Inhaled Nitric Oxide (iNO) in Post-Pulmonary Embolism (Post-PE)
Status:
Recruiting
Trial end date:
2022-10-30
Target enrollment:
Participant gender:
Summary
Following acute pulmonary embolism (PE), up to a third of patients develop post-PE syndrome
described as having persistent breathlessness (dyspnea), impaired exercise capacity, and a
reduced quality of life. The post-PE syndrome includes patients with chronic thromboembolic
pulmonary hypertension (CTEPH), patients with chronic thromboembolic disease (CTED) those
with an obstruction of the pulmonary arteries without pulmonary hypertension, and patients
with post-PE related dyspnea without obstruction or pulmonary hypertension. Although
therapies exist for the most severe form of the post-PE syndrome (CTEPH) - for most patients
there are no available disease specific therapies that reduce symptoms. Despite studies
showing increased breathlessness and abnormal exercise responses in patients with CTED, a
detailed examination of what causes breathlessness in post-PE syndrome has never been
undertaken. It is suspected that reduced blood flow to the lungs contributes to the feelings
of breathlessness, particularly during exercise.
This study will use inhaled nitric oxide, a medication that increases blood flow to the
lungs. Inhaled nitric oxide is used primarily in hospitalized patients in the intensive care
unit with respiratory failure, its use in people with post-PE syndrome is experimental. The
investigators believe use of this medication may help to relieve symptoms of breathlessness.
In order to test this medication, in volunteers with post-PE syndrome, the following will be
measured: 1) breathlessness, 2) the signal to breathe sent from the brain to the lungs, 3)
the activity of the muscles involved with breathing and 4) the amount of different gasses in
the blood during exercise. The investigators will compare breathlessness and exercise
tolerance during exercise while receiving: 1) a placebo (normal medical grade air) and 2)
inhaled nitric oxide (a medication that improves blood flow to the lungs). By comparing
symptoms during these two conditions, it is hoped to obtain a better understanding of what
causes breathlessness in people with post-PE syndrome. This clinical research study will
recruit approximately 20 clinically stable participants with CTED or post-PE related
breathlessness.