Vessels and pressures: Update on the management of pulmonary arterial hypertension

Pulmonary hypertension (PH) refers to an abnormal elevation in pulmonary arterial pressure (PAP) under resting conditions. PH is often encountered in patients with chronic heart and lung disease. Rarely, it occurs in the absence of any identifiable heart or lung abnormalities. Under these conditions, the increase in PAP may be caused by diffuse remodeling of the distal pulmonary circulation characterized by an obliterative vasculopathy that leads to a marked increase in pulmonary vascular resistance, progressive right heart failure, and usually death. This disease is referred to as pulmonary arterial hypertension (PAH) and has become the focus of intense basic science and clinical research over the past quarter century. Since 1995, five classes of drugs that encompass more than a dozen specific agents have been developed and approved for the treatment of PAH. The large number of drugs and the myriad forms of pulmonary vascular disease has made the evaluation and treatment of PH an intriguing challenge. This review discusses the most recent definitions of PH and current classification of the pulmonary hypertensive diseases. An overview of the importance and proper approach to diagnosis is provided as well as the impact of patient selection on the approach to management. An evidence-based approach is used to determine how initial therapy is chosen and how additional medications can be used in patients who do not achieve treatment goals. Finally, the results of recently completed clinical trials that evaluated the safety and efficacy of a new class of medications that have been developed to target the underlying pathophysiology of PAH are presented and the potential impact on the management of PAH is discussed. The purpose of this review is to present the reader with an update on the current approach to evaluation and management of PH with an emphasis on PAH.