The purpose of this study is the evaluation of PAH in patients, who are treated with DAA medication for HCV infection.

Study category and Rationale: This study is without any use of medication or investigations products, therefore this is a category A clinical trail.

Background and Rationale: Pulmonary arterial hypertension (PAH) is a chronic and progressive disease leading to right heart failure and ultimately death in untreated patients. A variety of systemic illnesses have been associated with PAH. Hepatitis C virus (HCV) infection is not defined as a risk factor for PAH. However, compared to a control population higher pulmonary artery pressures are described in patients with HCV. Some case reports indicate association between HCV medication and PAH. Except of a few case reports, to date no clinical study about evidence of PAH in patients with direct-acting-antiviral (DAA) medication for HCV infection has been published.

Objective: The purpose of this study is the evaluation of PAH in patients, who are treated with DAA medication for HCV infection.

Outcomes: The primary outcome of this study is the evaluation of pulmonary artery pressure change using transthoracic doppler-echocardiography (TTE) in patients with a new diagnosis of HCV before and after treatment with DAA medication. The secondary outcomes are the change in left and right ventricular structure and function using TTE in patients with a new diagnosis of HCV before and after treatment with DAA medication.

Study design: A single center prospective, observational cohort study. Inclusion / Exclusion criteria: Inclusion criteria are evidence of HCV infection and age 18-90 years. Patients will be excluded from the study, if there is an inability to provide informed consent and if there are known for existing PAH.

Measurements and procedures: The patients will receive a TTE for the measurement of the pulmonary artery pressure before, during (8 weeks after starting the medication) and 8 weeks after completion of the HCV medication. The whole treatment period will take about 12 weeks.

Study Product / Intervention: The study will use a TTE for measurement of pulmonary artery pressure. This non-invasive, fast investigation (total duration about 20 minutes) is used for years in Cardiology and does not constitute a specific study product.

Number of Participants with Rationale:The study goal ist the înlusion of 50 participants with a newly started DAA medication for HCV infection. Due to the lack of data, a power calculation is not possible. However, if a higher number than 50 participants would be necessary to show a significant rise in pulmonary pressure, a clinical significance is not likely to be relevant.

Study Duration: The study inclusion is planned for 2 year.

Inclusion Criteria:

• Age 18-90 years
• Written informed consent
• New diagnosis of HCV, which requires the initiation of a DAA therapy

Exclusion Criteria:

• Inability to provide informed consent
• Known diagnosis of pulmonary artery hypertension (PAH)
• Dyspnoe NYHA III-IV
• Mean pulmonary artery (PA) pressure (mPAP) of >25 mmHg in the first TTE before start of DAA medication

self-representation of gender identity

All patients who will assign or present with diagnosis of HCV to the infectologist at the Kantonsspital Olten, (community clinic) wasl asked to take part in the study.