Introduction: In transcatheter aortic valve replacement (TAVR), prosthesis oversizing prevents paravalvular regurgitation. Although the estimated extent of oversizing depends on annular measurements, oversizing strategies are not well established.
Hypothesis: The aim of our study was to evaluate the impact of different degrees of valve oversizing based on multislice computed tomography (MSCT) on the outcome of patients.
Methods: Patients with severe and symptomatic aortic stenosis scheduled for TAVR with a self-expanding valve, were prospectively enrolled. All patients underwent pre-procedural MSCT. According to the measurements, patients were classified into three groups for the degree of oversizing: normal (10-15%), moderate (15-20%) and severe (>20%) depending on the ratio between valve prosthesis diameter and the perimeter-derived annulus diameter based on MSCT. The main endpoint was mid-term mortality and secondary endpoints were the Valve Academic Research Consortium (VARC-2) end-points.
Results: Overall, 177 patients (mean age: 79±7years, mean logEuroscore 24.9±10%, NYHA III-IV: 90%) were consecutively included in the study. Mean annulus area was 23.3±2.5mm2 and mean perimeter was 74.36±7.27mm. Ninety-one patients (51%) had normal oversizing, 67 patients moderate (38%) and 19 patients (11%) severe oversizing. There were no cases of annular rupture. The primary clinical end-point occurred in 38 patients (21%) during a follow-up period of 24±12 months. While all-cause mortality rates were similar in all groups (24.1% for normal sizing versus 21.9% for moderate oversizing versus 22.9%, for severe oversizing, p=0.93), post-procedural new pacemaker (PPM) implantation rate was significantly higher in severe compared to the moderate and normal oversizing groups respectively (63.2%, versus 38.8%, versus 30.8%, p=0.03). Patients with normal oversizing had a trend of higher rate of significant paravalvular leak (at least moderate) compared to patients with moderate and severe oversizing (18.7%, versus 7.5%, versus 5.3%, p=0.058).
Conclusions: Despite a higher rate of pacemaker implantation, a higher extent of valve oversizing in patients undergoing TAVR, seems to reduce the degree of paravalvular leak.