We aim to investigate which part of the pulmonary vasculature, the obstructed or non-obstructed, is responsible for the pulmonary vasodilator response.
ID
Source
Brief title
Condition
- Heart failures
- Embolism and thrombosis
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
Macro aggregated albumin (MAA) injected in the peripheral vein distributes via
the right heart (right ventricle) and pulmonary artery over both lungs; its
distribution reflects the distribution of capillary perfusion at the time of
injection.
The primary endpoint is the regional (lobar) change of biodistribution of MAA
over both lungs under the influence of NO assessed with SPECT.
Changes in perfusion counts between obstructed and non-obstructed regions of
the lungs will be assessed to determine the vasodilatory response to NO with
newly developed software (based upon published algorithms). According to our
hypothesis the perfusion in the nonobstructed parts will increase after
inhalation of NO.
In short, to determine the effect of NO on the regional pulmonary perfusion,
using quantitative analysis of the SPECT data.
Secondary outcome
To define the reproducibility of 99mTc- MAA biodistribution as assessed with
SPECT another SPECT perfusion at baseline will be performed.
Background summary
Chronic thromboembolic pulmonary hypertension (CTEPH) is a disease with
progressive pulmonary vascular damage that can develop after an episode of
pulmonary embolism. Interestingly, during cardiac catheterization patients
respond to acute pulmonary vasodilators in different degrees. However, we do
not know where in the pulmonary vasculature this vasodilator response occurs.
Study objective
We aim to investigate which part of the pulmonary vasculature, the obstructed
or non-obstructed, is responsible for the pulmonary vasodilator response.
Study design
This will be an experimental research. In patients with CTEPH we will perform a
single photon emission tomography (SPECT) scan administering Technetium-99m
(99m Tc) labelled macro-aggregated albumin (99m Tc-MAA) to determine the
perfusion distribution within both lungs.
The intervention will be the application of the acute pulmonary vasodilator
nitric oxide (NO). Inhaled NO will be delivered at a dose of 20 parts per
million (ppm) during 5 minutes. After 5 minutes followed by injection of 99m
Tc-MAA via the peripheral catheter, and subsequently followed by SPECT
perfusion scanning.
Study burden and risks
Patients with the suspicion of PH and a history of pulmonary embolism referred
to our hospital will be admitted for diagnostic work up for one week. They
routinely undergo planar ventilation/perfusion scintigraphy combined with SPECT
of the perfusion tracer. The SPECT scan takes approximately 10 minutes (20sec x
32 angles) with the patients in supine position.
For the purpose of this study, we will administer 99mTc- MAA through the
peripheral line while the patients breath NO 20 parts per million (ppm) for 5
minutes. Within approximately half an hour the patients will undergo the SPECT
scan. NO below 20 ppm has no adverse reaction. Doses above 20 ppm have the
increased risk of methemoglobinemia and elevated nitrogen dioxide (NO2) levels.
NB radiation exposure = 1.3 mSv / SPECT scan. Total amount of extra exposure
for the research is 2.6 mSv. To compare, every person living in the Netherlands
receives a natural background radiation dose of 2-2,5 mSv per year.
De Boelelaan 1117
1081 HV Amsterdam
Nederland
De Boelelaan 1117
1081 HV Amsterdam
Nederland
Listed location countries
Age
Inclusion criteria
-mean pulmonary artery pressure > 25 mmHg during right heart catherisation/ pulmonary angiography
-specific signs of chronic thromboembolism during pulmonary angiography
-Ntric monooxide testing during pulmonary angiography cq right heart pressure measuring
Exclusion criteria
-Presence of systemic inflammation.
- Patients with pulmonary hypertension associated with collagen vascular disease, congenital heart disease, pulmonary venous hypertension, left heart failure, hypoxemic lung disease (COPD).
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL26314.029.08 |