Pulmonary Hypertension

Overview

Pulmonary hypertension (PH) is an increase in mean pulmonary arterial pressure (PAP), which can be caused by, or associated with a wide variety of conditions.

Idiopathic pulmonary arterial hypertension (IPAH) is a rare disorder that can be defined as a sustained elevation in PAP and pulmonary vascular resistance, with normal pulmonary artery wedge pressure, in the absence of a known cause. It is a diagnosis of exclusion after other possible causes of PH have been excluded. It is a severe and often rapidly progressive illness in many cases. (1)

Secondary pulmonary hypertension is more common than IPAH and is seen in severe respiratory and cardiac disease, occurring in 18-50% of patients assessed for transplantation or lung volume reduction surgery, and in 7-83% of those with diastolic heart failure.

Between 0.5% and 4% of patients develop chronic thromboembolic PH after acute pulmonary embolism. There is an increased risk for patients presenting with large, recurrent or unprovoked clots.

Classification

The World Health Organization (WHO) has devised a classification system (2).

• Group 1 - – Pulmonary arterial hypertension including idiopathic, heritable forms and in association with connective tissue disease, portal hypertension and congenital heart disease.
• Group 2 - secondary to left heart and valvular heart disease.
• Group 3 - secondary to chronic lung disease and environmental hypoxaemia.
• Group 4 - due to chronic thromboembolic disease.
• Group 5 - metabolic disorders, systemic disorders, haematological diseases, and other miscellaneous causes.

Who to Refer

Patients are usually diagnosed in secondary care following referral or investigation of symptoms.

Symptoms (often non-specific and diagnosis can be delayed as a consequence)

• Progressive dyspnoea on exertion

• Fatigue, weakness

• Chest discomfort

• Syncope or presyncope

• Peripheral oedema

• Haemoptysis

Signs

• Right ventricular (parasternal) heave

• Abnormal heart sounds - loud pulmonary second heart sound, murmur of pulmonary regurgitation, systolic murmur of tricuspid regurgitation

• Jugular venous distension

• Hepatomegaly

• Ascites

• Peripheral oedema

These symptoms and signs may overlap with left heart failure and lung disease—consider PH in patients with unexplained dyspnoea and normal left heart findings.

There may also be signs of associated conditions, such as connective tissue disease or liver disease.

Red Flags

Patients who are severely unwell or have acute symptoms may need to be admitted

Rapid Access clinics may be appropriate if admission is not required such as:

• Respiratory HOT Clinic - if breathless and threatening admission.
• Heart Failure clinic (urgent)

What to do before referral

If PH is suspected then consider the following investigations in primary care:

• Bloods - NTPro-BNP, UE, LFTs (portal hypertension), TFTs, and autoimmune screening (particularly antinuclear antibody to detect possible SLE/scleroderma-like syndrome).
• CXR to exclude other lung diseases although CXR is not useful for diagnosing PH.
• ECG - can show right ventricular hypertrophy and strain patterns but may be normal.
• Echocardiography to assess right ventricular function and estimate pulmonary arterial pressures.
• Pulmonary function tests.

Referral

From primary care there is no specific directly accessible Pulmonary Hypertension Clinic available via eRS in BNSSG.

Patients should be referred to the appropriate specialty (e.g. respiratory, cardiology, haematology, paediatrics (if <16years)) depending on symptoms and/or suspected cause.

Consider urgent referral to appropriate specialty if:

• Unexplained dyspnoea with raised NT-proBNP (see Heart Failure page)

• Echo showing high echocardiographic probability of pulmonary hypertension particularly in the absence of a clear secondary cause for PH

• Syncope with signs of right ventricular dysfunction

• Known connective tissue disease with suspected PH

Advice and guidance services may also be helpful if there is uncertainty about the most appropriate referral route.

There is a tertiary pulmonary hypertension service which accepts referrals for patients (adults and children) from other secondary care specialists across the South West region and Wales but does not accept referrals directly from GPs.

Post diagnosis management

Chronic Management (post diagnosis) in primary care: 

Targeted PAH therapies are prescribed and handled by the National Pulmonary Hypertension Centres. University Hospital Bristol works closely with the team at the Hammersmith Hospital, Imperial College Healthcare NHS Trust.

• • Vaccinations: Influenza, pneumococcal, COVID
  • Contraception advice: Pregnancy is high risk in patients with PAH and contraception (usually with progesterone based contraceptives) is advised
  • Blood tests (phlebotomy services) - to monitor liver function, blood counts and NTProBNP for patients on targeted PH therapies.
  • Supportive care: Psychological support, palliative involvement if advanced
  • Multidisciplinary care: Coordination with specialist PH centres

Prognosis

There have been significant improvements in survival and quality of life in patients with PAH on therapies.

Idiopathic PAH patients who are untreated are known to have a median survival of 2-3 years (1).

Discussions regarding end of life care and ReSPECT forms should be considered when appropriate.

Resources

(1) Pulmonary Hypertension. About Pulmonary Hypertension | Patient

(2) Secondary Pulmonary Hypertension - StatPearls - NCBI Bookshelf (nih.gov)

This page has been written with the kind support of Radwa Bedair, Consultant Cardiologist, UHBW.

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