Pursuit of clinical transcatheter aortic valve implantation gains with advanced imaging tools

Aortic Stenosis (AS) is the most common valvular heart disease in the Western world
and its prevalence is increasing with age, affecting around 3.4% of the elderly patients
> 75 years. The two-year mortality rate is approximately 50% in untreated patients
with symptomatic severe AS. Transcatheter Aortic valve Intervention (TAVI) is a
guideline-recommended treatment for patients >75 years with symptomatic severe
AS. The main aim of this thesis was to compile practical insights into the correlation of
patient phenotype, implantation techniques and transcatheter valve design with TAVI
specific outcome measures.

In chapter 3 and 4 we investigated the impact of the membranous septum (MS) length on the need for PPI with different transcatheter valve platforms. We identified
3 different risk phenotypes for PPI: high risk with a MS-length <3mm, intermediate
risk with a MS-length 3-6mm and low risk with a MS-length >6mm) In chapter 5 and 6 we evaluated a prophylactic pacemaker strategy in patients with pre
procedural RBBB who are at high risk for PPI after TAVI. In chapter 7 we validated the semi
automated Agatston score for aortic valve calcium quantification in the 3Mensio
software package.In chapter 8 we
applied the semi-automated 3Mensio tool to compare AVC between patients with a
bicuspid or tricuspid aortic valve undergoing TAVI. Bicuspid aortic valves contained
significantly more calcium, independent of the measured aortic valve gradient. In chapter 9 we investigated the correlation between AVC and the risk of paravalvular
leakage (PVL) post TAVI. We found that an AVC of 4070 AU for men and 2341 AU for women predicted significant PVL. Chapter 10 was
the first prospective study evaluating FEops HEARTguideTM simulations in the pre
procedural planning of TAVI with the EVOLUT Pro valve in patients with complex
anatomy. The computer simulations accurately predicted the risk for > mild PVL and
need for PPI. Importantly, operators modified their implantation strategy based on
these simulations in 35% of TAVI cases. Chapter 11 was a prospective study to validate the FEops HEARTguideTM simulations for TAVI with the ACURATE NEO2 valve. PVL was accurately predicted. In chapter 12 we demonstrated the safety of default pacing-on-the-LV wire instead of central venous access and temporary pacemaker insertion.
Chapter 13 discusses anticoagulation monitoring. We demonstrated that the point-of-care APTT test correlated better with anti aXa activity than the point-of-care ACT test.In chapter
14 and 15, we pictured a more sobering reality of a disconnect between implantation
measurements by MSCT (the gold standard) and invasive angiography (used during
TAVI procedures). We demonstrated that both the conventional co-planar view and
the recently promoted cusp overlap view do not provide an accurate appreciation
of the implantation depth in the catheterization laboratory.