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Knowledge is power – the key to ensuring faster PAH diagnoses

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Dr Luke Howard

PAH Specialist, London

Affecting just over 3,000 people in the UK, pulmonary arterial hypertension (PAH) is a rare and incurable disease that’s tough to spot. PAH symptoms are somewhat non-specific, so it can be misdiagnosed and mistreated as a result.

Rare diseases pose all sorts of problems for patients and clinicians. Those charged with recognising them often lack knowledge of the conditions. Those with the disease may face an agonising and often painful wait to get the answers they need. Dr Luke Howard, an expert in PAH, shares his views on how those in primary care can be better equipped to spot the condition.

Being diagnosed with a potentially life changing, and indeed life-threatening, disease is a daunting prospect for anyone. Should that disease be a particularly rare condition, such as pulmonary arterial hypertension (PAH), the likelihood is that many GPs or primary care professionals won’t have seen enough cases in their career to immediately recognise PAH. Diagnosis can be slow.

Tragically, a huge number of PAH patients are misdiagnosed at first, with asthma the most common diagnosis.

PAH is often mistaken for asthma

And that’s a big problem. As a rare, incurable and devastating disease, PAH affects the heart and lungs, causing both a narrowing of the blood vessels that connect the right side of the heart to the lungs and a thickening of the blood vessel walls, leaving patients struggling to breathe and carry out daily activities. This leads to the heart having to work far harder to pump blood through the lungs and oxygenate the blood.

PAH is characterised by breathlessness, extreme fatigue, fainting and chest pain, and is a disease that affects people of all ages, often developing in early adulthood, and predominantly affects females.

How many GPs, when presented with a breathless patient in their 20s or 30s, will suspect a serious heart or lung condition? This, according to Dr Luke Howard, a specialist in PAH, based in London, is part of the issue.

“Tragically, a huge number of PAH patients are misdiagnosed at first, with asthma the most common diagnosis. Clinically speaking, this is often not well thought through. ‘Breathlessness while exercising – must be asthma’.”

“If you look at the two – there’s a clear clinical difference. Asthma is typically episodic, with coughing and wheezing, often brought on by certain specific triggers such as hay fever or damp. With PAH, a patient will be constantly breathless. Whether they’re walking along the street or doing some light exercise.”

Speed of diagnosis and treatment is crucial for a PAH patient

As a clinician  who sees how valuable time can be in preventing the often severe episodes and hospitalisations that an untreated PAH patient might expect before their diagnosis, Dr Howard is passionate about the immediate need to better educate GPs on how to spot PAH – or at least more realistically realise they’re dealing with something more complex than asthma and refer on for more detailed assessment.

“Doctors must ask themselves: ‘Does it actually sound like asthma? Because if it doesn’t, it could be something more serious, such as PAH’,” he says.

But early diagnosis is often hindered by a lack of early symptoms. Often, patients are likely to have had the disease for years before they are diagnosed. Sometimes, diagnosis only occurs after a life-threatening, heart-related event. By this time, more often than not, the PAH has become quite developed.

“Part of the problem with PAH is that, because the lungs have so much reserve, quite a lot of changes can occur in the lung vessels before the heart starts to notice it’s working that much harder. The heart tends to be fine until the pulmonary hypertension is quite progressed,” says Dr Howard.

As a disease that can only be formally diagnosed by a catheterisation of the heart, which then measures pressure within the pulmonary artery – the blood vessel that connects the right side of the heart to the lungs – Dr Howard says that early diagnosis is often impossible.    

Ultrasound probes for heart distention might improve chances of earlier diagnosis

“Primary care doctors may see one or two patients with this condition in their entire career. So, we can’t expect them to think of PAH when they see it when they’ll see so many people with breathlessness in comparison.

But what they do need to do is say: ‘Well, if it’s not asthma, then I need to refer it on’.”

Dr Howard insists that things can be improved upon. Establishing rapid response units for breathlessness to mirror those for chest pain – or increasing access to echocardiography to further investigate heart distention and breathlessness – would both help. As it stands, treatment and support remain focussed within seven centres in the UK.

This feature has been organised and funded by Janssen UK and written on the company’s behalf by Mediaplanet, based on interviews with Dr Luke Howard, an expert in PAH, and Nina Meinzer, a PAH patient. The views expressed here are their own opinions.

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