Clinical Trial: Pilot Study to Evaluate Right Ventricular Function With Riociguat in CTEPH

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Evaluation of Right Ventricular Function and Metabolism Following Riociguat for the Treatment of Chronic Thromboembolic Pulmonary Hypertension- Images of Rio

Brief Summary:

Chronic thromboembolic Pulmonary hypertension(CTEPH) is characterized by obstruction of the pulmonary vasculature, leading to increased pulmonary vascular resistance, progressive pulmonary hypertension (PH) and right ventricular failure- most common cause of death for patients with PH. Riociguat, (ADEMPAS) is a member of a new class of drug recently approved in Canada for the treatment of CTEPH.

This pilot study is designed to assess if at least 24 weeks of treatment with riociguat will show changes in glucose metabolism and improved resting myocardial blood flow using positron emission tomography ( PET ) imaging to measure myocardial function. The response between both treatment naive patients as well as patients on maximally tolerated dose of riociguat with tratment duration of at least 3 months will be included.


Detailed Summary:

It remains unclear as to why certain patients with PH develop right heart failure. Several lines of evidence suggests alterations in right ventricular (RV) function may be precipitated by RV ischemia. This ischemia results from both decreased right coronary artery perfusion pressure and from arteriolar- capillary rarefaction. It has been proposed that this contributes to insufficient oxygen delivery needed to support the increase RV demand in right heart failure (RHF), this stimulating glycolytic shift. However, this glycolysis is insufficient to compensate for suppression of glucose oxidation in severe right ventricular hypertrophy (RVH), resulting in a state of RV hibernation and progressive RHF.

This study is designed to assess if 24 weeks of treatment with riociguat will be associated with changes in glucose metabolism and improved RV blood flow using N-13-ammonia (NH3) to measure myocardial perfusion.

We will assess the response in both treatment naive patients as well as patients who have been titrated to maximally tolerated doses of riociguat with total treatment duration of at least 3 months.

The assessment of quantitative myocardial blood flow will be combined with an advanced 3 dimensional echocardiographic assessment of RV volume and function and with cardiac magnetic resonance (MR).


Sponsor: Ottawa Heart Institute Research Corporation

Current Primary Outcome: Evidence of changes in glucose metabolism and myocardial RV blood flow in patients treated with riociguat using PET imaging. [ Time Frame: After 24 weeks of treatment with riociguat. ]

Subjects will undergo FDG (fluorodeoxyglucose, F-18)cardiac positron emission tomography studies (PET) at baseline and 24 weeks to assess regional myocardial blood flow. The assessment of regional myocardial blood flow will be combined with 3D echocardiography and magnetic resonance (MR)


Original Primary Outcome: Same as current

Current Secondary Outcome: Evidence of improved RV function and volumes using 3D echocardiography and magnetic resonance imagining (MRI) [ Time Frame: baseline and 24 weeks ]

The assessment of will be obtained by 3D echocardiography and MRI to evaluate RV function.


Original Secondary Outcome: Same as current

Information By: Ottawa Heart Institute Research Corporation

Dates:
Date Received: March 17, 2014
Date Started: May 2014
Date Completion:
Last Updated: January 31, 2017
Last Verified: January 2017