Diagnosis and management of pulmonary hypertension related to chronic respiratory disease

Abstract

Pulmonary hypertension (PH) is a recognised and significant complication of chronic lung disease (CLD) and hypoxia (referred to as group 3 PH) that is associated with increased morbidity, decreased quality of life and worse survival. The prevalence and severity of group 3 PH varies within the current literature, with the majority of CLD-PH patients tending to have non-severe disease. The aetiology of this condition is multifactorial and complex, while the prevailing pathogenetic mechanisms include hypoxic vasoconstriction, parenchymal lung (and vascular bed) destruction, vascular remodelling and inflammation. Comorbidities such as left heart dysfunction and thromboembolic disease can further confound the clinical picture. Noninvasive assessment is initially undertaken in suspected cases (e.g.cardiac biomarkers, lung function, echocardiogram), while haemodynamic evaluation with right heart catheterisation remains the diagnostic gold standard. For patients with suspected severe PH, those with a pulmonary vascular phenotype or when there is uncertainty regarding further management, referral to specialist PH centres for further investigation and definitive management is mandated. No disease-specific therapy is currently available for group 3 PH and the focus of management remains optimisation of the underlying lung therapy, along with treating hypoventilation syndromes as indicated.

Pulmonary hypertension in chronic obstructive pulmonary disease: current understanding, knowledge gaps and future directions

“…It is important to note that most studies have failed to consistently show a relationship between the severity of COPD (i.e., GOLD stage or FEV1) and the severity of PH although most cite increasing incidence of PH as COPD progresses. This discrepancy, and the identification of severe PH in WHO group 3 patients with relatively preserved pulmonary function, was highlighted in recent articles where the term 'pulmonary vascular phenotype' in WHO group 3 PH was described [7][8][9][10]. Thus, there remain considerable uncertainties with regards to the risk factors for development of PH-COPD requiring the clinician to keep a high index of suspicion in the COPD patient with worsening dyspnea.…”

Pulmonary vascular disease for the general respiratory clinician

“…For example, phosphodiesterase inhibitors such as sildenafil are important agents in the management of PAH, but in group 3 PH any improvement they deliver in pulmonary haemodynamics is often offset by a worsening in gas exchange and functional status [ 4 ]. K rompa and M arino [ 5 ] discuss the identification and management of PH in chronic respiratory disease, including how current evidence suggests that care of these patients should be focussed on optimising management of the underlying respiratory disease, including use of oxygen therapy, noninvasive ventilation and pulmonary rehabilitation where appropriate. Meanwhile, recent data regarding the use of treprostinil in ILD patients with PH shows that ongoing trials of therapies specifically targeting the pulmonary vasculature remain worthwhile in patients with group 3 PH.…”