Exercise Induced Pulmonary Hypertension in Systemic Sclerosis and Treatment With Ambrisentan

Phase 4

Completed

Conditions: Systemic Sclerosis
Shortness of Breath
Pulmonary Hypertension

Interventions: Drug: Ambrisentan

Registration Number: NCT01051960

Lead Sponsor: University of California, Los Angeles

Brief Summary: The purpose of this study is to determine the clinical characteristics and hemodynamic profiles that predict exercise induced pulmonary hypertension in 15 patients with systemic sclerosis. The study also aims to determine the effectiveness of Ambrisentan for subjects with exercise induced Pulmonary Arterial Hypertension (PAH) with scleroderma

Detailed Description: The current literature addresses therapies for patients with resting PAH only, diagnosed by right heart catheterization. However, the World Health Organization (WHO) also recognizes and defines exercise induced pulmonary arterial hypertension (ex-PAH), which may precede the development of resting PAH. The natural progression of PAH, especially during exercise, has not been well delineated. An exercise hemodynamic study previously showed that in normal healthy subjects the mean pulmonary pressure does not exceed 30mmHg even at maximal cardiac outputs. A prior study evaluated exercise Doppler echocardiography systemic sclerosis patients with normal resting echocardiograms, finding an abnormal response which was defined as an estimated right ventricular systolic pressure greater than 40 mmHg. In the same study, 6.6% of the patients progressed to resting PAH over the followup period of 12 months. Limited data is available regarding the prevalence of ex-PAH in systemic sclerosis using right heart catheterization.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 12

Inclusion Criteria

Systemic Sclerosis diagnosed by the American College of Rheumatology consensus statement including any of the following:
- Limited
- Diffuse
- Sine Scleroderma
Patients must be willing and able to undergo right heart catheterization with lower extremity cycle ergometry
Mean pulmonary artery pressure (mPAP) > 30mmHg with exercise; PCWP ≤ 15mmHg on RHC at rest
Men and women, ages 18 years of age or older
Standard adjunctive medications will be allowed concurrently in this study at the discretion of the treating pulmonologist and rheumatologist, including digoxin, diuretics, anticoagulants (e.g. warfarin), stable immunosuppression or other anti-fibrotic therapy for at least one month prior to enrollment

Exclusion Criteria

Resting PAH (mPAP > 25mmHg) on right heart catheterization
Other known causes of PAH including prior venous thromboembolism, HIV infection, chronic liver disease with portal hypertension, left ventricular systolic dysfunction (e.g. LVEF < 40%), and congenital causes of PAH
Severe hepatic disease precluding the use of ambrisentan (AST/ALT ≥3x ULN).
Women who are pregnant or breastfeeding.
Concurrent therapy with a prostanoid or prostanoid analogue, PDE5 inhibitors, or enrolled in another active clinical study.
Use of any prostacyclin or endothelial receptor antagonist (ERA) within 30 days before study entry.
Bed or wheel chair bound or a baseline 6-Minute Walk distance (6MWD) less than 150 meters.
Childbearing capable women who are unwilling or unable to use an acceptable method to avoid pregnancy for the entire study period.
New York Heart Association (NYHA) Classification: Class IV
Renal dysfunction (serum creatinine >2.5mg/dL).
Uncontrolled sleep apnea.

Study & Design

Study Type: INTERVENTIONAL

Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
ambrisentan	Ambrisentan	ambrisentan dosed at either 5mg or 10mg orally once per day

Primary Outcome Measures

Name	Time	Method
Change in Exercise Pulmonary Hemodynamics From Baseline to Week 24	24 weeks	We defined ePH (exercise PH) as an mPAP of 30 mmHg, PCWP of 18 mm Hg, and a transpulmonary gradient (TPG) of 15 mm Hg, where TPG equals mPAP minus PCWP. We defined ePVH (exercise pulmonary venous hypertension) as an mPAP of 30 mm Hg, PCWP of 18 mm Hg, and a TPG of 15 mm Hg. We defined eoPH (exercise out of proportion) as an mPAP of 30 mm Hg, PCWP of 18 mm Hg, and a TPG of 15 mm Hg (4). Our hypothesis was that SSc patients with normal exercise physiology and ePVH have a different patho-physiology compared to patients with pulmonary vascular disease (ePH and eoPH).

Secondary Outcome Measures

Name	Time	Method
St. George's Respiratory Questionnaire	24 weeks	To assess overall health, daily life, and perceived well-being in patients with underlying lung disease, the SGRQ is a health-related quality of life questionnaire divided into 3 components : symptoms, activity and impact. The total score (summed weights) can range from 0 to 100 with a lower score denoting a better health status.
Quality of Life (QOL) Based on SF36 and HAQ-DI	24 weeks	Number of participants exceeding minimally important difference estimates on changes in quality of life as assessed by SF-36 (short form 36) quality of life index with mental and physical component scores, or by HAQ-DI (health assessment questionnaire disability index) limitations that may be related to musculoskeletal limitations
HAQ-DI (Health Assessment Questionnaire Disability Index)	24 weeks	Assessing limitations that may be related to musculoskeletal limitations, the HAQ-DI assesses the difficulty a participant has had in the past week in 8 domains of daily living activities: dressing and grooming, arising, eating, walking, hygiene, reach, grip, and other activities. Each activity category consists of 2-3 items in which level of difficulty is scored from 0 to 3 with 0=no difficulty, 1=some difficulty, 2=much difficulty, and 3=unable to do. The 8 domain scores are averaged into a total HAQ-DI score ranging from 0 (no disability) to 3 (completely disabled).
Change in Distance Walked in Six Minutes From Baseline to 24 Week	24 weeks	ATS guideline based assessment with known minimally clinically important difference