The purpose of this study is to determine the timeline of progression from pre-pulmonary hypertension to diagnosable pulmonary hypertension based on right heart catheterization. Moreover, to determine the timeline for progression from diagnosable pulmonary hypertension to clinical worsening of disease as defined as death, hospitalization, or worsening of PHT symptoms.

Systemic sclerosis (SSc) is a rare, often fatal idiopathic disease, which has no effective therapy. One of the most major complications of systematic sclerosis is pulmonary hypertension (PHT), which is now the cause of all scleroderma related deaths. New therapeutic advances have improved short-term management of pulmonary hypertension in scleroderma, but long-term outcomes are unknown. With this in mind, Dr. Steen has developed Pulmonary Hypertension Assessment Registry of Scleroderma (PHAROS), a preventive, multi-center, web based observational study that looks at the natural history and outcome of scleroderma patients who are at high risk or have early pulmonary hypertension. Patients entered into the registry will be followed in prospective fashion noting the clinical course of disease by both scheduled and event driven follow up. A thorough baseline history will be collected to determine key prognostic and correlative factors for both disease prevalence and progression. Yearly follow up consisting of questionnaires, pulmonary function tests, echocardiogram, 6 minute walk tests and predefined patient characteristics will also be conducted to further understand and note the progression of scleroderma related PAH. Event driven follow up will occur to record findings and record specific predetermined events in the clinical course of disease.

1. Global Inclusion Criteria

   • Eligible patients must meet all of the following inclusion criteria:
   • Patient ≥ 18 years with a clinical diagnosis of SSc (ACR criteria or the LeRoy criteria for limited or diffuse scleroderma

2. Specific Inclusion Criteria

   • Diagnosis of "pre" pulmonary arterial hypertension defined as:
   • Echocardiogram with a resting sPAP of ≥ 40mmHg Or
   • Pulmonary function test with FVC >70% and a DLCO <55% of predicted or a FVC/DLco ratio >1.6. or
   • Right heart catheterization which shows or a mean PA pressure > 30mmHg with exercise (with a mPAP < 25mmHg at rest)

Patients entered as a 'pre'-pulmonary arterial hypertension who then undergo right heart catheterization and are found to have pulmonary arterial hypertension, pulmonary venous hypertension or diastolic dysfunction or pulmonary hypertension secondary to interstitial lung disease will be followed as a definite PH patient and classified into the appropriate category.

• Diagnosis of definite pulmonary hypertension Patients with pulmonary hypertension with a right heart catheterization showing a mean PA pressure > 25mmHg, diagnosed in the past 6 months.

Classification of PH Group 1 PAH - Patients with mPAP ≥ 25mmHg with a wedge < 15mmHg Group 2 PVH - Patients who have a mean PA pressure ≥ 25mmHg with a wedge pressure which is > 15 mmHg Group 3 PH-ILD Patients who have a mean PA pressure ≥ 25mmHg (on right heart catheterization) who have moderate to severe interstitial fibrosis on HRCT scan with a FVC and TLC < 65% predicted

b. Exclusion Criteria

• Diagnosis and treatment of pulmonary hypertension for > 6 months
• Patients with known severe interstitial fibrosis, pulmonary thrombotic disease, heart failure, cardiomyopathy,history of coronary artery disease or other cardio-pulmonary problems which could cause pulmonary hypertension are not eligible for the 'pre'-pulmonary hypertension but do qualify for the definite pulmonary hypertension group if they have a right heart catheterization showing a mean PAH >25mmHg.

Primary care, rheumatology and pulmonary hypertension clinics.