Suspected pulmonary hypertension and CTEPH

ESC/ERS 2022 pulmonary hypertension; ACR AC Suspected Pulmonary Hypertension (2022)

Echocardiography is the screening test that raises or lowers the probability; once it has raised it, imaging exists to answer one question first: is this chronic thromboembolic disease, the form that is potentially curable by surgery. Perfusion scintigraphy answers that better than CT, which is why it comes first here and nowhere else in the chest.

Unexplained exertional breathlessness with echocardiographic signs of raised pulmonary pressures or right ventricular strain, or persisting breathlessness months after an acute pulmonary embolism.

Referenced decision support — confirm against your local protocol.

Decision support, not a directive. Protocols and timings shown are typical published ones — your local protocol takes precedence, and the vetting radiologist decides.

The request in front of you

Everything is optional. Leave a field alone and the answer assumes nothing — the verdict updates as you go.

Study requested

What the referrer actually asked for. It is evidence of intent, not a constraint on the right answer.

Contrast as written

What the request form says, not what it should say.

Age

Pick a band, or type an exact age if it matters.

years

Pregnancy status

Renal risk factors

The question a vetter can actually answer from the request. An explicit “none known” is a real answer, and it removes checks rather than deferring them.

Previous contrast reaction

The pathway — tap anything already done

Marking a study complete moves the answer on. A patient arrives partway through a pathway far more often than at the start of one.

Accept as requested

Transthoracic echocardiography — standard adult study

Transthoracic echocardiography

What we'd amend, and why

Nothing further should be requested in suspected pulmonary hypertension until an echocardiogram has been done, and where it has not been, it is the study this card should return. The peak tricuspid regurgitant velocity, combined with right ventricular and right atrial size, septal shape, pulmonary artery diameter and inferior vena caval collapse, is what assigns the low, intermediate or high echocardiographic probability that the whole ESC/ERS algorithm is built on — and it does it with no radiation and no contrast. It also finds the large group whose breathlessness is left-sided: valve disease and left ventricular systolic or diastolic failure are commoner causes of a raised pulmonary pressure than any of the pulmonary vascular diseases, and finding one of them ends the pathway rather than advancing it. Two limits belong on the request. Absent or trivial tricuspid regurgitation means no pressure can be estimated at all, which is not the same as a normal pressure; and the estimate is derived rather than measured, so it can never make the diagnosis, which remains a right heart catheter measurement.

Nothing needs resolving before this goes ahead. Routine checks below are owned downstream.

How was this decided?

pathwayadult — Adults

Decision support only. Local protocol takes precedence.

Pathways

Big forks are separate pathways; the first whose conditions match is the one used.

Adults

Matches your inputsDefault

Role	Study & protocol	Why this answers the question
First line	Transthoracic echocardiography Transthoracic echocardiography — standard adult study usually appropriate	Nothing further should be requested in suspected pulmonary hypertension until an echocardiogram has been done, and where it has not been, it is the study this card should return. The peak tricuspid regurgitant velocity, combined with right ventricular and right atrial size, septal shape, pulmonary artery diameter and inferior vena caval collapse, is what assigns the low, intermediate or high echocardiographic probability that the whole ESC/ERS algorithm is built on — and it does it with no radiation and no contrast. It also finds the large group whose breathlessness is left-sided: valve disease and left ventricular systolic or diastolic failure are commoner causes of a raised pulmonary pressure than any of the pulmonary vascular diseases, and finding one of them ends the pathway rather than advancing it. Two limits belong on the request. Absent or trivial tricuspid regurgitation means no pressure can be estimated at all, which is not the same as a normal pressure; and the estimate is derived rather than measured, so it can never make the diagnosis, which remains a right heart catheter measurement.
First line	Ventilation/perfusion scintigraphy V/Q or perfusion-only scintigraphy usually appropriate	Chronic thromboembolic material organises, retracts and becomes incorporated into the vessel wall as webs and bands, so it stops behaving like a filling defect and often disappears on CT — but the territory it supplies stays underperfused. Scintigraphy measures perfusion directly rather than inferring it from luminal anatomy, which is why a normal perfusion scan effectively excludes chronic thromboembolic pulmonary hypertension while a normal CT pulmonary angiogram does not. Getting this order right matters more than usual, because CTEPH is the one form of pulmonary hypertension that surgery can cure.
Second line	CT Pulmonary Angiogram (CTPA) CTPA — Standard Bolus-Tracked	Once perfusion imaging says chronic thromboembolic disease is present, CT defines whether it is surgically accessible: proximal webs, bands, pouch defects and abrupt calibre change in the main and lobar arteries are operable, distal disease is not. The same acquisition shows the parenchymal and airway disease, the left heart, and the mosaic attenuation that indicates the perfusion mismatch, and it measures the pulmonary artery calibre and right heart chamber sizes that support the diagnosis.
Problem solving	Cardiac MRI Cardiac MRI — function and late gadolinium enhancement	The right ventricle determines prognosis in pulmonary hypertension, and it is the chamber echocardiography measures least reliably because of its shape and its position behind the sternum. Cardiac MRI gives reproducible right ventricular volumes, mass and ejection fraction from a short-axis cine stack without geometric assumptions, which is what makes it the reference for serial assessment and for detecting associated congenital shunts.

Pitfalls

Accepting a CT pulmonary angiogram as sufficient to exclude chronic thromboembolic disease. Organised chronic clot is frequently invisible on CT to an eye looking for acute filling defects, and the consequence is a missed operable diagnosis.
Scanning during or immediately after an acute embolus and calling the result chronic. The diagnosis requires persistence beyond about three months of anticoagulation.
Attributing a mismatched perfusion defect to CTEPH without considering the other causes — pulmonary artery sarcoma, fibrosing mediastinitis, large vessel vasculitis and extrinsic compression all reproduce the pattern.
Requesting a ventilation study routinely when a perfusion-only acquisition with a recent chest radiograph answers the question at lower dose.
Reporting a dilated pulmonary artery as diagnostic. Calibre correlates only loosely with pressure and cannot make or exclude the diagnosis on its own.
Entering the pathway without an echocardiogram. Perfusion imaging asks whether the pulmonary hypertension is thromboembolic; it presupposes that something has already said there is pulmonary hypertension, and it will not find the left heart disease that explains most raised pressures.
Reading an echocardiogram with no measurable tricuspid regurgitant jet as excluding pulmonary hypertension. The pressure was not estimated, not estimated as normal.

Priors — what to pull first

Retrieve the CT from the original pulmonary embolism if there was one. Residual clot at three to six months, and the presence of mosaic attenuation or bronchial artery hypertrophy on that study, are what distinguish resolving acute disease from established chronic disease.
Look for previous perfusion imaging — a mismatched defect that was present before the acute episode changes the interpretation entirely.

What makes a good request

Echocardiography is the entry point and is a legitimate request on this card in its own right: where it has not been done, it is the study to do first, and both it and perfusion scintigraphy are correct answers depending on where the patient has got to. Say on the request whether an echo has been performed and what it showed, because that single fact decides which of the two the patient needs.
A good request states the echocardiographic estimate and the right heart findings, the natriuretic peptide, the history of any previous venous thromboembolism and how long anticoagulation has run, and the lung function.
Symptomatic mismatched perfusion defects persisting beyond about three months of anticoagulation after acute pulmonary embolism are the trigger for referral to a specialist centre — that time interval is why a scan done during the acute episode does not answer this question.

Scoring this once it is done

The classification and risk tools this question ends in.

RV/LV Diameter Ratio on CTPA Wells Score for Pulmonary Embolism PERC Rule (Pulmonary Embolism Rule-out Criteria)Revised Geneva Score for Pulmonary Embolism Age-Adjusted D-dimer (ADJUST-PE)PESI / sPESI (Pulmonary Embolism Severity Index)Qanadli CT Pulmonary Obstruction Index

How these studies are acquired

Contrast, phases and timing for every study on the pathways above.

Transthoracic echocardiography — standard adult study V/Q or perfusion-only scintigraphy CTPA — Standard Bolus-Tracked Cardiac MRI — function and late gadolinium enhancement

Confirm locally

Transthoracic echocardiography — standard adult study: timings are typical — confirm against local protocol.
Timings, contrast volumes and rates above are typical published values. Your department's protocol, scanner and patient population decide the actual numbers.
Safety thresholds and premedication policy follow local policy where it differs from the cited guidance.

References

Implemented from the cited published sources. Educational and workflow support only; confirm against current guidelines and local policy before clinical use.