Pulmonary Vascular Involvement in Chronic Obstructive Pulmonary Disease. Is There a Pulmonary Vascular Phenotype?

Although often clinically unrecognized, the pulmonary circulation is frequently affected in patients with chronic obstructive pulmonary disease (COPD), and the presence of pulmonary vascular disease is associated with poor prognosis and frequent exacerbations. In most cases the presenting pulmonary hypertension (PH) is relatively mild, but in a subset of COPD patients, the presence of certain clinical features supports the existence of a “pulmonary vascular phenotype”. Such a phenotype would be characterized by severe pre-capillary PH with strongly elevated pulmonary vascular resistance, moderate airflow limitation, severely decreased diffusion capacity for carbon monoxide, normo- or hypocapnia, circulatory exercise limitation and progressive right heart failure. Additional molecular and genetic features of this phenotype have been suggested. Although current PH guidelines do not suggest targeted therapy with pulmonary arterial hypertension drugs for COPD patients and prospective controlled studies are la...