Assessment of Myocardial Fibrosis in Aortic STenosis
Assessment of Myocardial Fibrosis in Aortic STenosis
This observational cohort study studies the impact myocardial fibrosis has on patients with
 severe aortic stenosis undergoing aortic valve replacement.
Aortic stenosis is the most common valvular disease in the Western World. It is a slow
 evolving degenerative disease caused by gradual accumulation of calcium in the valve.
 Untreated it is fatal. Reduced opening area of the valve increases afterload on the left
 ventricle (LV), which leads to raised end-diastolic pressure in the LV. Increased wall stress
 leads to LV hypertrophy and expansion of the extracellular matrix. An abnormally high
 extracellular volume fraction is called myocardial fibrosis (MF), which causes increased LV
 stiffness, diastolic dysfunction, dilatation of the left atrium and in the end heart failure.

 The standard of treatment for aortic stenosis is an operation, aortic valve repair (AVR),
 where a mechanical or biological valve replaces the old one. The operation involves a
 substantial risk of postoperative mortality, and is therefore delayed until the patient
 develops symptoms such as shortness of breath, chest pains or syncope. For most patients AVR
 causes significant symptom reduction and reduced mortality. Recent studies have indicated
 that patient with severe MF, which may account for up to one third of the patients treated,
 have little or no symptom improvement and an increased mortality after AVR. This raises
 concern that their LV is so severely fibrotic that it is beyond repair. These patients may
 not benefit from an operation, or should possibly have had AVR performed at an earlier stage
 of the disease.

 Today, cardiac fibrosis can be detected by a biopsy which is invasive. Late Gadolinium and
 T1-mapping cardiac Magnetic Resonance imaging (MRi) has recently been evaluated as a new
 method to detect MF, but this method is costly and contraindicated for some patients. Cardiac
 Computerized Tomography (CT) has been proposed as a method to evaluate MF, but has not been
 properly validated yet.

 In this study we compare different methods (biopsy, MRi, CT, echocardiography and different
 biomarkers) to evaluate the extent of MF in 130 patients with severe aortic stenosis
 undergoing AVR. We will focus on their symptom improvement and survival rate one year after
 the operation. Our main thesis is that patients with severe fibrosis before the operation
 have little or no symptom improvement and reduced survival after the operation. If this
 thesis is correct, it will question which patients to offer AVR. Some patients we operate
 today may have no benefit from the operation because the left ventricle is damaged from
 severe fibrosis, and some patients from who we withhold the operation today because they are
 asymptomatic may benefit from AVR before they develop severe fibrosis.
Inclusion Criteria:

 -  Severe aortic valve stenosis (AVA ≤1cm2).

 -  Scheduled for aortic valve replacement.

 -  Signed consent

 Exclusion Criteria:

 -  At least moderate mitral regurgitation or stenosis.

 -  Primary aortic insufficiency.

 -  Persistent or permanent atrial fibrillation/flutter.

 -  CKD with e-GFR < 40 ml/kg/min.

 -  Pacemaker or Implantable Cardioverter Defibrillator (ICD).