A Mobile Health Intervention in Pulmonary Arterial Hypertension

Patients with pulmonary arterial hypertension (PAH) have severely reduced exercise capacity
and reduced quality of life. At diagnosis, most PAH patients are New York Heart Association
(NYHA) functional class III with symptoms of fatigue and shortness of breath with less than
ordinary activity. Physical activity confers multiple benefits relevant to PAH
pathophysiology including improvements in endothelial function, energy metabolism, and right
ventricular (RV) function. Increasing physical activity is highly efficacious in PAH,
resulting in six-minute walk distance (6MWD) improvement that exceeds the effect of
medications.

The goal of this proposal is to adapt and test the feasibility of our mHealth intervention to
increase physical activity in a geographically diverse PAH population. In secondary aims, we
will assess conventional PAH trial outcomes (6MWD, quality of life) and physiologic
mechanisms by which increasing activity may improve exercise capacity.

The investigator hypothesizes that an mHealth intervention is feasible and will increase
physical activity in subjects with PAH. This study proposes a randomized trial of unblinded
step tracking with smart texts tracking for 12 weeks. Participants will wear a display-free
triaxial accelerometer, which will continuously transmit data to a compatible smartphone
(owned by 75% of our PAH population). Efficacy endpoints have been selected to mirror FDA
criteria for drug approval in PAH. The following aims will be tested:

Aim 1: To test the feasibility of an mHealth intervention to increase step counts in patients
with PAH. Fifty PAH patients will be randomized to the mHealth intervention or usual activity
for 12 weeks. The primary endpoint will be daily step count during Week 12. Secondary
endpoints will assess step target achievement, daily activity time, and aerobic time. The
fidelity of data collection and text transmission will also be assessed.

Aim 2: To examine the effect of an mHealth intervention on exercise capacity and quality of
life. Participants will complete a six minute walk test and the emPHasis-10 questionnaire at
baseline and 12 weeks. The primary endpoint will be six minute walk distance. Secondary
endpoints will be emPHasis-10 quality of life scale score, Borg dyspnea score, and resting
heart rate.

Aim 3: To examine the effect of an mHealth intervention on mechanisms of improved exercise
capacity. Subjects will undergo echocardiography, blood draw, and body composition
assessment. The primary endpoint will be RV longitudinal strain. Secondary endpoints will be
the homeostatic model assessment of insulin resistance, lean muscle and fat mass, and B-type
natriuretic peptide.

Inclusion Criteria:

1. Aged 18 or older.

2. Diagnosed with idiopathic, heritable, or associated (connective tissue disease, drugs,
or toxins) pulmonary arterial hypertension (PAH) according to World Health
Organization consensus recommendations.

3. Stable PAH-specific medication regimen for three months prior to enrollment. Subjects
with only a single diuretic adjustment in the prior three months will be included.

4. Subjects must own a Bluetooth capable modern smartphone capable of receiving and
sending text messages and an active data plan.

Exclusion Criteria:

1. Prohibited from normal activity due to wheelchair bound status, bed bound status,
reliance on a cane/walker, activity-limiting angina, activity-limiting osteoarthritis,
or other condition.

2. Pregnancy.

3. Diagnosis of PAH etiology other than idiopathic, heritable, or associated.

4. Forced vital capacity <70% predicted.

5. Functional class IV heart failure.

6. Requirement of > 1 diuretic adjustment in the prior three months.

7. Preferred form of activity is not measured by an activity tracker (swimming, yoga, ice
skating, stair master, or activities on wheels such as bicycling or rollerblading).