Discussion
In more recent years, in UK there has been an increase in the use of the
SC and axillary route, including percutaneous approaches performed under
local anaesthetic, and a corresponding decline in TA access. SC and TA
still remain the preferred alternative to the default femoral delivery,
and they are fundamental in case of iliofemoral hostility, which may
contraindicate its navigation. Despite the progressive reduction in the
calibre of TAVI delivery systems, which are nowadays available on the
market, in a significant proportion of patients, which range from 10 to
15%, small vessels, calcification, previous stenting deployment,
tortuosity, and pathological stenosis may preclude a percutaneous
femoral approach. Because patients who received a surgical alternative
access commonly have a worse risk-profile, it could be useful to analyse
which worse outcomes are related to the patient rather than to the
procedure. There is a lack of data prospectively comparing outcomes and
long-term survival after SC vs TA TAVI. In this regard, the UK TAVI
national registry offer the opportunity to explore whether there was a
difference in outcomes and survival between TA and SC and this is the
reason because we decided to focus our analysis on this wide pool of
data. Our study found that the SC approach was associated with increased
short-term (12 months), but not long-term (up to 96 months) mortality.
Compared to TA, the SC approach has the advantages of obviating
separation of the pleura, and thus may reduce postoperative pain and
respiratory complications that are commonly related to each thoracotomy.
On the other hands, SC it can be restricted by anatomical features such
as tortuosity or small vessel calibre. In case of pre-existing left
internal mammary artery bypass graft SC may also expose patient to the
risk of acute myocardial ischemia during navigation. Furthermore, the
relative lack of a muscular component to the subclavian wall makes this
artery more incline to iatrogenic dissection. This study collected,
compared, and analysed surgical TAVI implantation in a large sample of
patients in a national real-world setting. Considering that there is a
paucity of data directly comparing outcomes for SC and TA TAVI
approaches, in the absence of randomised controlled trial data,
prospectively collected observational data offer the best alternative
for such kind of comparison. We reported a large series of SC and TA
cases over a long period and each limitation of no-randomized
observational study was robustly corrected by an accurate and rigorous
propensity score analysis. We aimed to describe and analyse the whole
pool of data regarding the early and intermediate experience of an
entire country (UK), and to clarify the outcomes associated with the
main two different surgical choices, which are alternative to the
femoral delivery. We found no difference in long-term mortality between
SC and TA, and their respective Kaplan-Meier survival curves were almost
overlapped. According to our analysis, SC had faster recovery process
than TA, in fact the median in hospital length of stay was 2.8 days less
than those with the TA approach. Conversely, the main downside of SC was
the high rate of PPI, but this outcome is likely to be related to the
use of Core Valve™ (Medtronic) for the SC approach. However, in our
dataset, PPI after TAVI did not affect the overall long-term survival.
As with any operative technique, the choice to select a specific
approach is determined by different combinations of patients’
comorbidity, vascular anatomy/pathology, transcatheter heart valve type,
availability of new performing devices on the market, and skill mixing
along with the expertise and experience of the entire Heart Team, who
remains the key factor to lead to the best choice tailored for each
patient.