Diagnosis of PAH
Diagnosis of PAH
How is pulmonary arterial hypertension (PAH) diagnosed?
The early symptoms of pulmonary arterial hypertension (PAH), such as dyspnea, dizziness and fatigue, are often mild and are common to many other conditions.[1] As a result, PAH is a challenging disease to identify and the diagnosis cannot be made on symptoms alone.[1][2] Watch the video to understand why it sometimes takes more than 2 years to diagnose PAH.
The non-specific nature of the symptoms, coupled with the rarity of the disease, means that many patients are not diagnosed until the disease is already quite severe.[1]
Early diagnosis and therapeutic intervention can offer an improved outlook for patients.[3] That is why it is so critical to identify patients at risk of PAH and refer them to a specialist centre at the earliest opportunity to confirm the diagnosis.
Diagnosis of PAH
PAH should be considered in the differential diagnosis of exertional dyspnoea, syncope, angina and/or progressive limitation of exercise capacity, particularly in patients without apparent risk factors, symptoms or signs of common cardiovascular and respiratory disorders. Special awareness should be directed towards patients with associated conditions and/or risk factors for the development of PAH:[2]
- Family history
- Connective tissue disease
- Congenital heart disease
- Human immunodeficiency virus (HIV) infection
- Portal hypertension
- A history of drug or toxin intake known to induce PAH
When PAH is suspected, clinical history, symptoms, signs, electrocardiogram (ECG), chest radiograph, echocardiogram, PFTs, CT of the chest and a V/Q scan are all required in order to exclude diagnosis of left heart disease, lung disease or chronic thromboembolic pulmonary hypertension (CTEPH). To confirm diagnosis of PAH, referral to a PH specialist centre for RHC is required. A diagnostic-based algorithm can be found in the 2015 ESC/ERS clinical guidelines for the diagnosis and treatment of PH.[2]
Adapted from Galiè et al. 2016[2]
CT, computed tomography;
CTEPH, chronic thromboembolic pulmonary hypertension; DLCO, diffusing
capacity for carbon monoxide; ECG, electrocardiogram; ERS, European
Respiratory Society; ESC, European Society of Cardiology; HRCT,
high-resolution computed tomography; mPAP, mean pulmonary arterial
pressure; PAH, pulmonary arterial hypertension; PAWP, pulmonary artery
wedge pressure; PFT, pulmonary function test; PH, pulmonary
hypertension; PVR, pulmonary vascular resistance; RHC, right heart
catheterisation; RV, right ventricle; V/Q, ventilation-perfusion
Screening for PAH
The implementation of screening programmes targeting high-risk patient groups can help to identify patients earlier. The 2015 European Society of Cardiology and European Respiratory Society (ESC/ERS) guidelines recommend annual echocardiographic screening in asymptomatic systemic sclerosis (SSc) patients.[2]
Screening for PAH in patients with SSc has shown to result in an increase of 47% in survival after 8 years vs those detected during routine clinical practice.[4]
Adapted from Humbert et al. 2011[4]
CI, confidence interval; HR, hazard ratio; PAH, pulmonary arterial hypertension; SSc, systemic sclerosis
Screening
2015 ESC/ERS guidelines
Annual screening with echocardiography, PFTs and biomarkers may be considered in patients with systemic sclerosis.[2]
Echocardiography should always be performed when pulmonary hypertension (PH) is suspected, and may be used to infer a diagnosis of PH in patients in whom multiple different echocardiographic measurements are consistent with this diagnosis.[2] A transthoracic echocardiogram (TTE) is a non-invasive screening test for PH that may provide an estimate of the right ventricular systolic pressure, which is equivalent to the systolic pulmonary arterial pressure and the systolic right ventricular pressure.[5] In the initial investigation of patients with PAH it is important to obtain adequate images of the right heart.[2] Tricuspid regurgitation velocity and the presence of other echocardiographic signs should be combined to estimate the probability of PH.[2]
Instructional videos
Watch how Prof. Dr. Johan De Sutter (cardiologist, AZ Maria Middelares Ghent) and Dr. Michiel Dumolein (cardiologist, AZ Groeninge) explain which echocardiographical parameters are of importance to PH and how these can be measured and interpreted.
Via 10 highly interesting videos, they will tell you everything there is to know about screening for PH via echo.
Right ventricle/left ventricle basal diameter ratio >1,0
Flattening of the interventricular septum
Tricuspid Annular Plane Systolic Excursion (TAPSE) [6]
Peak systolic velocity of tricuspid annulus (s’) [7]
Peak tricuspid regurgitation velocity (m/s)
Right ventricular outflow Doppler
acceleration time < 105 msec
Early diastolic pulmonary regurgitation velocity > 2,2 m/sec
PA diameter > 25 mm
Inferior cava diameter > 21 mm
with decreased inspiratory collapse
Right atrial area (end-systole) > 18 cm²
Right heart catheterisation (RHC) is required for the definitive diagnosis of PAH.[2] RHC involves directing a pulmonary artery catheter into the right side of the heart to assess the cardiopulmonary haemodynamics. The procedure is technically demanding so it is recommended that RHC is only undertaken at specialist pulmonary hypertension (PH) centres.[2]
Confirmation of PH[2]
- mPAP ≥25 mmHg (according to current guidelines)
Confirmation of PAH[2]
- mPAP ≥25 mmHg
- Normal PAWP (≤15 mmHg)
- PVR >3 Wood units
- Excluding other causes of pre-capillary PH
Adapted from Pagnamenta et al. 2017[6]
mPAP, mean pulmonary
arterial pressure; PAP, pulmonary arterial pressure; PAWP, pulmonary
artery wedge pressure; PVR, pulmonary vascular resistance; RAP, right
arterial pressure; RHC, right heart catheterisation; RVP, right
ventricular pressure
Upon diagnosis, patients are assessed for risk of disease progression. Guidelines recommend regular multiparameter risk assessment, both at diagnosis and follow-up (every 3–6 months) to allow the treatment strategy to be tailored to the individual patient at the earliest opportunity. The risk status of patients can be categorised as either low, intermediate or high. This corresponds to an estimated 1-year mortality of <5%, 5–10% or >10% respectively and is based on a number of determinants including WHO functional class, exercise capacity and haemodynamic parameters. There is no single variable that can provide sufficient prognostic information on its own; a multidimensional approach is required. [2]
Adapted from Galiè et al. 2016[2]
BNP, brain natriuretic
peptide; CI, cardiac index; CMR, cardiovascular magnetic resonance;
NT-proBNP, N-terminal pro-B-type natriuretic peptide; PH, pulmonary
hypertension; RA, right atrium; RAP, right atrial pressure; 6MWD,
6-minute walk distance; SvO2, mixed venous oxygen saturation; VE/VCO2, ventilatory equivalents for carbon dioxide; VO2, oxygen consumption; WHO, World Health Organization
A patient’s diagnosis story
PAH patients often receive their diagnosis very late, which is detrimental to their outcomes.[8] Sometimes, it can take more than 2 years for them to get clarity on their symptoms, while the median survival without treatment is estimated at around 2,8 years.[9][10]
PAH patient Murielle was so kind to share her diagnosis story with us.
Watch and find out:
- How long it took before her PAH was diagnosed correctly,
- In which ways the long wait impacted her emotionally,
- How Murielle still lives live to the full despite her illness,
- … and so much more.
Read Murielle's full story also in the handy case report! Now including the latest ESC/ERS Guidelines on the diagnosis of pulmonary (arterial) hypertension.
PH Centers
An overview of all PH centers in Belgium and Luxemburg, with contact details of the treating physicians.
Get in touch with our team
Meet our Product Specialists and Medical Science Liaisons, who are more than happy to discuss PAH diagnostics and other subjects with you.
Pathophysiology of PAH
While the exact cause of PAH is uncertain, a clearer picture of the underlying pathological mechanisms is emerging.
Treatment of PAH
Modern treatments can significantly improve patients’ symptoms and slow the rate of clinical deterioration.