The primary objective is to investigate cerebral perfusion in rest and in response to moderate exercise (handgripping or light cycling) and a visual stimulus in patients with severe aortic valve stenosis prior and after surgical or transcatheter…
ID
Source
Brief title
Condition
- Cardiac valve disorders
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
Cerebral perfusion in rest and in response to moderate exercise (handgripping
or light cycling) and a visual stimulus in patients with aortic valve stenosis
(prior to and after aortic valve replacement) and healthy age-matched
controls.
Secondary outcome
* Cerebral perfusion in rest and in response to exercise in patients and
healthy controls at both arterial (TCD) and microvascular level (arterial spin
labeling MRI).
Background summary
Cardiovascular disease is associated with loss of cognitive functioning. Both
disorders are more common in elderly people. The condition of the heart and the
large vessels determines the flow of blood to the brain and we propose a more
central role for the heart than previously assumed. According to the
traditional paradigm of cerebrovascular autoregulation in humans, the cerebral
perfusion (cerebral blood flow; CBF) is predominantly influenced by the
cerebral perfusion pressure (CPP). Cerebral autoregulation maintains constant
CBF within a wide range of CPP by regulating the cerebrovascular resistance.
However, we and others have demonstrated that a decline in perfusion pressure
within the cerebral autoregulatory range (e.g. when standing up from a sitting
position) may lower CBF. This reduction might be attributed by a change in
systemic flow (cardiac output). CBF has been demonstrated to be substantially
but reversibly reduced in patients with NYHA class III/IV heart failure, with
normalization of CBF following cardiac transplantation [1]. This observation
indicates that redistribution of cardiac output inadequately secures cerebral
perfusion in patients with severe chronic heart failure. We hypothesize that
subnormal recruitment of cardiac output in patients with aortic stenosis
reduces the regional CBF response to small muscle exercise (handgripping or
light cycling) and a visual stimulus, and that the subnormal CBF during
exercise is (partially) restored following adequate surgical aortic valve
replacement (AVR) or transcatheter aorta valve implantation (TAVI).
Study objective
The primary objective is to investigate cerebral perfusion in rest and in
response to moderate exercise (handgripping or light cycling) and a visual
stimulus in patients with severe aortic valve stenosis prior and after surgical
or transcatheter aortic valve replacement.
Study design
Observational. Hemodynamic (e.g. blood pressure, cardiac output and heart
rate), cerebral (CBF velocity by transcranial Doppler ultrasonography and whole
brain CBF by arterial spin labelling MRI) and respiratory parameters (PetCO2)
will be recorded in rest, during a sit-to-stand test and in response to
moderate exercise (handgripping or light cycling) and a visual stimulus. This
study protocol will be performed prior to and after treatment to investigate
the effect of aortic valve replacement (either surgical or by TAVI).
Hemodynamic parameters will also be measured (fingercuff; Nexfin) as well as
kidney perfusion perfusion (ultrasound) during the procedure to study the
direct effect of aortic valve replacement on systemic hemodynamics. Age-matched
volunteers will serve as controls and will follow the same study protocol as
the patients. Study procedures are performed during admission prior to the
aortic valve replacement (2.5 hours), 3 months after the procedure in
combination with the clinical follow-up appointment (2.5 hours) and at 1 year
follow up (5 minutes).
Study burden and risks
No benefits and risks are anticipated for the subjects in the study population
Meibergdreef 9
Amsterdam 1105 AQZ
NL
Meibergdreef 9
Amsterdam 1105 AQZ
NL
Listed location countries
Age
Inclusion criteria
Cohort A (N<=30):
* Age between 50-75 years
* Presence of aortic stenosis (aortic valve area less than 1 cm2)
* Eligible for a surgical aortic valve replacement (AVR)
* Expected aortic valve size of 23-25 mm;Cohort B (N<=30):
Age between 50-95 years
* Presence of aortic stenosis (aortic valve area less than 1 cm2)
* Eligible for transcatheter aorta valve implantation (TAVI)
Exclusion criteria
Cohort A:
* Additional complex surgical procedures indicated (e.g. restoration of aortic root)
* Medical history of neurological disease, active malignant disease/ cardio- toxic treatment and/or venous insufficiency
* Contraindication to MRI exposure (*vragenlijst MRI onderzoek*)
* Smoking or having smoked less than 10 years ago;Cohort B:
* Medical history neurological disease, active malignant disease/ cardio- toxic treatment and/or venous insufficiency
* Contraindication to MRI exposure (*vragenlijst MRI onderzoek*)
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
In other registers
| Register | ID |
|---|---|
| CCMO | NL50524.018.14 |
| OMON | NL-OMON29396 |