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No Clarity on Clinical Impact of Post-TAVR Leaflet Thrombosis

— Cases of HALT, RLM largely limited to one leaflet

Last Updated June 24, 2020
MedpageToday

Reduced leaflet motion (RLM) could be tied to neither clinical outcomes nor changes in valve hemodynamics 2 years after transcatheter aortic valve replacement (TAVR), an observational study showed.

The incidence of RLM was 15.9% at 30 days and 15.5% at 6 months in a nested prospective substudy of the Portico U.S. IDE randomized trial. Only one leaflet was affected in the bulk of these RLM cases, reported Hasan Jilaihawi, MD, of NYU Langone Health in New York City, at the Transcatheter Valve Therapy (TVT) virtual meeting.

In a landmark analysis, clinical outcomes from days 4 to 180 were similar between people who had RLM 30 days and peers who didn't. For example, the composite of death, stroke, or transient ischemic attack reached 3.9% vs 6.7% of these groups, respectively (P=0.75).

By 2 years, this outcome was still similarly likely between groups (15.4% vs 13.9%, log-rank P=0.84).

Mean gradients over 2 years were also no different among patients who had no RLM, progressive RLM, persistent RLM, or regression of RLM between 30 days and 6 months, Jilaihawi noted, adding that RLM regression occurred regardless of oral anticoagulation use.

Across devices, the incidence of hypo-attenuated leaflet thickening (HALT) was 31.2% at 30 days and 33.2% at 6 months. As was the case with RLM, HALT was largely limited to one leaflet.

Thus, the findings support current practice for the treatment and monitoring for subclinical leaflet thrombosis after TAVR, suggested Samir Kapadia, MD, of Cleveland Clinic, during the TVT session.

"We are not routinely screening because at what time frame [would] we screen? Since it comes and goes, what do we make out of it? One-third of patients have it at most, then a third of them are resolved, a third get more, and a third stay the same," he said.

Patients whose gradients increase by 10 mm Hg or more on follow-up should get a CT scan and be put on anticoagulation. "Otherwise, we are not doing the scan," according to Kapadia.

For those who only have HALT and no increase in gradients, the approach is to reduce the time to the next follow-up from 6 to 3 months and not change anticoagulation, said TVT discussant Julinda Mehilli, MD, of Ludwig-Maximilians University and the German Heart Center in Munich.

Study participants were at high or extreme surgical risk with symptomatic severe aortic stenosis. The had randomized 750 people to the Portico or any commercial TAVR device, of whom 364 had early CT/TEE data on leaflet mobility and were included in this substudy.

People who received the Portico valve showed more RLM at 30 days (24.6% vs 6.9% for a Edwards Lifesciences valve vs 5.8% for a Medtronic valve). This was no longer significant at 6 months (19.5% vs 11.8% vs 8.8%), according to Jilaihawi.

The predictors of RLM in Portico valves turned out to be anticoagulation at 30 days (OR 0.29, 95% CI 0.10-0.82), native aortic valve area (OR 0.03, 95% CI 0.002-0.35), and STS-PROM score (OR 1.14, 95% CI 1.01-1.29).

The observational study was limited by the substantial number of missing scans and the limited time frame for which was evaluated. Data were also not powered to draw any conclusions regarding clinical outcomes and valve performance, the presenter cautioned.

Future studies should determine if RLM is correlated with long-term valve durability, he said. "When we talk about durability, we need to look at least over 5 years or even more. It is possible we will start to see some changes at that time point. But that is a subject of further study."

Given the elevated stroke rate in HALT versus RLM patients, it would be helpful to have more data on the relationship between HALT and outcomes, said Gregg Stone, MD, of Mount Sinai Icahn School of Medicine and the Cardiovascular Research Foundation in New York City. He suggested a prospective registry of 10,000 patients.

  • author['full_name']

    Nicole Lou is a reporter for 鶹ý, where she covers cardiology news and other developments in medicine.

Disclosures

Jilaihawi disclosed relevant relationships with Boston Scientific and Medtronic, as well as support from Abbott Vascular, Edwards Lifesciences, Medtronic, and HLT.

Primary Source

Transcatheter Valve Therapy

Jilaihawi H, et al "First prospective randomized clinical trial assessing incidence of reduced leaflet motion and its clinical impact following transcatheter aortic valve implantation" TVT 2020.