The 4th World Symposium on Pulmonary Hypertension was the ?rst international meeting to focus not only on pulmonary arterial hypertension (PAH)but also on the so-called non-PAH forms of pulmonary hypertension (PH).The term “non-PAH PH”summarizes those forms of PH that are found in groups 2to 5of the current classi?ca-tion of PH,that is,those forms associated with left heart disease,chronic lung disease,recurrent venous throm-boembolism,and other diseases.Many of these forms of PH are much more common than PAH,but all of them have been less well studied,especially in terms of medical therapy.The working group on non-PAH PH focused mainly on 4conditions:chronic obstructive lung disease,interstitial lung disease,chronic thromboembolic PH,and left heart disease.The medical literature regarding the role of PH in these diseases was reviewed,and rec-ommendations regarding diagnosis and treatment of PH in these conditions are provided.Given the lack of ro-bust clinical trials addressing PH in any of these conditions,it is important to conduct further studies to establish the role of medical therapy in non-PAH PH.(J Am Coll Cardiol 2009;54:S85–96)?2009by the American College of Cardiology Foundation

Previous international meetings on pulmonary hyperten-sion (PH)have focused predominantly on pulmonary arterial hypertension (PAH),a form of PH that is usually severe but overall quite rare.The 4th World Symposium was the ?rst to assign a working group to address in detail the so-called non-PAH forms of PH,that is,those forms of PH that are encountered in patients with chronic

obstructive pulmonary disease (COPD),interstitial lung disease (ILD),left heart disease (LHD),venous throm-boembolism,and other conditions.It is a paradox in the ?eld of PH that one of the less common forms,that is,PAH,has been extensively studied,whereas fewer data are available on other types of PH,many of which are far more common.At the same time,drugs with proven ef?cacy in PAH (1–3)are being increasingly used in other forms of PH,despite the virtual absence of clinical trials supporting this approach.

Pulmonary hypertension in chronic lung disease sub-sumes COPD,ILD,and other diffuse parenchymal lung diseases such as sarcoidosis,connective tissue disease,or pulmonary Langerhans cell histiocytosis.Space limitation prevents a discussion of the rarer diseases,such as sarcoid-osis and pulmonary Langerhans cell histiocytosis,which are often associated with clinically relevant PH (4).Epidemiology,Features,

and Importance of PH in COPD

The prevalence of PH in COPD depends on the population under study,the de?nitions applied,and the tools used to evaluate patients (5).Most hemodynamic studies have been

From the *Department of Respiratory Medicine,University of Hannover Medical School,Hannover,Germany;?Department of Respiratory Medicine,Hospital Clinic,CIBERES,University of Barcelona,Barcelona,Spain;?Division of Pulmonary and Critical Care Medicine,University of California,San Diego,La Jolla,California;§Department of Medicine,Pulmonary and Critical Care Medicine,Johns Hopkins University School of Medicine,Baltimore,Maryland;?Division of Cardiology,Medical University of Vienna,Vienna,Austria;?Institute of Cardiology,University of Bologna,Bologna,Italy;#Division of Pulmonary and Critical Care Medicine;University of Michigan Health System,Ann Arbor,Michigan;**Department of Pathophysiology,Free University of Brussels,Brussels,Belgium;??Department of Pulmonology,Medical University of Graz,Graz,Austria;??Pulmonary Vascular Disease Unit,Papworth Hospital,Cambridge,United Kingdom;§§Department of Cardiology,Mayo Clinic,Rochester,Minnesota;??Department of Allergy,Pulmonary and Critical Care Medicine;Vanderbilt University Medical Center,Nashville,Tennessee;??Pulmo-nary Department,Heart Institute,University of S?o Paulo Medical School,S?o Paulo,Brazil;##Department of Chest Medicine,Institute of Tuberculosis and Lung Diseases,Medical University of Warsaw,Warsaw,Poland;and the ***Department of Cardiovascular Medicine,Mayo Clinic,Rochester,Minnesota.Please see the end of this article for each author’s con?ict of interest information.

Manuscript received February 6,2009;accepted April 15,2009.

Journal of the American College of Cardiology

Vol.54,No.1,Suppl S,2009?2009by the American College of Cardiology Foundation ISSN 0735-1097/09/$36.00Published by Elsevier Inc.doi:10.1016/j.jacc.2009.04.008