Oversizing reduces PVL when implanting Medtronic’s newer self-expanding TAVR valves
High degrees of valve oversizing can significantly reduce the risk of mild, moderate or severe paravalvular leak (PVL) when implanting a new-generation Evolut transcatheter aortic valve replacement (TAVR) valve, according to a recent analysis published in Circulation: Cardiovascular Interventions.[1]
“The increasing use of TAVR to treat severe aortic stenosis in younger and less frail patients comes with the need to lower its potential associated complications to a minimum,” wrote first author Silvia Mas-Peiro, MD, PhD, a researcher with the Quebec Heart and Lung Institute, and colleagues. “Among the most common downsides of a TAVR procedure, the presence of residual PVLs has been shown to have a substantial prognostic impact on outcomes after TAVR. Although most prior studies have focused on moderate-to-severe PVL, recent data also revealed the potential importance of mild PVL, particularly in self-expandable valve recipients.”
Mas-Peiro et al. tracked data from more than 700 TAVR patients who received a self-expanding Evolut Pro, Evolut Pro+ or Evolut FX valve from Medtronic. The most common valve size was 29 mm (45.9%), with 26 mm (36%) coming in at No. 2. The median patient age was 83 years old, and 58.9% of patients were women. The rates of in-hospital mortality and stroke were 2.4% and 4.3%, respectively, while a permanent pacemaker was required for 17.6% of patients. Residual PVL, as confirmed using echocardiography, was present 35.6% of the time. The PVL was moderate or severe 3% of the time.
How valve oversizing impacted clinical outcomes, the risk of paravalvular leak
The median degree of valve oversizing in this analysis was 20%. Lower degrees of valve oversizing—anything equal to or less than 20%—were used for half of the study’s TAVR procedures. Higher degrees of valve oversizing—anything more than 20%—were used for the other half.
Overall, the degree of valve oversizing did not appear to impact in-hospital patient outcomes. However, a higher degree of oversizing was associated with a significantly lower PVL rate (30.2%) than a lower degree of oversizing (40.9%).
“With the expected increased use of the new iteration of the Evolut system after the promising hemodynamic results of the SMART trial, it seems essential trying to reduce to the bare minimum any degree of PVL following TAVR with the Evolut system,” the authors wrote. “Our group and others have previously shown that a higher oversizing degree correlated with lower rates of PVL in patients undergoing TAVR with the old-generation Evolut R valve. In the present study, we found that this also occurs with the newest iterations of the Evolut platform.”
Learning more about post-dilation
Another key takeaway from this analysis was the updated look at the potential impact of post-dilation, which occurred after 16.1% of TAVR procedures. Researchers did identify a slight connection between post-dilation and PVL, but it failed to reach statistical significance. This was different from previous studies where the association between post-dilation and PVL was more substantial.
“This could probably be due to the low number of post-dilations that are performed nowadays, usually limited to cases with moderate or severe PVL immediately after valve implantation,” the authors wrote. “Also, post-dilation has been associated with an increase in some complications. It would be of great interest to verify in future series with a larger number of cases with post-dilation whether the baseline condition or the age of the patient has an influence on the operator’s decision to post-dilate.”
Many factors to consider in TAVR sizing
Mas-Peiro and colleagues also noted device selection before TAVR can be a complex decision that involves many moving parts.
“Although oversizing plays a crucial role in the reduction of PVL, a number of factors need to be kept in mind when selecting the appropriate device size, particularly in patients with an annular size between two consecutive existing prosthesis sizes,” the group wrote. “Among others, it is essential to confirm with the manufacturer’s chart that both the diameters of the sinus of Valsalva and the diameter of primary peripheral access are sufficient for the chosen valve size and the chosen sheath, respectively. In some cases, this may be a limitation for selecting a larger valve in borderline cases.”
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Michael has more than 18 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.