Idiopathic pulmonary arterial hypertension

A rare, frequently fatal disease, most commonly seen in women, that is best managed in centres with expertise in pulmonary hypertension.

Presenting symptoms and signs are non-specific and include dyspnoea on exertion, fatigue, and a loud pulmonary component of the second heart sound.

Diagnosis of exclusion. Transthoracic Doppler echocardiography and right heart catheterisation can diagnose pulmonary hypertension. Laboratory tests and imaging studies can rule out known causes of pulmonary hypertension.

General supportive therapy includes oral anticoagulants, diuretics, supplemental oxygen, and digoxin.

Targeted treatment options include parenteral, inhaled, and oral prostanoids, oral endothelin receptor antagonists, oral phosphodiesterase type-5 inhibitors, the soluble guanylate cyclase stimulator riociguat, and the selective prostacyclin IP receptor agonist selexipag.

Prognosis is not good, as most patients eventually develop right ventricular failure.

Idiopathic pulmonary arterial hypertension (IPAH) is a disease of the small pulmonary arteries characterised by vascular proliferation and remodelling. It results in a progressive increase in pulmonary vascular resistance (PVR) and, ultimately, right ventricular failure and death.[1]Humbert M, Sitbon O, Simmonnau G. Treatment of pulmonary arterial hypertension. N Engl J Med. 2004 Sep 30;351(14):1425-36. http://www.ncbi.nlm.nih.gov/pubmed/15459304?tool=bestpractice.com It is defined by a mean pulmonary arterial pressure ≥25 mmHg at rest with pulmonary capillary wedge pressure ≤15 mmHg and PVR >3 Woods units, without a known cause.[2]Badesch DB, Champion HC, Sanchez MA, et al. Diagnosis and assessment of pulmonary arterial hypertension. J Am Coll Cardiol. 2009 Jun 30;54(1 Suppl):S55-66. http://www.onlinejacc.org/content/54/1_Supplement/S55 http://www.ncbi.nlm.nih.gov/pubmed/19555859?tool=bestpractice.com