Valve durability after TAVR: Cardiologists track how deterioration influences outcomes
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As transcatheter aortic valve replacement (TAVR) continues to grow more common in younger patients with severe aortic stenosis, researchers have made it a priority to learn as much about the durability of TAVR valves as possible.
A new analysis in JACC: Cardiovascular Interventions explored that very topic, tracking signs of biological valve dysfunction (BVD) and hemodynamic valve deterioration (HVD) in nearly 2,500 TAVR patients.[1] The study’s authors focused on echocardiography data and contemporary definitions of BVD and HVD for their research.
“Recently, the Valve Academic Research Consortium-3 (VARC-3) presented an updated definition of BVD incorporating the underlying pathology, the hemodynamic significance, and the clinical consequences,” wrote co-lead authors Bashir Alaour, MD, PhD, and Daijiro Tomii, MD, two cardiologists with Bern University Hospital in Switzerland, and colleagues. “The updated definition relies on the temporal dynamic change of the echocardiographic hemodynamic parameters of the aortic valve prosthesis rather than fixed reference values as diagnostic cutoff thresholds for HVD and its stages. Reports on the long-term risk and outcomes of HVD defined according to the updated VARC-3 criteria are rare.”
Defining hemodynamic valve deterioration
The updated VARC-3 criteria in question defined moderate HVD as “an increase in mean transvalvular gradient ≥10 mm Hg resulting in a mean gradient ≥20 mm Hg with concomitant decrease in effective orifice area (EOA) ≥0.3 cm2 detected ≥90 days post-TAVR compared with echocardiographic assessment at discharge or 30 days after TAVR, or a new occurrence or increase of ≥1 grade of intraprosthetic aortic regurgitation (AR) resulting in ≥ moderate AR ≥90 days post-TAVR.”
The updated VARC-3 criteria defined moderate HVD as “an increase in mean transvalvular gradient ≥20 mm Hg resulting in mean gradient ≥30 mm Hg with a concomitant decrease in EOA ≥0.6 cm2 at ≥90 days post-TAVR compared with echocardiographic assessment at discharge or 30 days after TAVR, or a new occurrence or increase of ≥2 grades of intraprosthetic AR resulting in ≥ severe AR at ≥90 days post-TAVR.”
Diving into the data
This analysis included 2,403 TAVR patients who underwent treatment from 2007 to 2022 at Bern University Hospital. All data came from the Bern TAVI registry. The mean patient age was 81.8 years old, 48.4% were women and the median Society of Thoracic Surgeons score was 3.8. The median follow-up period was 376 days.
Overall, 6.9% of patients presented with moderate HVD during follow-up. Severe HVD, meanwhile, was seen in 1.9% of patients. HVD was more common in male patients, patients with a lower body mass index and patients who did not present with prior coronary artery bypass grafting. A higher transvalvular mean aortic valve gradient also appeared to increase a patient’s long-term risk of HVD. The type and size of TAVR valve used during the procedure did not appear to significantly impact the risk of HVD.
Researchers used cumulative event curves to track the probability of HVD over time for each patient. According to these curves, moderate or severe HVD was seen in 2.2% of patients after one year, 10.8% of patients after five years and 25.6% after 10 years.
In addition, aortic valve complex calcium volume, residual AR at discharge and treatment with oral anticoagulants were all independent predictors of HVD following TAVR.
“The potential reasons for why AVC calcium could predict HVD are manifold, spanning from the potential underexpansion and deformation of the prosthesis, which could increase the risk of thrombosis and subsequently HVD, to the potential acceleration of prosthetic leaflet calcification in patients who exhibited high AVC calcium burden before TAVR, due to ongoing and persistent calcium promoting metabolic or other upstream pathways,” the authors wrote.
Does TAVR valve deterioration impact patient survival?
Patients with and without HVD did not have significantly different rates of all-cause mortality, cardiovascular mortality or endocarditis. Aortic valve reinterventions, however, were much more common in patients who showed signs of HVD, highlighting the importance of tracking hemodynamic data during scheduled follow-up appointments.
Also, according to the study’s authors, the unexpected relationship between HVD and some clinical outcomes stood out as a reason for concern.
“Rather alarmingly, HVD was not associated with any increased rates of New York Heart Association functional class III or IV, indicating an insidious nature of HVD and underlining the role of routine regular echocardiographic follow-up,” the authors wrote.
Click here to read the full study in JACC: Cardiovascular Interventions, an American College of Cardiology journal.
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.