Restoration of cardiac function and regional pulmonary blood flow in chronic thromboembolic pulmonary hypertension after pulmonary endarterectomy assessed during exercise by magnetic resonance imaging

Chronic thromboembolic pulmonary hypertension (CTEPH) results from incomplete
resolution of pulmonary thromboembolism. If left untreated, CTEPH is a
progressive disorder with a poor prognosis. Pulmonary endarterectomy (PEA)
represents the therapy of choice for patients with surgically accessible CTEPH.
PEA is associated with near-normalization of pulmonary hemodynamics in most
operated patients.
As a consequence, exercise tolerance improves significantly, however, does not
fully normalize in part of the patients. Recently, it was suggested by
echocardiography that some patients may suffer from functional limitations due
to exercise induced (residual) pulmonary hypertension. This might be the
consequence of more distally localized chronic thrombi that were not be removed
by PEA. Due to the excercised-induced pulmonary hypertension, exercise
tolerance in these patients might be limited due to a cardiac limitation.
Recently, we demonstrated, using MRI measurements during exercise, that in
patients with pulmonary arterial hypertension exercise capacity was limited due
to an impaired RV stroke volume response during exercise.

To assess, by use of MRI measurements during exercise, the level of restoration
of cardiac function, and to study whether excercise limitation in CTEPH
patients after a hemodynamically succesful PEA is caused by an impaired RV
stroke volume response during excercise.
To study the effect of PEA on the restoration of regional blood flow.
Finally, to study the relation between the level of restoration of cardiac
function and the restoration of regional blood flow.

MRI measurements of cardiac function at rest and during submaximal excercise.
Sub-maximal exercise is defined by reaching 70% of the maximum workload
determined at a routinely performed maximal exercise test on a cycle ergometer
prior to PEA.
Asssessment of regional blood flow at rest.

To asses the level of restoration of cardiac function and regional blood flow,
the investigations will be repated after one year in patients in whom PEA did
result in near-nomalization of the pulmonary artery pressure (meanPAP * 30
mmHg).

As far as currently known, MRI has no negative impact on patient health
Gadolineum is routinely used and is considered very safe in use