PAH diagnosis and referral: What’s new in 2022 ESC/ERS guidelines?

Pulmonary arterial hypertension (PAH) (WHO Group 1 pulmonary hypertension [PH]) is a rare, progressive and life-limiting disorder. Due to its nonspecific symptoms, early diagnosis of PAH is challenging, with 44 percent of patients being seen by ≥4 doctors before receiving a correct diagnosis. Aiming at earlier detection in the community, the European Society of Cardiology and the European Respiratory Society (ESC/ERS) 2022 guidelines provide a new diagnostic algorithm for PH and recommend fast-track referral at any time for patients with suspected PAH.

“The cardinal symptom of PH is dyspnoea on progressively minor exertion,” noted the authors of the ESC/ERS 2022 PH guidelines. Other common symptoms are related to the stages and severity of PH, including fatigue and rapid exhaustion, dyspnoea when bending forward, palpitations, haemoptysis, exercise-induced abdominal distension and nausea, weight gain due to fluid retention, and syncope during or shortly after physical exertion. [Eur Heart J 2022;43:3618-3731]

For patients with unexplained dyspnoea or symptoms/signs raising a suspicion of PH, the diagnostic algorithm has been simplified based on a three-step approach, including suspicion, detection and confirmation.

Patients with PH, including those with PAH, are likely seen by general practitioners for nonspecific symptoms. Initial evaluation should include a comprehensive medical (including familial) history, physical examination (including measurement of blood pressure, pulse oximetry and heart rate), oxygen saturation, natriuretic peptide test, and resting electrocardiogram (ECG). (Figure) “This first step may raise a suspicion of a cardiac or respiratory disorder causing the symptoms,” noted the authors.

“The second step of detection includes classical, noninvasive lung and cardiac testing. Among those tests, echocardiography is an important step in the diagnostic algorithm,” mentioned the authors. (Figure) Signs of PH include increased systolic pulmonary arterial pressure (sPAP) and enlarged right atrium/right ventricle (RA/RV).

Patients should be referred to a PH centre for further evaluation in two situations: 1) when an intermediate/high probability of PH is established; 2) when risk factors for PAH (ie, connective tissue disease, portal hypertension, HIV infection, and family history of PAH) or chronic thromboembolic pulmonary hypertension (CTEPH) is/are present. (Figure)

“Fast-track referral to a PH centre should be made when PAH or CTEPH is suspected,” highlighted the authors. “At any time, warning signs [ie, rapidly evolving or severe symptoms (WHO functional class III/IV), severely reduced exercise capacity, pre-syncope or syncope on mild exertion, clinical signs of RV failure] must be recognized as they are associated with worse outcomes and warrant immediate referral and management in PH centres.” (Figure)

The final step is confirmation. Right heart catheterization is the gold standard for diagnosing and classifying PH, and should be performed in a PH centre. Based on the revised haemodynamic definition, PAH may be diagnosed in patients with mean PAP >20 mm Hg and pulmonary vascular resistance >2 WU.

“This diagnostic process emphasizes the importance of sufficient awareness and collaboration between first-line, specialized medical and PH centres. Effective and rapid collaboration between each partner permits earlier diagnosis and management, and improves outcomes,” noted the authors.