Long-term results from a clinical trial comparing different treatment approaches in asymptomatic patients with severe aortic stenosis showed a significant benefit for those who received early surgical aortic valve replacement (SAVR) vs conservative care.

Current practice guidelines recommend watchful waiting for patients with severe aortic stenosis who are not yet experiencing symptoms, followed by swift intervention at symptom onset.

Some clinical studies, including an early data readout from the RECOVERY trial, have challenged the guidelines’ preference for conservative management. But until now, those studies have lacked long-term follow-up to assess whether those benefits would be sustained or if, over time, complications such as valve degeneration, thrombosis, or bleeding related to anticoagulation therapy would erode them.

Plan for Long-Term Outcomes

“Because the RECOVERY trial is the first randomized trial comparing early surgery with conservative care in asymptomatic patients with severe aortic stenosis, this study is the only study that provides long-term outcomes of early surgical aortic valve replacement vs conservative care over 10 years,” said Duk-hyun Kang, MD, PhD, a cardiologist at Asan Medical Center Heart Institute in Seoul, South Korea, and lead author of the study. “We believe that early aortic valve replacement may be the preferred strategy for asymptomatic patients with severe aortic stenosis.”

In the trial, Kang and his collaborators enrolled 145 patients with severe aortic stenosis between 2010 and 2015 at four centers in South Korea and randomly assigned them equally to early surgery or conservative care. Patients were required to have a critical stenosis of 0.75 cm² or less plus peak aortic velocity of 4.5 m/s or a mean transaortic pressure gradient of 50 mm Hg or more via Doppler echocardiography.

Patients who had early surgery received a mechanical valve or a biologic prosthesis within 2 months. Meanwhile, among the 72 patients who waited for symptoms, 61 ultimately had SAVR or transcatheter aortic valve replacement (TAVR), and 11 had been admitted for surgery through the emergency department. None died during a valve replacement procedure.

RECOVERY Trial: Past and Present

In 2019, the group reported death from any cause occurred in five patients in the early-surgery group at a median 6.2 years of follow-up and in 15 patients in the conservative-care group, after a median 6.1 years of follow-up.

Now, researchers with the RECOVERY trial have reported that 11 patients in the early-surgery group and 23 patients in the conservative-care group died from any cause within 10 years. The cumulative incidence of operative mortality or death from cardiovascular causes was 1% in the early-surgery group and 19% for those receiving conservative care at 10 years.

Kang noted that early and specific triggers are needed to enable clinical decision-making around the optimal timing of intervention for asymptomatic patients with severe aortic stenosis. “Based on the 10-year results of the RECOVERY trial, aortic velocity over 4.5 m/s represents an appropriate trigger for aortic valve replacement,” he said.

Practice-Changing Results

“Very severe aortic stenosis is not a benign disease, even if patients are asymptomatic,” said Faisal Rahman, BM BCh, an interventional structural cardiologist and director of cardiogenic shock at Johns Hopkins University School of Medicine in Baltimore. “This gives consideration for changing the current practice of performing aortic valve replacement after symptom development.”

Rahman, who was not involved with the RECOVERY trial, noted that the study had several limitations. The trial was conducted wholly in South Korea and so may not be applicable across regions. And 61% of the patients in the study had a bicuspid valve. Also, as the authors acknowledge, the study was small and exercise testing wasn’t consistently used to confirm asymptomatic status. The trial also had a high rate of crossover in the conservative-care group.

Rahman called the RECOVERY trial an important part of his discussions with patients, along with the EARLY TAVR trial, which demonstrated a reduction in cardiovascular hospitalization with TAVR. “Although the RECOVERY study was done with SAVR, I still present the findings to patients who meet the criteria with asymptomatic aortic stenosis regardless of [whether they are considering] SAVR or TAVR,” he said.

Kang and Rahman reported having no relevant financial relationships.

Catherine Shaffer is a freelance science and medical writer with a background in molecular biology and pharmaceutical research. Her work has appeared extensively in scientific trade and mainstream publications and on public radio.