Individual Study / Mueller et al.; JMIR Res Protoc. 2019

Observational VENTASTEP Study

Observational VENTASTEP Study

Initiatives -
This study aims to perform parallel digital tracking of daily physical activity parameters, heart rate, and iloprost inhalation data in patients with PAH, before and after starting inhaled iloprost treatment. The primary objective is to investigate correlations between changes in digital measures of daily physical activity and traditional clinical measures. Secondary objectives are to assess iloprost inhalation behavior, the association between daily physical activity measures and time since last inhalation, changes in sleep quality and heart rate, the association of heart rate with daily physical activity measures and iloprost inhalation, and adverse events. Note: All published information has been collected from the article referenced in the Marker Paper box below. Therefore, there may be variations with more advanced versions of the study.
Start Year
This study was funded by Bayer AG (Berlin, Germany) and was conducted in collaboration with the supplier of the patient support program VENTAPLUS (Contra Care GmbH, Nürnberg, Germany) and xbird GmbH (Berlin, Germany), which created the study app (for analysis of daily physical activity and heart rate) and the 6MWD app. Medical writing assistance was provided by Dr Claire Mulligan (Beacon Medical Communications Ltd, Brighton, UK), funded by Bayer AG (Berlin, Germany).


Study design
Patients' cohort

Marker Paper

Mueller C, Stollfuss B, Roitenberg A, Harder J, Richter MJ. Evaluation of Clinical Outcomes and Simultaneous Digital Tracking of Daily Physical Activity, Heart Rate, and Inhalation Behavior in Patients With Pulmonary Arterial Hypertension Treated With Inhaled Iloprost: Protocol for the Observational VENTASTEP Study. JMIR Res Protoc. 2019;8(4):e12144. Published 2019 Apr 15. doi:10.2196/12144

PUBMED 30985279


Sources of Recruitment
  • Individuals

Number of participants

Number of participants
Number of participants with biosamples


Availability of data and biosamples




VENTASTEP is a digital, prospective, observational, multicenter, single-arm cohort study of adult patients with PAH in Germany, starting treatment with inhaled iloprost via the Breelib nebulizer in a real-world setting.
Selection Criteria
  • Germany
Ethnic Origin
Health Status
  • Patients with Pulmonary arterial hypertension (PAH).


Sources of recruitment
  • Specific population
Specific Population
  • Clinic patients

Number of participants

Number of participants
Number of participants with biosamples
Data Collection Event
Heart rate and daily physical activity parameters are monitored digitally using a wearable and a smartphone (the Apple Watch Series 2, 42 mm, Apple Inc and iPhone 6s, Apple Inc; supplied by Vodafone GmbH) with a dedicated study app and a 6MWD app (both created by xbird GmbH).
Start Date
End Date
Data sources
  • Mobile data collection
    • Smartphone
    • Smartwatch and wearables