, and arteries that have closed off completely. These findings also help the surgical team judge how reachable the disease is.
Right heart catheterization
A thin catheter is threaded through a vein into the right side of the heart and the lung arteries to measure the pressures directly. Many patients also have a catheter-based pulmonary angiogram, which maps the disease in fine detail so the team can plan the right procedure.
What the catheter has to show
CTEPH requires a mean pulmonary artery pressure above 20 mmHg with a normal downstream wedge pressure, the combination that proves the problem sits in the lung arteries themselves rather than backing up from a weak left heart.
Treatment
How we treat it
CTEPH treatment is a team sport, and the reason I keep stressing expert centers is that the best outcomes come from a group of specialists looking at each case together.
There are three main tools, and many patients use more than one over the course of the disease.
A blood thinner for life, for everyone
Everyone with CTEPH stays on a blood thinner for life, no matter which treatments they have, because the underlying tendency to clot doesn’t go away.
Surgery to remove the clot
The treatment of choice, and the only one that can cure CTEPH, is an operation called pulmonary thromboendarterectomy, often shortened to PTE or PEA. A surgeon opens the lung arteries and carefully peels out the old, organized clot along with the scarred lining it’s grown into. It produces the biggest gains in symptoms and survival of anything we offer.
Balloon procedures for deeper disease
Not everyone can have the surgery. For them, balloon pulmonary angioplasty, or BPA, is a strong option. It works like a heart-artery angioplasty, threading a catheter with a small balloon out to the narrowed vessels and gently widening them, one session at a time over several visits. BPA also helps people who still have high pressures after surgery.
Medication
A medication called riociguat is approved for CTEPH that can’t be operated on, or for pressures that stay high after surgery. It relaxes and opens the lung arteries, which lowers the pressure the right heart works against and improves how far patients can walk. It’s the drug backed by the strongest trial evidence in this setting. Medication doesn’t remove the clot, so it works alongside the procedures rather than replacing the surgical evaluation.
is the risk of dying from the surgery when it’s done at a high-volume center. That’s remarkably safe for such a major operation.
of patients have disease that sits too far out in the smaller branches for a surgeon to reach, or other factors that make an operation too risky.
Which path fits
Every person diagnosed with CTEPH should be evaluated for whether they’re a surgical candidate. That assessment comes first, before any other treatment is chosen. Answer the two questions to follow the paths.
Every path on this map, with the treatment that goes with each one.
Step 1, for everyone
Can a surgeon reach the old clot, and is the operation safe for you?
Whether you’re a candidate depends on where the disease sits in the lung arteries, and on whether other factors make an operation too risky. You don’t decide this one alone. The team at an expert center makes the call.
Step 2, after surgery
After the operation, do the lung pressures stay high?
About a quarter of people who have the surgery still have some residual pulmonary hypertension afterward.
Surgery
Pulmonary thromboendarterectomy (PTE or PEA)
Path: a surgeon can reach the disease, and the pressures come down afterward.
The treatment of choice, and the only one that can cure CTEPH. For the right candidate it can restore near-normal lung artery pressures. Follow-up at an expert center continues after treatment, and you stay on a blood thinner for life.
Surgery, then more help
Balloon pulmonary angioplasty, riociguat, or both
Path: surgery, and some pulmonary hypertension remains afterward.
This is where balloon procedures and riociguat come in. Balloon pulmonary angioplasty helps people who still have high pressures after surgery, and riociguat is approved for pressures that stay high after surgery. You stay on a blood thinner for life.
No surgery
Balloon pulmonary angioplasty, riociguat, or both
Path: the disease is out of a surgeon’s reach, or an operation is too risky.
Balloon pulmonary angioplasty widens the narrowed vessels one session at a time over several visits. Riociguat is approved for CTEPH that can’t be operated on. Medication doesn’t remove the clot, so it works alongside the procedures. You stay on a blood thinner for life.
The team of specialists at an expert center looks at each case together and sets your plan. Many patients use more than one of these treatments over the course of the disease.
Outlook
How serious it is
Left untreated, CTEPH is a serious disease, and the strain on the right heart is progressive. That’s the hard part.
The hopeful part is that CTEPH stands almost alone among the pulmonary hypertension diagnoses in being curable, and modern results are good.
of patients are alive at three years with today’s combination of surgery, balloon procedures, and medication.
of people who have the surgery still have some residual pulmonary hypertension afterward, which is where balloon procedures and riociguat come in.
Among people who can’t have the curative surgery, the balloon and drug options have changed the outlook substantially.
That residual pressure is worth knowing about so you’re not caught off guard. And because the small-vessel disease I mentioned earlier can persist, follow-up at an expert center continues after treatment. CTEPH is manageable and often curable, and it’s also a condition you stay connected to your care team about for the long run.
The one thing I most want you to take away
Early referral to a center that specializes in CTEPH is the biggest factor in doing well. These centers have the surgeons, the interventional teams, and the imaging experience that a condition this uncommon requires, and the difference between an expert program and an occasional operator is real. If you’ve had a pulmonary embolism and you’re still breathless months later, or you have unexplained and worsening breathlessness with no clear cause, ask about CTEPH by name and about being referred to a specialized center. It’s a diagnosis that’s easy to miss and very much worth catching.
Common questions
Common patient questions
Is CTEPH the same as having another blood clot?
No. A new pulmonary embolism is a fresh clot that just arrived and can usually be dissolved by your body with the help of blood thinners. CTEPH is old clot that already turned into scar tissue built into the artery wall, which blood thinners can’t clear. That difference is exactly why CTEPH needs surgery or balloon procedures rather than more of the same medication.
I had a pulmonary embolism and recovered. Should I be worried about CTEPH?
Most people who have a pulmonary embolism never develop CTEPH. The one thing to watch for is breathlessness that lingers or gets worse in the months after your clot. If your exercise tolerance isn’t coming back the way you’d expect, or it’s sliding backward, tell your doctor and ask whether CTEPH should be ruled out. Catching it early is what makes the treatment work best.
Can CTEPH really be cured?
For the right candidate, yes. Pulmonary thromboendarterectomy, the operation that removes the old clot, can restore near-normal lung artery pressures and is potentially curative. Whether you’re a candidate depends on where the disease sits in the lung arteries, which is why you want the evaluation done at an expert center. When a full cure isn’t possible, balloon procedures and medication can still improve symptoms and survival a great deal.
Will I be on blood thinners forever?
Yes. Everyone with CTEPH stays on lifelong anticoagulation, whether or not they have surgery. The blood thinner won’t dissolve the organized scar tissue that’s already there, but it protects you against new clots forming on top of the existing disease, which would make things worse.
Why didn’t anyone catch this sooner?
CTEPH is hard to spot. It’s uncommon, its main symptom is gradual breathlessness that mimics ordinary things like aging and being out of shape, and up to a quarter of people who have it never had a diagnosed clot to raise suspicion. A delay isn’t a sign anyone was careless. It’s the nature of the disease. What helps most is knowing the pattern, so that persistent breathlessness after a clot, or unexplained and worsening breathlessness, gets the workup it deserves.
References
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Published on damianrasch.com. The above information was composed by Dr. Damian Rasch, drawing on individual insight and bolstered by digital research and writing assistance. The information is for educational purposes only and does not constitute medical advice.