Strengths and limitations
There were several limitations to this study, the most important one
being its retrospective, single-center, non-randomized design.
There was also a significant bias due to the “associated procedures”
in the RD-AVR group. In our center, TAVR is indicated in
intermediate-risk patients older than 75 years while RD-AVR is actually
indicated in patients older than 70 years with more comorbidities
needing AVR + CABG. This explains why both subgroups were not similar
before matching. However, our aim was to analyze the impact of each
heart valve prosthesis on outcomes. To this end, we performed a 1:1
propensity-score matched comparison that allowed us to avoid differences
between both groups at the expense of a decrease in the size of the
populations being compared. The variables used for matching were the
subject of lengthy reflection. Euroscore 2 cannot be used in the
propensity score analysis since it includes several variables already
used in the model.
We cannot exclude that subclinical leaflet thrombosis(SLT) could have
promoted CHF in the TAVR group since CT scans were not routinely
performed to confirm the diagnosis [29]. However, all TTE were
performed by experienced cardiologists and CT scans were performed if
there was any doubt of SLT on TTE.
Finally, our current results reflect only two-year outcomes and do not
address the problem of long-term structural valve deterioration (SVD).
An extended FU with a larger number of patients would highlight the
occurrence and the impact of SVD on a long-term prognosis.