Right ventricle remodeling after pulmonary valve replacement and percutaneous pulmonary valve insertion, a functional and histopathological assessment.

Pulmonary regurgitation and (re-)stenosis are a common problem after initial
surgical repair for pulmonary stenosis in patients with congenital heart
disease such as Fallot*s tetralogy and isolated pulmonary valve stenosis.
Re-intervention is indicated in symptomatic patients with severe PR/PS as well
as in asymptomatic patients with progressive loss of RV-function. The timing of
re-intervention however is unclear, preferably re-intervention should take
place before irreversible RV-damage (fibrosis), due to pressure- and volume
overload, occurs. In the past emphasis was paid to the onset of symptoms
instead of preventing right ventricular damage. Because symptoms in right
ventricular failure are linked to the 'poin-of-no-return' (when the right
ventricle doesn't fully recover after pulmonary valve replacement), most likely
a better strategy is to intervene before symptoms arise. To be able to make
reliable criteria for valve replacement we need to better understand the
anatomical and functional impairments of the right ventricle and link this to
histopathological changes. We believe myocardial fibrosis is correlated to this
'point-of-no-return'. In the last decades knowledge concerning RV volumes and
function, and changes in electrocardiographic parameters and exercise
parameters has grown. But, the relation between volums, funcion and
histopathology is missing.

Primary objectives: to investigate functional and histopathological changes of
the right ventricle before and after PVR and PPVI.
To investigate if non-invasive assessment of RV-remodeling using CMR T1 mapping
and T1rho mapping is possible and to validate this with the golden standard of
histopathology. -To investigate RV fibrosis with CMR T1 mapping and T1*-mapping
(T1* relaxation time) and compare with LGE (occurrence of late enhancement) in
patients receiving conservative treatment.
Secondary objectives: to investigate changes in echocardiographic parameters,
electrocardiographic parameters, laboratory parameters (biomarkers), exercise
capacity and quality of life in patients undergoing PVR or PPVI. To assess and
compare the abovementioned parameters (except endomyocardial biopsies) in
patients with RV-overloading not undergoing PVR or PPVI.

Single center, prospective, observational trial with patients undergoing PVR or
PPVI.

Included patients will have extra outpatient clinic visits for
post-interventional CMR, excercise testing, QoL questionnaires, ECG, Holter
monitoring and echocardiography. Endomyocardial biopsies are performed during
PPVI or PVR procedure. Risks of reaction to MR contrast are estimated as very
low. The endomyocardial biopsy performed during valve replacement has a small
risk of serious complications. According to the risk classification advise of
the Federation of University Medical centers (hulplijst risicoclassificatie uit
NFU advies kwaliteitsborging mensgebonden onderzoek) the study has to be graded
as moderate risk.
Patients not undergoing valve replacement will undergo the same studies except
for the endomyocardial biopsy and the echocardography performed
post-intervention and after 1 month follow-up.