Creeping Gradients After TAVR Linked to Poor Longer-Term Outcomes

Early hemodynamic valve deterioration (HVD) after transcatheter aortic valve replacement (TAVR, or TAVI) appeared to have clinical impact by the 4-year mark, according to registry data.

By that point, post-TAVR HVD was associated with lower valve-related long-term clinical efficacy (subdistribution HR 0.42, 95% CI 0.32-0.56), reported Antonin Trimaille, MD, PhD, of Laval University in Quebec City and Strasbourg University Hospital in France, at the EuroPCR meeting in Paris. That endpoint encompassed freedom from bioprosthetic valve failure, stroke, presumably valve-related peripheral embolism, and type 2-4 bleeding secondary to or exacerbated by antiplatelet or anticoagulant therapy given for valve-related concerns.

“This composite outcome is particularly relevant for assessing the impact of early HVD, given its potential role as a surrogate marker of leaflet thrombosis, a condition linked to stroke and reduced bioprosthetic durability. It also accounts for major bleeding events related to antithrombotic therapies used for suspected or confirmed leaflet thrombosis,” the group wrote in a paper published simultaneously in EuroIntervention.

The large-scale observational study included nearly 7,400 consecutive TAVR patients from four countries. Of note, these patients were individuals who underwent regular outpatient clinic visits; cardiac CT imaging was performed only when clinically indicated.

“These findings support early post-TAVI surveillance, including echocardiographic follow-up within 3 months. Given the suspected thrombotic mechanism, further studies should confirm this link and define optimal management, potentially including systematic CT and anticoagulation in case of early HVD,” Trimaille’s group concluded in their report.

The increase of at least 10 mm Hg in mean transaortic gradient on echocardiography within the first 3 months after TAVR that defined early HVD in the study occurred in 3.1% of patients, with a median gradient increase of 12 mm Hg.

The study gets at concerns about structural valve deterioration and valve thrombosis that would affect the durability of TAVR therapy.

In an accompanying editorial, Ron Waksman, MD, and Asa Phichaphop, MD, both of MedStar Washington Hospital Center in Washington, D.C., stressed that structural valve deterioration and valve thrombosis are distinct conditions posing different embolic risks.

“Post-TAVI CT, which was lacking in this study, could help determine the underlying mechanism of HVD and evaluate thrombus morphology on the leaflets,” Waksman and Phichaphop wrote. “It is important to acknowledge that using an early gradient rise as a combined prognostic marker, without mechanistic differentiation, may obscure which pathology actually drives the adverse outcomes observed.”

“Future studies to define the clinical meaningfulness of early valve thrombosis, incorporating post-TAVI CT, are needed to understand these changes and should be a priority for the field,” the duo concluded.

Trimaille and colleagues conducted an international registry study that covered 7,392 consecutive TAVR patients from 16 centers in Canada, Spain, France, and Italy. The analysis selected for those who were still alive at 3 months and who had echocardiographic follow-up data.

The included cohort averaged 81 years old, with 48% being women. The median STS score was 3.9%.

Study authors found that independent predictors of early HVD after TAVR were higher body mass index, TAVR prosthesis size under 26 mm, valve-in-valve procedures, and absence of anticoagulation at discharge.

Besides the primary outcome, early HVD also showed significant associations with the secondary outcomes of:

• Stroke (subdistribution HR 2.32, 95% CI 1.51-3.57)
• Stage 2 or 3 (subdistribution HR 2.74, 95% CI 2.10-3.57) or stage 3 bioprosthetic valve dysfunction (subdistribution HR 3.53, 95% CI 2.15-5.79)
• Bioprosthetic valve failure (subdistribution HR 3.04, 95% CI 2.06-4.52)

Study findings generally held up in a propensity score-matched cohort and across sensitivity analyses, according to the investigators.

Trimaille’s group nevertheless acknowledged the study’s observational design left room for bias and unmeasured confounding. The results also relied on local transthoracic echocardiography without core lab adjudication.

“It is also noteworthy that 40% of patients in the present study were already receiving anticoagulant therapy at discharge, which is quite high and may not reflect a standard practice,” Waksman and Phichaphop cautioned.

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