Prosthesis-patient mismatch after TAVR: 5 key findings related to patients with small annuli
Prosthesis-patient mismatch (PPM) is relatively common after transcatheter aortic valve replacement (TAVR), especially among patients with a small aortic annulus (SAA). Questions remain, however, about what care teams can do to minimize the risk of PPM after TAVR.
The team behind a new study in The American Journal of Cardiology hoped to learn about this phenomenon.[1]
“Although the risk of PPM after TAVR is lower than after SAVR, the rates after TAVR in a high-risk population, such as patients with SAA, still remain high,” wrote first author Lisa Voigtländer-Buschmann, MD, a cardiologist with University Heart & Vascular Center Hamburg, and colleagues. “To date, the approaches to avoid PPM after TAVR are limited.”
Voigtländer-Buschmann et al. tracked data from more than 300 patients with a SAA who underwent transfemoral TAVR from 2014 to 2021. All patients were treated at a single high-volume facility in Germany. SAA was defined as an annulus area less than 400 mm2, and all annulus measurements were confirmed using CT imaging. Patients were treated with a variety of valve types, including balloon-expandable valves from Edwards Lifesciences and Abbott, and self-expanding valves from Medtronic and Boston Scientific.
These are five key takeaways from the group’s analysis:
1. PPM was seen in more than one-third of TAVR patients with a small aortic annulus
Overall, PPM was seen in 38.4% of TAVR patients with a SAA. Half of those patients presented with moderate PPM, and the other half presented with severe PPM. The median age of these patients was 82.1 years old, and 91.4% were women.
2. PPM was more common in patients treated with a balloon-expandable TAVR valve
The PPM rates were 54.9% for patients treated with a balloon-expandable TAVR valve and 29.2% for patients treated with a self-expanding TAVR valve. Of the different valve types used for this study, the balloon-expandable Sapien 3 valves from Edwards Lifesciences were linked to the highest odds of post-TAVR PPM. The self-expanding Evolut valves from Medtronic were linked to the lowest odds, though the PPM rate among that group was still 17.9%.
“It is well-established that self-expanding valves are associated with a lower risk of PPM than balloon-expandable valves and our data support this finding,” the authors wrote. “This applies not only to the supra-annular self-expanding valves, even the intra-annular self-expanding valve design shows better hemodynamic results than balloon-expandable valves.”
3. PPM did not significantly impact long-term mortality
Prior studies have linked PPM to an increased risk of post-TAVR mortality, but that did not appear to be the case for this specific analysis. The overall one-, three- and five-year mortality rates were 13.7%, 25.5% and 43.1%, respectively, and PPM did not influence those numbers in a significant way.
4. Implantation-related factors made little to no impact on the risk of PPM after TAVR
When using a balloon-expandable TAVR valve, a smaller implantation depth was linked to a lower risk of PPM. However, that was the only specific implantation-related factor the group identified that could make a significant impact.
“Our data show that implantation-related factors barely have any influence on the occurrence of PPM, so that once the procedure is planned, the risk of PPM seems to be sealed,” the authors wrote. “Nonetheless, at least in the case of balloon-expandable valves, implantation depth appears to play a significant role, so that this should be taken into account for TAVR in patients with SAA.”
5. PPM should be considered when treating younger TAVR patients
The study’s authors emphasized that their work focused on an elderly cohort. When managing care for younger patients with symptomatic severe aortic stenosis, they wrote, the effects of PPM “should be considered for procedure planning.”
Click here for the full study.