PHCentral March 24, 2011[email protected] Join the Registry Learn more about: Pulmonary Arterial Hypertension Related Access Program Pfizer – Pulmonary Arterial Hypertension (PAH) Pfizer – Pulmonary Arterial Hypertension Bayer – Pulmonary arterial hypertension Pulmonary Hypertension Information, Support and Advocacy Since 1999.