Beyond the World Symposium on Pulmonary Hypertension: practical management of pulmonary arterial hypertension and evolving concepts

Abstract

Pulmonary hypertension (PH) is a common complication of most cardiac and respiratory disorders. It must not be confused with pulmonary arterial hypertension (PAH), a rare, incurable, and rapidly evolving condition. With a median survival of 2.8 years when untreated, PAH is without any doubt one of the most severe cardiovascular disorders. Despite its uncommon nature, it is remarkable that PAH has well-established guidelines for management and an evidence-based treatment algorithm. These peculiar achievements witness decades of discoveries, resulting not only from intense collaborative research but also from industry/academic partnership to develop new therapies. In fact, scientific rigour, creativity and partnership probably best define the ‘PH community’. First held in 1973, then every 5 years since 1998, the World Symposium on Pulmonary Hypertension (WSPH) is one of the key drivers of progress in PAH. Proceedings of the 6th WSPH provided the leading edge in PH, identified gaps in evidence and proposed important plans for the future. With this supplement, the authors aim to address some evolving paradigms and provide specific insights into the practical management of PAH, a year after the 6th WSPH. The haemodynamic definition of PH has recently been debated extensively, from which a proposal for a revised definition has emerged. It is now recognized that a mean pulmonary artery pressure (mPAP)>20mmHg and a pulmonary vascular resistance (PVR) 3 Wood units (WU) should be considered abnormal. This revised definition has several advantages as it takes into account the impact of an increased mPAP on prognosis, helps early identification of patients in groups at risk who warrant attention and may allow early interventions for specific forms of PH. This change in paradigm gives PVR a greater role in the characterization of pulmonary vascular disease (PVD), although more data are needed to establish how this truly reflects changes in the structure of the pulmonary vessels. In addition, this revised definition may allow a better management in patients with systemic sclerosis, carriers of genetic mutations associated with PAH and even chronic thromboembolic disease that may revisit the terminology of Group 4 PH in the future. The revised definition of PH will have an impact on screening strategies for PAH. Due to the rare nature of the disease, screening is defined as tests to aid early detection of PAH in asymptomatic patients belonging to groups at risk of developing PAH. In fact, significant PVD may be present even in the absence of symptoms. A structured screening programme positively impacts patient management by favouring early intervention. The current approach mostly relies on echocardiography and multidimensional assessment or scores. However, there is a growing interest in the use of blood-based biomarkers, exhaled volatile organic compounds, and new imaging techniques. In addition, artificial intelligence and analysis of patients’ healthcare utilization behaviour hold great promise. With the availability of specific therapies and better disease awareness, new issues are emerging in the management of PAH. Two of the most challenging issues are associated with the increased burden of comorbidities and the care of elderly patients. Both represent diagnostic challenges and potential difficulties in therapy maintenance. Cardiac and respiratory comorbidities are increasingly recognized in patients with PAH, both being confounding factors to establish a precise diagnosis: three quarter of patients over 65years of age suffer from at least one coexisting condition that may negatively impact *Corresponding author. Tel: þ32 25554866, Fax: þ32 2 555 4339, Email: [email protected]