Fixing TAVR Injuries Doesn’t Help Outcomes

Transcatheter closure of holes between the atria that persist after transcatheter aortic valve repair (TAVR) didn’t improve exercise capacity compared with conservative treatment in the small MITHRAS trial.

Six-minute walking distance at 5 months post-closure was similar to conservatively-treated patients without significant change in either group, Philipp Lurz, MD, PhD, of the Heart Center Leipzig at University of Leipzig, Germany, reported at the virtual TCT Connect conference and online in Circulation.

Closing these iatrogenic atrial septal defects (iASDs, which are created by the transseptal access sheaths for TAVR in up to 50% of cases) also had no impact on 1-year mortality and heart failure rehospitalization. Those with iASD, regardless of intervention, had higher risk than those without relevant iASD at the 1-month assessment.

Lurz advocated individualized decision-making on closure, with the trial giving no general recommendations to close iASDs.

TCT Connect session discussant Mayra Guerrero, MD, of Mayo Clinic in Rochester, Minnesota, agreed.

“I suspect that patients who have persistent shunt at 1 month are a sicker patient population with higher left atrial pressure that is driving the patency of iatrogenic ASD and also driving the size of the left-to-right shunt,” she said. “Persistent iASD may be a marker of disease and not really a cause.”

The groups were well balanced in baseline characteristics but patients in the iASD arm had lower ejection fraction, more functional mitral regurgitation at the time of initial intervention, and lower right ventricular function compared with no iASD.

Lurz pointed out that the shunting can get smaller over time if it’s just stretched without a tear, although it’s not clear if this is due to an improvement in filling pressures on the left side or because right-sided pressures rise.

“Given the data, you can make a strong argument in not doing anything at 1 month, as long as the patient is doing reasonably well and just do follow-up in those,” he said. “If they then come back with clear signs of right heart failure… I think these are the ones where the decision is a little bit easier.”

The trial included 80 patients with a fraction of pulmonary perfusion to fraction of systemic perfusion ≥1.3 and predominantly left-to-right shunt seen at 1 month post-TMVR, 95% of which had been with the MitraClip. They were randomized to interventional iASD closure with a Figulla Flex Occluder or conservative treatment. Another 235 TMVR patients without any iASD were included for comparison.

Secondary endpoints, including symptoms, NT-proBNP, and peripheral edema also didn’t differ between treatment groups.

The procedure was successful and uncomplicated in all patients, reducing left-to-right shunting compared with the conservative group. No subgroups benefited more than others.

Limitations included the single-center design, relatively small number of patients, lack of stratification by mitral regurgitation etiology, and that shunting volumes might have been too small to detect benefits of closure.

Also, “left-to-right shunting across iASD can decrease over time without interventional closure, so inclusion and closure of iASD might have been too early to differentiate treatment benefits,” Lurz suggested.

Disclosures

The trial was partially funded by Occlutech.

Lurz disclosed relationships with ReCor, Occlutech, Edwards Lifesciences, Abbott, and Medtronic.

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