The Venous Congestion Validation Study

Rationale
Venous congestion due to elevated right atrial pressure (RAP) contributes to
impaired organ function. In fact, it may be even more important than arterial
hypoperfusion as it impedes drainage of blood flow, resulting in accumulation
of deoxygenated blood, causing cell damage and increased fibrosis, as shown for
kidney and liver function (1-3). It is, however, completely unknown if this
also applies to the brain. Still, it has recently been shown that venous
abnormalities are related to structural brain changes seen in cerebral small
vessel disease (SVD). Jugular vein reflux measured by Duplex, which is related
to RAP (4) might be related to white matter changes(5) and to increased
intracranial pressure(6). Therefore, we hypothesize that elevated RAP and
venous congestion might be related to structural and functional abnormalities
of the brain independently of cardiac output. By analyzing the MRI data from
the Heart -Brain Connection study (multicenter CVON research), we have the
unique opportunity to address this clinically highly relevant question.
However, assessment of RAP and venous congestion by MRI has not yet been
validated. We hypothesize that MRI measurement of flow and structure of vena
cava superior is capable to estimate venous congestion with sufficient
accuracy.

Objective
The aim of this study is to validate a minimal correlation of 0.6 between right
atrial pressure measure by right heart catheterization and flow and dimension
of the vena cava superior determined by MRI. The correlation of >=0.6 is chosen
because lower correlation would not be clinically meaningful. In addition,
echocardiographic assessment of flow and dimension of the vena cava inferior
will be used as comparison since this is the currently most often used tool to
non-invasively assess right atrial pressure.

The study will be conducted as a content validation study in the Maastricht
University Medical Centre + (MUMC+). A total of 30 patients undergoing a
right-heart catheterisation for clinical purposes will be included. The
indication usually is heart failure and/or pulmonary hypertension. All patients
will undergo the same standardized set of clinical and imaging tests after a
standardized informed consent procedure.

All research data are collected through standard medical procedures and no
experimental intervention is conducted. The additional risk of this study is
very low and is limited to discomfort related to the additional procedures.
There will be no administration of MRI contrast media, unless clinically
indicated (in case patients require an MRI due to clinical reasons, the study
MRI and the clinical MRI will obviously be combined). The burden of
participation consists of time investment at both baseline (60 minutes for
clinical and echocardiography and a maximum of 60 minutes for MRI scanning) and
the risk of fatigue. There is no direct benefit for the participants. However,
this study will contribute to knowledge of hemodynamic factors associated with
cognitive decline which form possible targets for future therapy.